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Diffstat (limited to 'contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 9720 | 
1 files changed, 9720 insertions, 0 deletions
diff --git a/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp new file mode 100644 index 000000000000..f9f431db55be --- /dev/null +++ b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -0,0 +1,9720 @@ +//===-- SelectionDAGBuilder.cpp - Selection-DAG building ------------------===// +// +//                     The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This implements routines for translating from LLVM IR into SelectionDAG IR. +// +//===----------------------------------------------------------------------===// + +#include "SelectionDAGBuilder.h" +#include "SDNodeDbgValue.h" +#include "llvm/ADT/BitVector.h" +#include "llvm/ADT/Optional.h" +#include "llvm/ADT/SmallSet.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/Analysis/AliasAnalysis.h" +#include "llvm/Analysis/BranchProbabilityInfo.h" +#include "llvm/Analysis/ConstantFolding.h" +#include "llvm/Analysis/Loads.h" +#include "llvm/Analysis/TargetLibraryInfo.h" +#include "llvm/Analysis/ValueTracking.h" +#include "llvm/Analysis/VectorUtils.h" +#include "llvm/CodeGen/Analysis.h" +#include "llvm/CodeGen/FastISel.h" +#include "llvm/CodeGen/FunctionLoweringInfo.h" +#include "llvm/CodeGen/GCMetadata.h" +#include "llvm/CodeGen/GCStrategy.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineJumpTableInfo.h" +#include "llvm/CodeGen/MachineModuleInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/CodeGen/SelectionDAG.h" +#include "llvm/CodeGen/SelectionDAGTargetInfo.h" +#include "llvm/CodeGen/StackMaps.h" +#include "llvm/CodeGen/WinEHFuncInfo.h" +#include "llvm/IR/CallingConv.h" +#include "llvm/IR/ConstantRange.h" +#include "llvm/IR/Constants.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/DebugInfo.h" +#include "llvm/IR/DerivedTypes.h" +#include "llvm/IR/Function.h" +#include "llvm/IR/GetElementPtrTypeIterator.h" +#include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/InlineAsm.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/IntrinsicInst.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/LLVMContext.h" +#include "llvm/IR/Module.h" +#include "llvm/IR/Statepoint.h" +#include "llvm/MC/MCSymbol.h" +#include "llvm/Support/CommandLine.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/Support/raw_ostream.h" +#include "llvm/Target/TargetFrameLowering.h" +#include "llvm/Target/TargetInstrInfo.h" +#include "llvm/Target/TargetIntrinsicInfo.h" +#include "llvm/Target/TargetLowering.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/Target/TargetSubtargetInfo.h" +#include <algorithm> +#include <utility> +using namespace llvm; + +#define DEBUG_TYPE "isel" + +/// LimitFloatPrecision - Generate low-precision inline sequences for +/// some float libcalls (6, 8 or 12 bits). +static unsigned LimitFloatPrecision; + +static cl::opt<unsigned, true> +LimitFPPrecision("limit-float-precision", +                 cl::desc("Generate low-precision inline sequences " +                          "for some float libcalls"), +                 cl::location(LimitFloatPrecision), +                 cl::init(0)); +// Limit the width of DAG chains. This is important in general to prevent +// DAG-based analysis from blowing up. For example, alias analysis and +// load clustering may not complete in reasonable time. It is difficult to +// recognize and avoid this situation within each individual analysis, and +// future analyses are likely to have the same behavior. Limiting DAG width is +// the safe approach and will be especially important with global DAGs. +// +// MaxParallelChains default is arbitrarily high to avoid affecting +// optimization, but could be lowered to improve compile time. Any ld-ld-st-st +// sequence over this should have been converted to llvm.memcpy by the +// frontend. It is easy to induce this behavior with .ll code such as: +// %buffer = alloca [4096 x i8] +// %data = load [4096 x i8]* %argPtr +// store [4096 x i8] %data, [4096 x i8]* %buffer +static const unsigned MaxParallelChains = 64; + +static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL, +                                      const SDValue *Parts, unsigned NumParts, +                                      MVT PartVT, EVT ValueVT, const Value *V, +                                      bool IsABIRegCopy); + +/// getCopyFromParts - Create a value that contains the specified legal parts +/// combined into the value they represent.  If the parts combine to a type +/// larger than ValueVT then AssertOp can be used to specify whether the extra +/// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT +/// (ISD::AssertSext). +static SDValue getCopyFromParts(SelectionDAG &DAG, const SDLoc &DL, +                                const SDValue *Parts, unsigned NumParts, +                                MVT PartVT, EVT ValueVT, const Value *V, +                                Optional<ISD::NodeType> AssertOp = None, +                                bool IsABIRegCopy = false) { +  if (ValueVT.isVector()) +    return getCopyFromPartsVector(DAG, DL, Parts, NumParts, +                                  PartVT, ValueVT, V, IsABIRegCopy); + +  assert(NumParts > 0 && "No parts to assemble!"); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue Val = Parts[0]; + +  if (NumParts > 1) { +    // Assemble the value from multiple parts. +    if (ValueVT.isInteger()) { +      unsigned PartBits = PartVT.getSizeInBits(); +      unsigned ValueBits = ValueVT.getSizeInBits(); + +      // Assemble the power of 2 part. +      unsigned RoundParts = NumParts & (NumParts - 1) ? +        1 << Log2_32(NumParts) : NumParts; +      unsigned RoundBits = PartBits * RoundParts; +      EVT RoundVT = RoundBits == ValueBits ? +        ValueVT : EVT::getIntegerVT(*DAG.getContext(), RoundBits); +      SDValue Lo, Hi; + +      EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), RoundBits/2); + +      if (RoundParts > 2) { +        Lo = getCopyFromParts(DAG, DL, Parts, RoundParts / 2, +                              PartVT, HalfVT, V); +        Hi = getCopyFromParts(DAG, DL, Parts + RoundParts / 2, +                              RoundParts / 2, PartVT, HalfVT, V); +      } else { +        Lo = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[0]); +        Hi = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[1]); +      } + +      if (DAG.getDataLayout().isBigEndian()) +        std::swap(Lo, Hi); + +      Val = DAG.getNode(ISD::BUILD_PAIR, DL, RoundVT, Lo, Hi); + +      if (RoundParts < NumParts) { +        // Assemble the trailing non-power-of-2 part. +        unsigned OddParts = NumParts - RoundParts; +        EVT OddVT = EVT::getIntegerVT(*DAG.getContext(), OddParts * PartBits); +        Hi = getCopyFromParts(DAG, DL, +                              Parts + RoundParts, OddParts, PartVT, OddVT, V); + +        // Combine the round and odd parts. +        Lo = Val; +        if (DAG.getDataLayout().isBigEndian()) +          std::swap(Lo, Hi); +        EVT TotalVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); +        Hi = DAG.getNode(ISD::ANY_EXTEND, DL, TotalVT, Hi); +        Hi = +            DAG.getNode(ISD::SHL, DL, TotalVT, Hi, +                        DAG.getConstant(Lo.getValueSizeInBits(), DL, +                                        TLI.getPointerTy(DAG.getDataLayout()))); +        Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, TotalVT, Lo); +        Val = DAG.getNode(ISD::OR, DL, TotalVT, Lo, Hi); +      } +    } else if (PartVT.isFloatingPoint()) { +      // FP split into multiple FP parts (for ppcf128) +      assert(ValueVT == EVT(MVT::ppcf128) && PartVT == MVT::f64 && +             "Unexpected split"); +      SDValue Lo, Hi; +      Lo = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[0]); +      Hi = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[1]); +      if (TLI.hasBigEndianPartOrdering(ValueVT, DAG.getDataLayout())) +        std::swap(Lo, Hi); +      Val = DAG.getNode(ISD::BUILD_PAIR, DL, ValueVT, Lo, Hi); +    } else { +      // FP split into integer parts (soft fp) +      assert(ValueVT.isFloatingPoint() && PartVT.isInteger() && +             !PartVT.isVector() && "Unexpected split"); +      EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits()); +      Val = getCopyFromParts(DAG, DL, Parts, NumParts, PartVT, IntVT, V); +    } +  } + +  // There is now one part, held in Val.  Correct it to match ValueVT. +  // PartEVT is the type of the register class that holds the value. +  // ValueVT is the type of the inline asm operation. +  EVT PartEVT = Val.getValueType(); + +  if (PartEVT == ValueVT) +    return Val; + +  if (PartEVT.isInteger() && ValueVT.isFloatingPoint() && +      ValueVT.bitsLT(PartEVT)) { +    // For an FP value in an integer part, we need to truncate to the right +    // width first. +    PartEVT = EVT::getIntegerVT(*DAG.getContext(),  ValueVT.getSizeInBits()); +    Val = DAG.getNode(ISD::TRUNCATE, DL, PartEVT, Val); +  } + +  // Handle types that have the same size. +  if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits()) +    return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); + +  // Handle types with different sizes. +  if (PartEVT.isInteger() && ValueVT.isInteger()) { +    if (ValueVT.bitsLT(PartEVT)) { +      // For a truncate, see if we have any information to +      // indicate whether the truncated bits will always be +      // zero or sign-extension. +      if (AssertOp.hasValue()) +        Val = DAG.getNode(*AssertOp, DL, PartEVT, Val, +                          DAG.getValueType(ValueVT)); +      return DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val); +    } +    return DAG.getNode(ISD::ANY_EXTEND, DL, ValueVT, Val); +  } + +  if (PartEVT.isFloatingPoint() && ValueVT.isFloatingPoint()) { +    // FP_ROUND's are always exact here. +    if (ValueVT.bitsLT(Val.getValueType())) +      return DAG.getNode( +          ISD::FP_ROUND, DL, ValueVT, Val, +          DAG.getTargetConstant(1, DL, TLI.getPointerTy(DAG.getDataLayout()))); + +    return DAG.getNode(ISD::FP_EXTEND, DL, ValueVT, Val); +  } + +  llvm_unreachable("Unknown mismatch!"); +} + +static void diagnosePossiblyInvalidConstraint(LLVMContext &Ctx, const Value *V, +                                              const Twine &ErrMsg) { +  const Instruction *I = dyn_cast_or_null<Instruction>(V); +  if (!V) +    return Ctx.emitError(ErrMsg); + +  const char *AsmError = ", possible invalid constraint for vector type"; +  if (const CallInst *CI = dyn_cast<CallInst>(I)) +    if (isa<InlineAsm>(CI->getCalledValue())) +      return Ctx.emitError(I, ErrMsg + AsmError); + +  return Ctx.emitError(I, ErrMsg); +} + +/// getCopyFromPartsVector - Create a value that contains the specified legal +/// parts combined into the value they represent.  If the parts combine to a +/// type larger than ValueVT then AssertOp can be used to specify whether the +/// extra bits are known to be zero (ISD::AssertZext) or sign extended from +/// ValueVT (ISD::AssertSext). +static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL, +                                      const SDValue *Parts, unsigned NumParts, +                                      MVT PartVT, EVT ValueVT, const Value *V, +                                      bool IsABIRegCopy) { +  assert(ValueVT.isVector() && "Not a vector value"); +  assert(NumParts > 0 && "No parts to assemble!"); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue Val = Parts[0]; + +  // Handle a multi-element vector. +  if (NumParts > 1) { +    EVT IntermediateVT; +    MVT RegisterVT; +    unsigned NumIntermediates; +    unsigned NumRegs; + +    if (IsABIRegCopy) { +      NumRegs = TLI.getVectorTypeBreakdownForCallingConv( +          *DAG.getContext(), ValueVT, IntermediateVT, NumIntermediates, +          RegisterVT); +    } else { +      NumRegs = +          TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT, IntermediateVT, +                                     NumIntermediates, RegisterVT); +    } + +    assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!"); +    NumParts = NumRegs; // Silence a compiler warning. +    assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!"); +    assert(RegisterVT.getSizeInBits() == +           Parts[0].getSimpleValueType().getSizeInBits() && +           "Part type sizes don't match!"); + +    // Assemble the parts into intermediate operands. +    SmallVector<SDValue, 8> Ops(NumIntermediates); +    if (NumIntermediates == NumParts) { +      // If the register was not expanded, truncate or copy the value, +      // as appropriate. +      for (unsigned i = 0; i != NumParts; ++i) +        Ops[i] = getCopyFromParts(DAG, DL, &Parts[i], 1, +                                  PartVT, IntermediateVT, V); +    } else if (NumParts > 0) { +      // If the intermediate type was expanded, build the intermediate +      // operands from the parts. +      assert(NumParts % NumIntermediates == 0 && +             "Must expand into a divisible number of parts!"); +      unsigned Factor = NumParts / NumIntermediates; +      for (unsigned i = 0; i != NumIntermediates; ++i) +        Ops[i] = getCopyFromParts(DAG, DL, &Parts[i * Factor], Factor, +                                  PartVT, IntermediateVT, V); +    } + +    // Build a vector with BUILD_VECTOR or CONCAT_VECTORS from the +    // intermediate operands. +    EVT BuiltVectorTy = +        EVT::getVectorVT(*DAG.getContext(), IntermediateVT.getScalarType(), +                         (IntermediateVT.isVector() +                              ? IntermediateVT.getVectorNumElements() * NumParts +                              : NumIntermediates)); +    Val = DAG.getNode(IntermediateVT.isVector() ? ISD::CONCAT_VECTORS +                                                : ISD::BUILD_VECTOR, +                      DL, BuiltVectorTy, Ops); +  } + +  // There is now one part, held in Val.  Correct it to match ValueVT. +  EVT PartEVT = Val.getValueType(); + +  if (PartEVT == ValueVT) +    return Val; + +  if (PartEVT.isVector()) { +    // If the element type of the source/dest vectors are the same, but the +    // parts vector has more elements than the value vector, then we have a +    // vector widening case (e.g. <2 x float> -> <4 x float>).  Extract the +    // elements we want. +    if (PartEVT.getVectorElementType() == ValueVT.getVectorElementType()) { +      assert(PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements() && +             "Cannot narrow, it would be a lossy transformation"); +      return DAG.getNode( +          ISD::EXTRACT_SUBVECTOR, DL, ValueVT, Val, +          DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); +    } + +    // Vector/Vector bitcast. +    if (ValueVT.getSizeInBits() == PartEVT.getSizeInBits()) +      return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); + +    assert(PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements() && +      "Cannot handle this kind of promotion"); +    // Promoted vector extract +    return DAG.getAnyExtOrTrunc(Val, DL, ValueVT); + +  } + +  // Trivial bitcast if the types are the same size and the destination +  // vector type is legal. +  if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits() && +      TLI.isTypeLegal(ValueVT)) +    return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); + +  if (ValueVT.getVectorNumElements() != 1) { +     // Certain ABIs require that vectors are passed as integers. For vectors +     // are the same size, this is an obvious bitcast. +     if (ValueVT.getSizeInBits() == PartEVT.getSizeInBits()) { +       return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); +     } else if (ValueVT.getSizeInBits() < PartEVT.getSizeInBits()) { +       // Bitcast Val back the original type and extract the corresponding +       // vector we want. +       unsigned Elts = PartEVT.getSizeInBits() / ValueVT.getScalarSizeInBits(); +       EVT WiderVecType = EVT::getVectorVT(*DAG.getContext(), +                                           ValueVT.getVectorElementType(), Elts); +       Val = DAG.getBitcast(WiderVecType, Val); +       return DAG.getNode( +           ISD::EXTRACT_SUBVECTOR, DL, ValueVT, Val, +           DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); +     } + +     diagnosePossiblyInvalidConstraint( +         *DAG.getContext(), V, "non-trivial scalar-to-vector conversion"); +     return DAG.getUNDEF(ValueVT); +  } + +  // Handle cases such as i8 -> <1 x i1> +  EVT ValueSVT = ValueVT.getVectorElementType(); +  if (ValueVT.getVectorNumElements() == 1 && ValueSVT != PartEVT) +    Val = ValueVT.isFloatingPoint() ? DAG.getFPExtendOrRound(Val, DL, ValueSVT) +                                    : DAG.getAnyExtOrTrunc(Val, DL, ValueSVT); + +  return DAG.getBuildVector(ValueVT, DL, Val); +} + +static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &dl, +                                 SDValue Val, SDValue *Parts, unsigned NumParts, +                                 MVT PartVT, const Value *V, bool IsABIRegCopy); + +/// getCopyToParts - Create a series of nodes that contain the specified value +/// split into legal parts.  If the parts contain more bits than Val, then, for +/// integers, ExtendKind can be used to specify how to generate the extra bits. +static void getCopyToParts(SelectionDAG &DAG, const SDLoc &DL, SDValue Val, +                           SDValue *Parts, unsigned NumParts, MVT PartVT, +                           const Value *V, +                           ISD::NodeType ExtendKind = ISD::ANY_EXTEND, +                           bool IsABIRegCopy = false) { +  EVT ValueVT = Val.getValueType(); + +  // Handle the vector case separately. +  if (ValueVT.isVector()) +    return getCopyToPartsVector(DAG, DL, Val, Parts, NumParts, PartVT, V, +                                IsABIRegCopy); + +  unsigned PartBits = PartVT.getSizeInBits(); +  unsigned OrigNumParts = NumParts; +  assert(DAG.getTargetLoweringInfo().isTypeLegal(PartVT) && +         "Copying to an illegal type!"); + +  if (NumParts == 0) +    return; + +  assert(!ValueVT.isVector() && "Vector case handled elsewhere"); +  EVT PartEVT = PartVT; +  if (PartEVT == ValueVT) { +    assert(NumParts == 1 && "No-op copy with multiple parts!"); +    Parts[0] = Val; +    return; +  } + +  if (NumParts * PartBits > ValueVT.getSizeInBits()) { +    // If the parts cover more bits than the value has, promote the value. +    if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) { +      assert(NumParts == 1 && "Do not know what to promote to!"); +      Val = DAG.getNode(ISD::FP_EXTEND, DL, PartVT, Val); +    } else { +      if (ValueVT.isFloatingPoint()) { +        // FP values need to be bitcast, then extended if they are being put +        // into a larger container. +        ValueVT = EVT::getIntegerVT(*DAG.getContext(),  ValueVT.getSizeInBits()); +        Val = DAG.getNode(ISD::BITCAST, DL, ValueVT, Val); +      } +      assert((PartVT.isInteger() || PartVT == MVT::x86mmx) && +             ValueVT.isInteger() && +             "Unknown mismatch!"); +      ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); +      Val = DAG.getNode(ExtendKind, DL, ValueVT, Val); +      if (PartVT == MVT::x86mmx) +        Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); +    } +  } else if (PartBits == ValueVT.getSizeInBits()) { +    // Different types of the same size. +    assert(NumParts == 1 && PartEVT != ValueVT); +    Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); +  } else if (NumParts * PartBits < ValueVT.getSizeInBits()) { +    // If the parts cover less bits than value has, truncate the value. +    assert((PartVT.isInteger() || PartVT == MVT::x86mmx) && +           ValueVT.isInteger() && +           "Unknown mismatch!"); +    ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); +    Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val); +    if (PartVT == MVT::x86mmx) +      Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); +  } + +  // The value may have changed - recompute ValueVT. +  ValueVT = Val.getValueType(); +  assert(NumParts * PartBits == ValueVT.getSizeInBits() && +         "Failed to tile the value with PartVT!"); + +  if (NumParts == 1) { +    if (PartEVT != ValueVT) { +      diagnosePossiblyInvalidConstraint(*DAG.getContext(), V, +                                        "scalar-to-vector conversion failed"); +      Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); +    } + +    Parts[0] = Val; +    return; +  } + +  // Expand the value into multiple parts. +  if (NumParts & (NumParts - 1)) { +    // The number of parts is not a power of 2.  Split off and copy the tail. +    assert(PartVT.isInteger() && ValueVT.isInteger() && +           "Do not know what to expand to!"); +    unsigned RoundParts = 1 << Log2_32(NumParts); +    unsigned RoundBits = RoundParts * PartBits; +    unsigned OddParts = NumParts - RoundParts; +    SDValue OddVal = DAG.getNode(ISD::SRL, DL, ValueVT, Val, +                                 DAG.getIntPtrConstant(RoundBits, DL)); +    getCopyToParts(DAG, DL, OddVal, Parts + RoundParts, OddParts, PartVT, V); + +    if (DAG.getDataLayout().isBigEndian()) +      // The odd parts were reversed by getCopyToParts - unreverse them. +      std::reverse(Parts + RoundParts, Parts + NumParts); + +    NumParts = RoundParts; +    ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits); +    Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val); +  } + +  // The number of parts is a power of 2.  Repeatedly bisect the value using +  // EXTRACT_ELEMENT. +  Parts[0] = DAG.getNode(ISD::BITCAST, DL, +                         EVT::getIntegerVT(*DAG.getContext(), +                                           ValueVT.getSizeInBits()), +                         Val); + +  for (unsigned StepSize = NumParts; StepSize > 1; StepSize /= 2) { +    for (unsigned i = 0; i < NumParts; i += StepSize) { +      unsigned ThisBits = StepSize * PartBits / 2; +      EVT ThisVT = EVT::getIntegerVT(*DAG.getContext(), ThisBits); +      SDValue &Part0 = Parts[i]; +      SDValue &Part1 = Parts[i+StepSize/2]; + +      Part1 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, +                          ThisVT, Part0, DAG.getIntPtrConstant(1, DL)); +      Part0 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, +                          ThisVT, Part0, DAG.getIntPtrConstant(0, DL)); + +      if (ThisBits == PartBits && ThisVT != PartVT) { +        Part0 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part0); +        Part1 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part1); +      } +    } +  } + +  if (DAG.getDataLayout().isBigEndian()) +    std::reverse(Parts, Parts + OrigNumParts); +} + + +/// getCopyToPartsVector - Create a series of nodes that contain the specified +/// value split into legal parts. +static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &DL, +                                 SDValue Val, SDValue *Parts, unsigned NumParts, +                                 MVT PartVT, const Value *V, +                                 bool IsABIRegCopy) { + +  EVT ValueVT = Val.getValueType(); +  assert(ValueVT.isVector() && "Not a vector"); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); + +  if (NumParts == 1) { +    EVT PartEVT = PartVT; +    if (PartEVT == ValueVT) { +      // Nothing to do. +    } else if (PartVT.getSizeInBits() == ValueVT.getSizeInBits()) { +      // Bitconvert vector->vector case. +      Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val); +    } else if (PartVT.isVector() && +               PartEVT.getVectorElementType() == ValueVT.getVectorElementType() && +               PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements()) { +      EVT ElementVT = PartVT.getVectorElementType(); +      // Vector widening case, e.g. <2 x float> -> <4 x float>.  Shuffle in +      // undef elements. +      SmallVector<SDValue, 16> Ops; +      for (unsigned i = 0, e = ValueVT.getVectorNumElements(); i != e; ++i) +        Ops.push_back(DAG.getNode( +            ISD::EXTRACT_VECTOR_ELT, DL, ElementVT, Val, +            DAG.getConstant(i, DL, TLI.getVectorIdxTy(DAG.getDataLayout())))); + +      for (unsigned i = ValueVT.getVectorNumElements(), +           e = PartVT.getVectorNumElements(); i != e; ++i) +        Ops.push_back(DAG.getUNDEF(ElementVT)); + +      Val = DAG.getBuildVector(PartVT, DL, Ops); + +      // FIXME: Use CONCAT for 2x -> 4x. + +      //SDValue UndefElts = DAG.getUNDEF(VectorTy); +      //Val = DAG.getNode(ISD::CONCAT_VECTORS, DL, PartVT, Val, UndefElts); +    } else if (PartVT.isVector() && +               PartEVT.getVectorElementType().bitsGE( +                 ValueVT.getVectorElementType()) && +               PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements()) { + +      // Promoted vector extract +      Val = DAG.getAnyExtOrTrunc(Val, DL, PartVT); +    } else { +      if (ValueVT.getVectorNumElements() == 1) { +        Val = DAG.getNode( +            ISD::EXTRACT_VECTOR_ELT, DL, PartVT, Val, +            DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); + +      } else { +        assert(PartVT.getSizeInBits() > ValueVT.getSizeInBits() && +               "lossy conversion of vector to scalar type"); +        EVT IntermediateType = +            EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits()); +        Val = DAG.getBitcast(IntermediateType, Val); +        Val = DAG.getAnyExtOrTrunc(Val, DL, PartVT); +      } +    } + +    assert(Val.getValueType() == PartVT && "Unexpected vector part value type"); +    Parts[0] = Val; +    return; +  } + +  // Handle a multi-element vector. +  EVT IntermediateVT; +  MVT RegisterVT; +  unsigned NumIntermediates; +  unsigned NumRegs; +  if (IsABIRegCopy) { +    NumRegs = TLI.getVectorTypeBreakdownForCallingConv( +        *DAG.getContext(), ValueVT, IntermediateVT, NumIntermediates, +        RegisterVT); +  } else { +    NumRegs = +        TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT, IntermediateVT, +                                   NumIntermediates, RegisterVT); +  } +  unsigned NumElements = ValueVT.getVectorNumElements(); + +  assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!"); +  NumParts = NumRegs; // Silence a compiler warning. +  assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!"); + +  // Convert the vector to the appropiate type if necessary. +  unsigned DestVectorNoElts = +      NumIntermediates * +      (IntermediateVT.isVector() ? IntermediateVT.getVectorNumElements() : 1); +  EVT BuiltVectorTy = EVT::getVectorVT( +      *DAG.getContext(), IntermediateVT.getScalarType(), DestVectorNoElts); +  if (Val.getValueType() != BuiltVectorTy) +    Val = DAG.getNode(ISD::BITCAST, DL, BuiltVectorTy, Val); + +  // Split the vector into intermediate operands. +  SmallVector<SDValue, 8> Ops(NumIntermediates); +  for (unsigned i = 0; i != NumIntermediates; ++i) { +    if (IntermediateVT.isVector()) +      Ops[i] = +          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, IntermediateVT, Val, +                      DAG.getConstant(i * (NumElements / NumIntermediates), DL, +                                      TLI.getVectorIdxTy(DAG.getDataLayout()))); +    else +      Ops[i] = DAG.getNode( +          ISD::EXTRACT_VECTOR_ELT, DL, IntermediateVT, Val, +          DAG.getConstant(i, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); +  } + +  // Split the intermediate operands into legal parts. +  if (NumParts == NumIntermediates) { +    // If the register was not expanded, promote or copy the value, +    // as appropriate. +    for (unsigned i = 0; i != NumParts; ++i) +      getCopyToParts(DAG, DL, Ops[i], &Parts[i], 1, PartVT, V); +  } else if (NumParts > 0) { +    // If the intermediate type was expanded, split each the value into +    // legal parts. +    assert(NumIntermediates != 0 && "division by zero"); +    assert(NumParts % NumIntermediates == 0 && +           "Must expand into a divisible number of parts!"); +    unsigned Factor = NumParts / NumIntermediates; +    for (unsigned i = 0; i != NumIntermediates; ++i) +      getCopyToParts(DAG, DL, Ops[i], &Parts[i*Factor], Factor, PartVT, V); +  } +} + +RegsForValue::RegsForValue() { IsABIMangled = false; } + +RegsForValue::RegsForValue(const SmallVector<unsigned, 4> ®s, MVT regvt, +                           EVT valuevt, bool IsABIMangledValue) +    : ValueVTs(1, valuevt), RegVTs(1, regvt), Regs(regs), +      RegCount(1, regs.size()), IsABIMangled(IsABIMangledValue) {} + +RegsForValue::RegsForValue(LLVMContext &Context, const TargetLowering &TLI, +                           const DataLayout &DL, unsigned Reg, Type *Ty, +                           bool IsABIMangledValue) { +  ComputeValueVTs(TLI, DL, Ty, ValueVTs); + +  IsABIMangled = IsABIMangledValue; + +  for (EVT ValueVT : ValueVTs) { +    unsigned NumRegs = IsABIMangledValue +                           ? TLI.getNumRegistersForCallingConv(Context, ValueVT) +                           : TLI.getNumRegisters(Context, ValueVT); +    MVT RegisterVT = IsABIMangledValue +                         ? TLI.getRegisterTypeForCallingConv(Context, ValueVT) +                         : TLI.getRegisterType(Context, ValueVT); +    for (unsigned i = 0; i != NumRegs; ++i) +      Regs.push_back(Reg + i); +    RegVTs.push_back(RegisterVT); +    RegCount.push_back(NumRegs); +    Reg += NumRegs; +  } +} + +SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG, +                                      FunctionLoweringInfo &FuncInfo, +                                      const SDLoc &dl, SDValue &Chain, +                                      SDValue *Flag, const Value *V) const { +  // A Value with type {} or [0 x %t] needs no registers. +  if (ValueVTs.empty()) +    return SDValue(); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); + +  // Assemble the legal parts into the final values. +  SmallVector<SDValue, 4> Values(ValueVTs.size()); +  SmallVector<SDValue, 8> Parts; +  for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) { +    // Copy the legal parts from the registers. +    EVT ValueVT = ValueVTs[Value]; +    unsigned NumRegs = RegCount[Value]; +    MVT RegisterVT = IsABIMangled +                         ? TLI.getRegisterTypeForCallingConv(RegVTs[Value]) +                         : RegVTs[Value]; + +    Parts.resize(NumRegs); +    for (unsigned i = 0; i != NumRegs; ++i) { +      SDValue P; +      if (!Flag) { +        P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT); +      } else { +        P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT, *Flag); +        *Flag = P.getValue(2); +      } + +      Chain = P.getValue(1); +      Parts[i] = P; + +      // If the source register was virtual and if we know something about it, +      // add an assert node. +      if (!TargetRegisterInfo::isVirtualRegister(Regs[Part+i]) || +          !RegisterVT.isInteger() || RegisterVT.isVector()) +        continue; + +      const FunctionLoweringInfo::LiveOutInfo *LOI = +        FuncInfo.GetLiveOutRegInfo(Regs[Part+i]); +      if (!LOI) +        continue; + +      unsigned RegSize = RegisterVT.getSizeInBits(); +      unsigned NumSignBits = LOI->NumSignBits; +      unsigned NumZeroBits = LOI->Known.countMinLeadingZeros(); + +      if (NumZeroBits == RegSize) { +        // The current value is a zero. +        // Explicitly express that as it would be easier for +        // optimizations to kick in. +        Parts[i] = DAG.getConstant(0, dl, RegisterVT); +        continue; +      } + +      // FIXME: We capture more information than the dag can represent.  For +      // now, just use the tightest assertzext/assertsext possible. +      bool isSExt = true; +      EVT FromVT(MVT::Other); +      if (NumSignBits == RegSize) { +        isSExt = true;   // ASSERT SEXT 1 +        FromVT = MVT::i1; +      } else if (NumZeroBits >= RegSize - 1) { +        isSExt = false;  // ASSERT ZEXT 1 +        FromVT = MVT::i1; +      } else if (NumSignBits > RegSize - 8) { +        isSExt = true;   // ASSERT SEXT 8 +        FromVT = MVT::i8; +      } else if (NumZeroBits >= RegSize - 8) { +        isSExt = false;  // ASSERT ZEXT 8 +        FromVT = MVT::i8; +      } else if (NumSignBits > RegSize - 16) { +        isSExt = true;   // ASSERT SEXT 16 +        FromVT = MVT::i16; +      } else if (NumZeroBits >= RegSize - 16) { +        isSExt = false;  // ASSERT ZEXT 16 +        FromVT = MVT::i16; +      } else if (NumSignBits > RegSize - 32) { +        isSExt = true;   // ASSERT SEXT 32 +        FromVT = MVT::i32; +      } else if (NumZeroBits >= RegSize - 32) { +        isSExt = false;  // ASSERT ZEXT 32 +        FromVT = MVT::i32; +      } else { +        continue; +      } +      // Add an assertion node. +      assert(FromVT != MVT::Other); +      Parts[i] = DAG.getNode(isSExt ? ISD::AssertSext : ISD::AssertZext, dl, +                             RegisterVT, P, DAG.getValueType(FromVT)); +    } + +    Values[Value] = getCopyFromParts(DAG, dl, Parts.begin(), +                                     NumRegs, RegisterVT, ValueVT, V); +    Part += NumRegs; +    Parts.clear(); +  } + +  return DAG.getNode(ISD::MERGE_VALUES, dl, DAG.getVTList(ValueVTs), Values); +} + +void RegsForValue::getCopyToRegs(SDValue Val, SelectionDAG &DAG, +                                 const SDLoc &dl, SDValue &Chain, SDValue *Flag, +                                 const Value *V, +                                 ISD::NodeType PreferredExtendType) const { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  ISD::NodeType ExtendKind = PreferredExtendType; + +  // Get the list of the values's legal parts. +  unsigned NumRegs = Regs.size(); +  SmallVector<SDValue, 8> Parts(NumRegs); +  for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) { +    unsigned NumParts = RegCount[Value]; + +    MVT RegisterVT = IsABIMangled +                         ? TLI.getRegisterTypeForCallingConv(RegVTs[Value]) +                         : RegVTs[Value]; + +    if (ExtendKind == ISD::ANY_EXTEND && TLI.isZExtFree(Val, RegisterVT)) +      ExtendKind = ISD::ZERO_EXTEND; + +    getCopyToParts(DAG, dl, Val.getValue(Val.getResNo() + Value), +                   &Parts[Part], NumParts, RegisterVT, V, ExtendKind); +    Part += NumParts; +  } + +  // Copy the parts into the registers. +  SmallVector<SDValue, 8> Chains(NumRegs); +  for (unsigned i = 0; i != NumRegs; ++i) { +    SDValue Part; +    if (!Flag) { +      Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i]); +    } else { +      Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i], *Flag); +      *Flag = Part.getValue(1); +    } + +    Chains[i] = Part.getValue(0); +  } + +  if (NumRegs == 1 || Flag) +    // If NumRegs > 1 && Flag is used then the use of the last CopyToReg is +    // flagged to it. That is the CopyToReg nodes and the user are considered +    // a single scheduling unit. If we create a TokenFactor and return it as +    // chain, then the TokenFactor is both a predecessor (operand) of the +    // user as well as a successor (the TF operands are flagged to the user). +    // c1, f1 = CopyToReg +    // c2, f2 = CopyToReg +    // c3     = TokenFactor c1, c2 +    // ... +    //        = op c3, ..., f2 +    Chain = Chains[NumRegs-1]; +  else +    Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Chains); +} + +void RegsForValue::AddInlineAsmOperands(unsigned Code, bool HasMatching, +                                        unsigned MatchingIdx, const SDLoc &dl, +                                        SelectionDAG &DAG, +                                        std::vector<SDValue> &Ops) const { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); + +  unsigned Flag = InlineAsm::getFlagWord(Code, Regs.size()); +  if (HasMatching) +    Flag = InlineAsm::getFlagWordForMatchingOp(Flag, MatchingIdx); +  else if (!Regs.empty() && +           TargetRegisterInfo::isVirtualRegister(Regs.front())) { +    // Put the register class of the virtual registers in the flag word.  That +    // way, later passes can recompute register class constraints for inline +    // assembly as well as normal instructions. +    // Don't do this for tied operands that can use the regclass information +    // from the def. +    const MachineRegisterInfo &MRI = DAG.getMachineFunction().getRegInfo(); +    const TargetRegisterClass *RC = MRI.getRegClass(Regs.front()); +    Flag = InlineAsm::getFlagWordForRegClass(Flag, RC->getID()); +  } + +  SDValue Res = DAG.getTargetConstant(Flag, dl, MVT::i32); +  Ops.push_back(Res); + +  unsigned SP = TLI.getStackPointerRegisterToSaveRestore(); +  for (unsigned Value = 0, Reg = 0, e = ValueVTs.size(); Value != e; ++Value) { +    unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVTs[Value]); +    MVT RegisterVT = RegVTs[Value]; +    for (unsigned i = 0; i != NumRegs; ++i) { +      assert(Reg < Regs.size() && "Mismatch in # registers expected"); +      unsigned TheReg = Regs[Reg++]; +      Ops.push_back(DAG.getRegister(TheReg, RegisterVT)); + +      if (TheReg == SP && Code == InlineAsm::Kind_Clobber) { +        // If we clobbered the stack pointer, MFI should know about it. +        assert(DAG.getMachineFunction().getFrameInfo().hasOpaqueSPAdjustment()); +      } +    } +  } +} + +void SelectionDAGBuilder::init(GCFunctionInfo *gfi, AliasAnalysis *aa, +                               const TargetLibraryInfo *li) { +  AA = aa; +  GFI = gfi; +  LibInfo = li; +  DL = &DAG.getDataLayout(); +  Context = DAG.getContext(); +  LPadToCallSiteMap.clear(); +} + +void SelectionDAGBuilder::clear() { +  NodeMap.clear(); +  UnusedArgNodeMap.clear(); +  PendingLoads.clear(); +  PendingExports.clear(); +  CurInst = nullptr; +  HasTailCall = false; +  SDNodeOrder = LowestSDNodeOrder; +  StatepointLowering.clear(); +} + +void SelectionDAGBuilder::clearDanglingDebugInfo() { +  DanglingDebugInfoMap.clear(); +} + +SDValue SelectionDAGBuilder::getRoot() { +  if (PendingLoads.empty()) +    return DAG.getRoot(); + +  if (PendingLoads.size() == 1) { +    SDValue Root = PendingLoads[0]; +    DAG.setRoot(Root); +    PendingLoads.clear(); +    return Root; +  } + +  // Otherwise, we have to make a token factor node. +  SDValue Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, +                             PendingLoads); +  PendingLoads.clear(); +  DAG.setRoot(Root); +  return Root; +} + +SDValue SelectionDAGBuilder::getControlRoot() { +  SDValue Root = DAG.getRoot(); + +  if (PendingExports.empty()) +    return Root; + +  // Turn all of the CopyToReg chains into one factored node. +  if (Root.getOpcode() != ISD::EntryToken) { +    unsigned i = 0, e = PendingExports.size(); +    for (; i != e; ++i) { +      assert(PendingExports[i].getNode()->getNumOperands() > 1); +      if (PendingExports[i].getNode()->getOperand(0) == Root) +        break;  // Don't add the root if we already indirectly depend on it. +    } + +    if (i == e) +      PendingExports.push_back(Root); +  } + +  Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, +                     PendingExports); +  PendingExports.clear(); +  DAG.setRoot(Root); +  return Root; +} + +void SelectionDAGBuilder::visit(const Instruction &I) { +  // Set up outgoing PHI node register values before emitting the terminator. +  if (isa<TerminatorInst>(&I)) { +    HandlePHINodesInSuccessorBlocks(I.getParent()); +  } + +  // Increase the SDNodeOrder if dealing with a non-debug instruction. +  if (!isa<DbgInfoIntrinsic>(I)) +    ++SDNodeOrder; + +  CurInst = &I; + +  visit(I.getOpcode(), I); + +  if (!isa<TerminatorInst>(&I) && !HasTailCall && +      !isStatepoint(&I)) // statepoints handle their exports internally +    CopyToExportRegsIfNeeded(&I); + +  CurInst = nullptr; +} + +void SelectionDAGBuilder::visitPHI(const PHINode &) { +  llvm_unreachable("SelectionDAGBuilder shouldn't visit PHI nodes!"); +} + +void SelectionDAGBuilder::visit(unsigned Opcode, const User &I) { +  // Note: this doesn't use InstVisitor, because it has to work with +  // ConstantExpr's in addition to instructions. +  switch (Opcode) { +  default: llvm_unreachable("Unknown instruction type encountered!"); +    // Build the switch statement using the Instruction.def file. +#define HANDLE_INST(NUM, OPCODE, CLASS) \ +    case Instruction::OPCODE: visit##OPCODE((const CLASS&)I); break; +#include "llvm/IR/Instruction.def" +  } +} + +// resolveDanglingDebugInfo - if we saw an earlier dbg_value referring to V, +// generate the debug data structures now that we've seen its definition. +void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V, +                                                   SDValue Val) { +  DanglingDebugInfo &DDI = DanglingDebugInfoMap[V]; +  if (DDI.getDI()) { +    const DbgValueInst *DI = DDI.getDI(); +    DebugLoc dl = DDI.getdl(); +    unsigned DbgSDNodeOrder = DDI.getSDNodeOrder(); +    DILocalVariable *Variable = DI->getVariable(); +    DIExpression *Expr = DI->getExpression(); +    assert(Variable->isValidLocationForIntrinsic(dl) && +           "Expected inlined-at fields to agree"); +    uint64_t Offset = DI->getOffset(); +    SDDbgValue *SDV; +    if (Val.getNode()) { +      if (!EmitFuncArgumentDbgValue(V, Variable, Expr, dl, Offset, false, +                                    Val)) { +        SDV = getDbgValue(Val, Variable, Expr, Offset, dl, DbgSDNodeOrder); +        DAG.AddDbgValue(SDV, Val.getNode(), false); +      } +    } else +      DEBUG(dbgs() << "Dropping debug info for " << *DI << "\n"); +    DanglingDebugInfoMap[V] = DanglingDebugInfo(); +  } +} + +/// getCopyFromRegs - If there was virtual register allocated for the value V +/// emit CopyFromReg of the specified type Ty. Return empty SDValue() otherwise. +SDValue SelectionDAGBuilder::getCopyFromRegs(const Value *V, Type *Ty) { +  DenseMap<const Value *, unsigned>::iterator It = FuncInfo.ValueMap.find(V); +  SDValue Result; + +  if (It != FuncInfo.ValueMap.end()) { +    unsigned InReg = It->second; +    bool IsABIRegCopy = +        V && ((isa<CallInst>(V) && +               !(static_cast<const CallInst *>(V))->isInlineAsm()) || +              isa<ReturnInst>(V)); + +    RegsForValue RFV(*DAG.getContext(), DAG.getTargetLoweringInfo(), +                     DAG.getDataLayout(), InReg, Ty, IsABIRegCopy); +    SDValue Chain = DAG.getEntryNode(); +    Result = RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, +                                 V); +    resolveDanglingDebugInfo(V, Result); +  } + +  return Result; +} + +/// getValue - Return an SDValue for the given Value. +SDValue SelectionDAGBuilder::getValue(const Value *V) { +  // If we already have an SDValue for this value, use it. It's important +  // to do this first, so that we don't create a CopyFromReg if we already +  // have a regular SDValue. +  SDValue &N = NodeMap[V]; +  if (N.getNode()) return N; + +  // If there's a virtual register allocated and initialized for this +  // value, use it. +  if (SDValue copyFromReg = getCopyFromRegs(V, V->getType())) +    return copyFromReg; + +  // Otherwise create a new SDValue and remember it. +  SDValue Val = getValueImpl(V); +  NodeMap[V] = Val; +  resolveDanglingDebugInfo(V, Val); +  return Val; +} + +// Return true if SDValue exists for the given Value +bool SelectionDAGBuilder::findValue(const Value *V) const { +  return (NodeMap.find(V) != NodeMap.end()) || +    (FuncInfo.ValueMap.find(V) != FuncInfo.ValueMap.end()); +} + +/// getNonRegisterValue - Return an SDValue for the given Value, but +/// don't look in FuncInfo.ValueMap for a virtual register. +SDValue SelectionDAGBuilder::getNonRegisterValue(const Value *V) { +  // If we already have an SDValue for this value, use it. +  SDValue &N = NodeMap[V]; +  if (N.getNode()) { +    if (isa<ConstantSDNode>(N) || isa<ConstantFPSDNode>(N)) { +      // Remove the debug location from the node as the node is about to be used +      // in a location which may differ from the original debug location.  This +      // is relevant to Constant and ConstantFP nodes because they can appear +      // as constant expressions inside PHI nodes. +      N->setDebugLoc(DebugLoc()); +    } +    return N; +  } + +  // Otherwise create a new SDValue and remember it. +  SDValue Val = getValueImpl(V); +  NodeMap[V] = Val; +  resolveDanglingDebugInfo(V, Val); +  return Val; +} + +/// getValueImpl - Helper function for getValue and getNonRegisterValue. +/// Create an SDValue for the given value. +SDValue SelectionDAGBuilder::getValueImpl(const Value *V) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); + +  if (const Constant *C = dyn_cast<Constant>(V)) { +    EVT VT = TLI.getValueType(DAG.getDataLayout(), V->getType(), true); + +    if (const ConstantInt *CI = dyn_cast<ConstantInt>(C)) +      return DAG.getConstant(*CI, getCurSDLoc(), VT); + +    if (const GlobalValue *GV = dyn_cast<GlobalValue>(C)) +      return DAG.getGlobalAddress(GV, getCurSDLoc(), VT); + +    if (isa<ConstantPointerNull>(C)) { +      unsigned AS = V->getType()->getPointerAddressSpace(); +      return DAG.getConstant(0, getCurSDLoc(), +                             TLI.getPointerTy(DAG.getDataLayout(), AS)); +    } + +    if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) +      return DAG.getConstantFP(*CFP, getCurSDLoc(), VT); + +    if (isa<UndefValue>(C) && !V->getType()->isAggregateType()) +      return DAG.getUNDEF(VT); + +    if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) { +      visit(CE->getOpcode(), *CE); +      SDValue N1 = NodeMap[V]; +      assert(N1.getNode() && "visit didn't populate the NodeMap!"); +      return N1; +    } + +    if (isa<ConstantStruct>(C) || isa<ConstantArray>(C)) { +      SmallVector<SDValue, 4> Constants; +      for (User::const_op_iterator OI = C->op_begin(), OE = C->op_end(); +           OI != OE; ++OI) { +        SDNode *Val = getValue(*OI).getNode(); +        // If the operand is an empty aggregate, there are no values. +        if (!Val) continue; +        // Add each leaf value from the operand to the Constants list +        // to form a flattened list of all the values. +        for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i) +          Constants.push_back(SDValue(Val, i)); +      } + +      return DAG.getMergeValues(Constants, getCurSDLoc()); +    } + +    if (const ConstantDataSequential *CDS = +          dyn_cast<ConstantDataSequential>(C)) { +      SmallVector<SDValue, 4> Ops; +      for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { +        SDNode *Val = getValue(CDS->getElementAsConstant(i)).getNode(); +        // Add each leaf value from the operand to the Constants list +        // to form a flattened list of all the values. +        for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i) +          Ops.push_back(SDValue(Val, i)); +      } + +      if (isa<ArrayType>(CDS->getType())) +        return DAG.getMergeValues(Ops, getCurSDLoc()); +      return NodeMap[V] = DAG.getBuildVector(VT, getCurSDLoc(), Ops); +    } + +    if (C->getType()->isStructTy() || C->getType()->isArrayTy()) { +      assert((isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) && +             "Unknown struct or array constant!"); + +      SmallVector<EVT, 4> ValueVTs; +      ComputeValueVTs(TLI, DAG.getDataLayout(), C->getType(), ValueVTs); +      unsigned NumElts = ValueVTs.size(); +      if (NumElts == 0) +        return SDValue(); // empty struct +      SmallVector<SDValue, 4> Constants(NumElts); +      for (unsigned i = 0; i != NumElts; ++i) { +        EVT EltVT = ValueVTs[i]; +        if (isa<UndefValue>(C)) +          Constants[i] = DAG.getUNDEF(EltVT); +        else if (EltVT.isFloatingPoint()) +          Constants[i] = DAG.getConstantFP(0, getCurSDLoc(), EltVT); +        else +          Constants[i] = DAG.getConstant(0, getCurSDLoc(), EltVT); +      } + +      return DAG.getMergeValues(Constants, getCurSDLoc()); +    } + +    if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) +      return DAG.getBlockAddress(BA, VT); + +    VectorType *VecTy = cast<VectorType>(V->getType()); +    unsigned NumElements = VecTy->getNumElements(); + +    // Now that we know the number and type of the elements, get that number of +    // elements into the Ops array based on what kind of constant it is. +    SmallVector<SDValue, 16> Ops; +    if (const ConstantVector *CV = dyn_cast<ConstantVector>(C)) { +      for (unsigned i = 0; i != NumElements; ++i) +        Ops.push_back(getValue(CV->getOperand(i))); +    } else { +      assert(isa<ConstantAggregateZero>(C) && "Unknown vector constant!"); +      EVT EltVT = +          TLI.getValueType(DAG.getDataLayout(), VecTy->getElementType()); + +      SDValue Op; +      if (EltVT.isFloatingPoint()) +        Op = DAG.getConstantFP(0, getCurSDLoc(), EltVT); +      else +        Op = DAG.getConstant(0, getCurSDLoc(), EltVT); +      Ops.assign(NumElements, Op); +    } + +    // Create a BUILD_VECTOR node. +    return NodeMap[V] = DAG.getBuildVector(VT, getCurSDLoc(), Ops); +  } + +  // If this is a static alloca, generate it as the frameindex instead of +  // computation. +  if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) { +    DenseMap<const AllocaInst*, int>::iterator SI = +      FuncInfo.StaticAllocaMap.find(AI); +    if (SI != FuncInfo.StaticAllocaMap.end()) +      return DAG.getFrameIndex(SI->second, +                               TLI.getFrameIndexTy(DAG.getDataLayout())); +  } + +  // If this is an instruction which fast-isel has deferred, select it now. +  if (const Instruction *Inst = dyn_cast<Instruction>(V)) { +    unsigned InReg = FuncInfo.InitializeRegForValue(Inst); +    bool IsABIRegCopy = +        V && ((isa<CallInst>(V) && +               !(static_cast<const CallInst *>(V))->isInlineAsm()) || +              isa<ReturnInst>(V)); + +    RegsForValue RFV(*DAG.getContext(), TLI, DAG.getDataLayout(), InReg, +                     Inst->getType(), IsABIRegCopy); +    SDValue Chain = DAG.getEntryNode(); +    return RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V); +  } + +  llvm_unreachable("Can't get register for value!"); +} + +void SelectionDAGBuilder::visitCatchPad(const CatchPadInst &I) { +  auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()); +  bool IsMSVCCXX = Pers == EHPersonality::MSVC_CXX; +  bool IsCoreCLR = Pers == EHPersonality::CoreCLR; +  MachineBasicBlock *CatchPadMBB = FuncInfo.MBB; +  // In MSVC C++ and CoreCLR, catchblocks are funclets and need prologues. +  if (IsMSVCCXX || IsCoreCLR) +    CatchPadMBB->setIsEHFuncletEntry(); + +  DAG.setRoot(DAG.getNode(ISD::CATCHPAD, getCurSDLoc(), MVT::Other, getControlRoot())); +} + +void SelectionDAGBuilder::visitCatchRet(const CatchReturnInst &I) { +  // Update machine-CFG edge. +  MachineBasicBlock *TargetMBB = FuncInfo.MBBMap[I.getSuccessor()]; +  FuncInfo.MBB->addSuccessor(TargetMBB); + +  auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()); +  bool IsSEH = isAsynchronousEHPersonality(Pers); +  if (IsSEH) { +    // If this is not a fall-through branch or optimizations are switched off, +    // emit the branch. +    if (TargetMBB != NextBlock(FuncInfo.MBB) || +        TM.getOptLevel() == CodeGenOpt::None) +      DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other, +                              getControlRoot(), DAG.getBasicBlock(TargetMBB))); +    return; +  } + +  // Figure out the funclet membership for the catchret's successor. +  // This will be used by the FuncletLayout pass to determine how to order the +  // BB's. +  // A 'catchret' returns to the outer scope's color. +  Value *ParentPad = I.getCatchSwitchParentPad(); +  const BasicBlock *SuccessorColor; +  if (isa<ConstantTokenNone>(ParentPad)) +    SuccessorColor = &FuncInfo.Fn->getEntryBlock(); +  else +    SuccessorColor = cast<Instruction>(ParentPad)->getParent(); +  assert(SuccessorColor && "No parent funclet for catchret!"); +  MachineBasicBlock *SuccessorColorMBB = FuncInfo.MBBMap[SuccessorColor]; +  assert(SuccessorColorMBB && "No MBB for SuccessorColor!"); + +  // Create the terminator node. +  SDValue Ret = DAG.getNode(ISD::CATCHRET, getCurSDLoc(), MVT::Other, +                            getControlRoot(), DAG.getBasicBlock(TargetMBB), +                            DAG.getBasicBlock(SuccessorColorMBB)); +  DAG.setRoot(Ret); +} + +void SelectionDAGBuilder::visitCleanupPad(const CleanupPadInst &CPI) { +  // Don't emit any special code for the cleanuppad instruction. It just marks +  // the start of a funclet. +  FuncInfo.MBB->setIsEHFuncletEntry(); +  FuncInfo.MBB->setIsCleanupFuncletEntry(); +} + +/// When an invoke or a cleanupret unwinds to the next EH pad, there are +/// many places it could ultimately go. In the IR, we have a single unwind +/// destination, but in the machine CFG, we enumerate all the possible blocks. +/// This function skips over imaginary basic blocks that hold catchswitch +/// instructions, and finds all the "real" machine +/// basic block destinations. As those destinations may not be successors of +/// EHPadBB, here we also calculate the edge probability to those destinations. +/// The passed-in Prob is the edge probability to EHPadBB. +static void findUnwindDestinations( +    FunctionLoweringInfo &FuncInfo, const BasicBlock *EHPadBB, +    BranchProbability Prob, +    SmallVectorImpl<std::pair<MachineBasicBlock *, BranchProbability>> +        &UnwindDests) { +  EHPersonality Personality = +    classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()); +  bool IsMSVCCXX = Personality == EHPersonality::MSVC_CXX; +  bool IsCoreCLR = Personality == EHPersonality::CoreCLR; + +  while (EHPadBB) { +    const Instruction *Pad = EHPadBB->getFirstNonPHI(); +    BasicBlock *NewEHPadBB = nullptr; +    if (isa<LandingPadInst>(Pad)) { +      // Stop on landingpads. They are not funclets. +      UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob); +      break; +    } else if (isa<CleanupPadInst>(Pad)) { +      // Stop on cleanup pads. Cleanups are always funclet entries for all known +      // personalities. +      UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob); +      UnwindDests.back().first->setIsEHFuncletEntry(); +      break; +    } else if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(Pad)) { +      // Add the catchpad handlers to the possible destinations. +      for (const BasicBlock *CatchPadBB : CatchSwitch->handlers()) { +        UnwindDests.emplace_back(FuncInfo.MBBMap[CatchPadBB], Prob); +        // For MSVC++ and the CLR, catchblocks are funclets and need prologues. +        if (IsMSVCCXX || IsCoreCLR) +          UnwindDests.back().first->setIsEHFuncletEntry(); +      } +      NewEHPadBB = CatchSwitch->getUnwindDest(); +    } else { +      continue; +    } + +    BranchProbabilityInfo *BPI = FuncInfo.BPI; +    if (BPI && NewEHPadBB) +      Prob *= BPI->getEdgeProbability(EHPadBB, NewEHPadBB); +    EHPadBB = NewEHPadBB; +  } +} + +void SelectionDAGBuilder::visitCleanupRet(const CleanupReturnInst &I) { +  // Update successor info. +  SmallVector<std::pair<MachineBasicBlock *, BranchProbability>, 1> UnwindDests; +  auto UnwindDest = I.getUnwindDest(); +  BranchProbabilityInfo *BPI = FuncInfo.BPI; +  BranchProbability UnwindDestProb = +      (BPI && UnwindDest) +          ? BPI->getEdgeProbability(FuncInfo.MBB->getBasicBlock(), UnwindDest) +          : BranchProbability::getZero(); +  findUnwindDestinations(FuncInfo, UnwindDest, UnwindDestProb, UnwindDests); +  for (auto &UnwindDest : UnwindDests) { +    UnwindDest.first->setIsEHPad(); +    addSuccessorWithProb(FuncInfo.MBB, UnwindDest.first, UnwindDest.second); +  } +  FuncInfo.MBB->normalizeSuccProbs(); + +  // Create the terminator node. +  SDValue Ret = +      DAG.getNode(ISD::CLEANUPRET, getCurSDLoc(), MVT::Other, getControlRoot()); +  DAG.setRoot(Ret); +} + +void SelectionDAGBuilder::visitCatchSwitch(const CatchSwitchInst &CSI) { +  report_fatal_error("visitCatchSwitch not yet implemented!"); +} + +void SelectionDAGBuilder::visitRet(const ReturnInst &I) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  auto &DL = DAG.getDataLayout(); +  SDValue Chain = getControlRoot(); +  SmallVector<ISD::OutputArg, 8> Outs; +  SmallVector<SDValue, 8> OutVals; + +  // Calls to @llvm.experimental.deoptimize don't generate a return value, so +  // lower +  // +  //   %val = call <ty> @llvm.experimental.deoptimize() +  //   ret <ty> %val +  // +  // differently. +  if (I.getParent()->getTerminatingDeoptimizeCall()) { +    LowerDeoptimizingReturn(); +    return; +  } + +  if (!FuncInfo.CanLowerReturn) { +    unsigned DemoteReg = FuncInfo.DemoteRegister; +    const Function *F = I.getParent()->getParent(); + +    // Emit a store of the return value through the virtual register. +    // Leave Outs empty so that LowerReturn won't try to load return +    // registers the usual way. +    SmallVector<EVT, 1> PtrValueVTs; +    ComputeValueVTs(TLI, DL, PointerType::getUnqual(F->getReturnType()), +                    PtrValueVTs); + +    SDValue RetPtr = DAG.getCopyFromReg(DAG.getEntryNode(), getCurSDLoc(), +                                        DemoteReg, PtrValueVTs[0]); +    SDValue RetOp = getValue(I.getOperand(0)); + +    SmallVector<EVT, 4> ValueVTs; +    SmallVector<uint64_t, 4> Offsets; +    ComputeValueVTs(TLI, DL, I.getOperand(0)->getType(), ValueVTs, &Offsets); +    unsigned NumValues = ValueVTs.size(); + +    // An aggregate return value cannot wrap around the address space, so +    // offsets to its parts don't wrap either. +    SDNodeFlags Flags; +    Flags.setNoUnsignedWrap(true); + +    SmallVector<SDValue, 4> Chains(NumValues); +    for (unsigned i = 0; i != NumValues; ++i) { +      SDValue Add = DAG.getNode(ISD::ADD, getCurSDLoc(), +                                RetPtr.getValueType(), RetPtr, +                                DAG.getIntPtrConstant(Offsets[i], +                                                      getCurSDLoc()), +                                Flags); +      Chains[i] = DAG.getStore(Chain, getCurSDLoc(), +                               SDValue(RetOp.getNode(), RetOp.getResNo() + i), +                               // FIXME: better loc info would be nice. +                               Add, MachinePointerInfo()); +    } + +    Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), +                        MVT::Other, Chains); +  } else if (I.getNumOperands() != 0) { +    SmallVector<EVT, 4> ValueVTs; +    ComputeValueVTs(TLI, DL, I.getOperand(0)->getType(), ValueVTs); +    unsigned NumValues = ValueVTs.size(); +    if (NumValues) { +      SDValue RetOp = getValue(I.getOperand(0)); + +      const Function *F = I.getParent()->getParent(); + +      ISD::NodeType ExtendKind = ISD::ANY_EXTEND; +      if (F->getAttributes().hasAttribute(AttributeList::ReturnIndex, +                                          Attribute::SExt)) +        ExtendKind = ISD::SIGN_EXTEND; +      else if (F->getAttributes().hasAttribute(AttributeList::ReturnIndex, +                                               Attribute::ZExt)) +        ExtendKind = ISD::ZERO_EXTEND; + +      LLVMContext &Context = F->getContext(); +      bool RetInReg = F->getAttributes().hasAttribute( +          AttributeList::ReturnIndex, Attribute::InReg); + +      for (unsigned j = 0; j != NumValues; ++j) { +        EVT VT = ValueVTs[j]; + +        if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger()) +          VT = TLI.getTypeForExtReturn(Context, VT, ExtendKind); + +        unsigned NumParts = TLI.getNumRegistersForCallingConv(Context, VT); +        MVT PartVT = TLI.getRegisterTypeForCallingConv(Context, VT); +        SmallVector<SDValue, 4> Parts(NumParts); +        getCopyToParts(DAG, getCurSDLoc(), +                       SDValue(RetOp.getNode(), RetOp.getResNo() + j), +                       &Parts[0], NumParts, PartVT, &I, ExtendKind, true); + +        // 'inreg' on function refers to return value +        ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy(); +        if (RetInReg) +          Flags.setInReg(); + +        // Propagate extension type if any +        if (ExtendKind == ISD::SIGN_EXTEND) +          Flags.setSExt(); +        else if (ExtendKind == ISD::ZERO_EXTEND) +          Flags.setZExt(); + +        for (unsigned i = 0; i < NumParts; ++i) { +          Outs.push_back(ISD::OutputArg(Flags, Parts[i].getValueType(), +                                        VT, /*isfixed=*/true, 0, 0)); +          OutVals.push_back(Parts[i]); +        } +      } +    } +  } + +  // Push in swifterror virtual register as the last element of Outs. This makes +  // sure swifterror virtual register will be returned in the swifterror +  // physical register. +  const Function *F = I.getParent()->getParent(); +  if (TLI.supportSwiftError() && +      F->getAttributes().hasAttrSomewhere(Attribute::SwiftError)) { +    assert(FuncInfo.SwiftErrorArg && "Need a swift error argument"); +    ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy(); +    Flags.setSwiftError(); +    Outs.push_back(ISD::OutputArg(Flags, EVT(TLI.getPointerTy(DL)) /*vt*/, +                                  EVT(TLI.getPointerTy(DL)) /*argvt*/, +                                  true /*isfixed*/, 1 /*origidx*/, +                                  0 /*partOffs*/)); +    // Create SDNode for the swifterror virtual register. +    OutVals.push_back( +        DAG.getRegister(FuncInfo.getOrCreateSwiftErrorVRegUseAt( +                            &I, FuncInfo.MBB, FuncInfo.SwiftErrorArg).first, +                        EVT(TLI.getPointerTy(DL)))); +  } + +  bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg(); +  CallingConv::ID CallConv = +    DAG.getMachineFunction().getFunction()->getCallingConv(); +  Chain = DAG.getTargetLoweringInfo().LowerReturn( +      Chain, CallConv, isVarArg, Outs, OutVals, getCurSDLoc(), DAG); + +  // Verify that the target's LowerReturn behaved as expected. +  assert(Chain.getNode() && Chain.getValueType() == MVT::Other && +         "LowerReturn didn't return a valid chain!"); + +  // Update the DAG with the new chain value resulting from return lowering. +  DAG.setRoot(Chain); +} + +/// CopyToExportRegsIfNeeded - If the given value has virtual registers +/// created for it, emit nodes to copy the value into the virtual +/// registers. +void SelectionDAGBuilder::CopyToExportRegsIfNeeded(const Value *V) { +  // Skip empty types +  if (V->getType()->isEmptyTy()) +    return; + +  DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V); +  if (VMI != FuncInfo.ValueMap.end()) { +    assert(!V->use_empty() && "Unused value assigned virtual registers!"); +    CopyValueToVirtualRegister(V, VMI->second); +  } +} + +/// ExportFromCurrentBlock - If this condition isn't known to be exported from +/// the current basic block, add it to ValueMap now so that we'll get a +/// CopyTo/FromReg. +void SelectionDAGBuilder::ExportFromCurrentBlock(const Value *V) { +  // No need to export constants. +  if (!isa<Instruction>(V) && !isa<Argument>(V)) return; + +  // Already exported? +  if (FuncInfo.isExportedInst(V)) return; + +  unsigned Reg = FuncInfo.InitializeRegForValue(V); +  CopyValueToVirtualRegister(V, Reg); +} + +bool SelectionDAGBuilder::isExportableFromCurrentBlock(const Value *V, +                                                     const BasicBlock *FromBB) { +  // The operands of the setcc have to be in this block.  We don't know +  // how to export them from some other block. +  if (const Instruction *VI = dyn_cast<Instruction>(V)) { +    // Can export from current BB. +    if (VI->getParent() == FromBB) +      return true; + +    // Is already exported, noop. +    return FuncInfo.isExportedInst(V); +  } + +  // If this is an argument, we can export it if the BB is the entry block or +  // if it is already exported. +  if (isa<Argument>(V)) { +    if (FromBB == &FromBB->getParent()->getEntryBlock()) +      return true; + +    // Otherwise, can only export this if it is already exported. +    return FuncInfo.isExportedInst(V); +  } + +  // Otherwise, constants can always be exported. +  return true; +} + +/// Return branch probability calculated by BranchProbabilityInfo for IR blocks. +BranchProbability +SelectionDAGBuilder::getEdgeProbability(const MachineBasicBlock *Src, +                                        const MachineBasicBlock *Dst) const { +  BranchProbabilityInfo *BPI = FuncInfo.BPI; +  const BasicBlock *SrcBB = Src->getBasicBlock(); +  const BasicBlock *DstBB = Dst->getBasicBlock(); +  if (!BPI) { +    // If BPI is not available, set the default probability as 1 / N, where N is +    // the number of successors. +    auto SuccSize = std::max<uint32_t>( +        std::distance(succ_begin(SrcBB), succ_end(SrcBB)), 1); +    return BranchProbability(1, SuccSize); +  } +  return BPI->getEdgeProbability(SrcBB, DstBB); +} + +void SelectionDAGBuilder::addSuccessorWithProb(MachineBasicBlock *Src, +                                               MachineBasicBlock *Dst, +                                               BranchProbability Prob) { +  if (!FuncInfo.BPI) +    Src->addSuccessorWithoutProb(Dst); +  else { +    if (Prob.isUnknown()) +      Prob = getEdgeProbability(Src, Dst); +    Src->addSuccessor(Dst, Prob); +  } +} + +static bool InBlock(const Value *V, const BasicBlock *BB) { +  if (const Instruction *I = dyn_cast<Instruction>(V)) +    return I->getParent() == BB; +  return true; +} + +/// EmitBranchForMergedCondition - Helper method for FindMergedConditions. +/// This function emits a branch and is used at the leaves of an OR or an +/// AND operator tree. +/// +void +SelectionDAGBuilder::EmitBranchForMergedCondition(const Value *Cond, +                                                  MachineBasicBlock *TBB, +                                                  MachineBasicBlock *FBB, +                                                  MachineBasicBlock *CurBB, +                                                  MachineBasicBlock *SwitchBB, +                                                  BranchProbability TProb, +                                                  BranchProbability FProb, +                                                  bool InvertCond) { +  const BasicBlock *BB = CurBB->getBasicBlock(); + +  // If the leaf of the tree is a comparison, merge the condition into +  // the caseblock. +  if (const CmpInst *BOp = dyn_cast<CmpInst>(Cond)) { +    // The operands of the cmp have to be in this block.  We don't know +    // how to export them from some other block.  If this is the first block +    // of the sequence, no exporting is needed. +    if (CurBB == SwitchBB || +        (isExportableFromCurrentBlock(BOp->getOperand(0), BB) && +         isExportableFromCurrentBlock(BOp->getOperand(1), BB))) { +      ISD::CondCode Condition; +      if (const ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) { +        ICmpInst::Predicate Pred = +            InvertCond ? IC->getInversePredicate() : IC->getPredicate(); +        Condition = getICmpCondCode(Pred); +      } else { +        const FCmpInst *FC = cast<FCmpInst>(Cond); +        FCmpInst::Predicate Pred = +            InvertCond ? FC->getInversePredicate() : FC->getPredicate(); +        Condition = getFCmpCondCode(Pred); +        if (TM.Options.NoNaNsFPMath) +          Condition = getFCmpCodeWithoutNaN(Condition); +      } + +      CaseBlock CB(Condition, BOp->getOperand(0), BOp->getOperand(1), nullptr, +                   TBB, FBB, CurBB, TProb, FProb); +      SwitchCases.push_back(CB); +      return; +    } +  } + +  // Create a CaseBlock record representing this branch. +  ISD::CondCode Opc = InvertCond ? ISD::SETNE : ISD::SETEQ; +  CaseBlock CB(Opc, Cond, ConstantInt::getTrue(*DAG.getContext()), +               nullptr, TBB, FBB, CurBB, TProb, FProb); +  SwitchCases.push_back(CB); +} + +/// FindMergedConditions - If Cond is an expression like +void SelectionDAGBuilder::FindMergedConditions(const Value *Cond, +                                               MachineBasicBlock *TBB, +                                               MachineBasicBlock *FBB, +                                               MachineBasicBlock *CurBB, +                                               MachineBasicBlock *SwitchBB, +                                               Instruction::BinaryOps Opc, +                                               BranchProbability TProb, +                                               BranchProbability FProb, +                                               bool InvertCond) { +  // Skip over not part of the tree and remember to invert op and operands at +  // next level. +  if (BinaryOperator::isNot(Cond) && Cond->hasOneUse()) { +    const Value *CondOp = BinaryOperator::getNotArgument(Cond); +    if (InBlock(CondOp, CurBB->getBasicBlock())) { +      FindMergedConditions(CondOp, TBB, FBB, CurBB, SwitchBB, Opc, TProb, FProb, +                           !InvertCond); +      return; +    } +  } + +  const Instruction *BOp = dyn_cast<Instruction>(Cond); +  // Compute the effective opcode for Cond, taking into account whether it needs +  // to be inverted, e.g. +  //   and (not (or A, B)), C +  // gets lowered as +  //   and (and (not A, not B), C) +  unsigned BOpc = 0; +  if (BOp) { +    BOpc = BOp->getOpcode(); +    if (InvertCond) { +      if (BOpc == Instruction::And) +        BOpc = Instruction::Or; +      else if (BOpc == Instruction::Or) +        BOpc = Instruction::And; +    } +  } + +  // If this node is not part of the or/and tree, emit it as a branch. +  if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) || +      BOpc != Opc || !BOp->hasOneUse() || +      BOp->getParent() != CurBB->getBasicBlock() || +      !InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) || +      !InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) { +    EmitBranchForMergedCondition(Cond, TBB, FBB, CurBB, SwitchBB, +                                 TProb, FProb, InvertCond); +    return; +  } + +  //  Create TmpBB after CurBB. +  MachineFunction::iterator BBI(CurBB); +  MachineFunction &MF = DAG.getMachineFunction(); +  MachineBasicBlock *TmpBB = MF.CreateMachineBasicBlock(CurBB->getBasicBlock()); +  CurBB->getParent()->insert(++BBI, TmpBB); + +  if (Opc == Instruction::Or) { +    // Codegen X | Y as: +    // BB1: +    //   jmp_if_X TBB +    //   jmp TmpBB +    // TmpBB: +    //   jmp_if_Y TBB +    //   jmp FBB +    // + +    // We have flexibility in setting Prob for BB1 and Prob for TmpBB. +    // The requirement is that +    //   TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB) +    //     = TrueProb for original BB. +    // Assuming the original probabilities are A and B, one choice is to set +    // BB1's probabilities to A/2 and A/2+B, and set TmpBB's probabilities to +    // A/(1+B) and 2B/(1+B). This choice assumes that +    //   TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB. +    // Another choice is to assume TrueProb for BB1 equals to TrueProb for +    // TmpBB, but the math is more complicated. + +    auto NewTrueProb = TProb / 2; +    auto NewFalseProb = TProb / 2 + FProb; +    // Emit the LHS condition. +    FindMergedConditions(BOp->getOperand(0), TBB, TmpBB, CurBB, SwitchBB, Opc, +                         NewTrueProb, NewFalseProb, InvertCond); + +    // Normalize A/2 and B to get A/(1+B) and 2B/(1+B). +    SmallVector<BranchProbability, 2> Probs{TProb / 2, FProb}; +    BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end()); +    // Emit the RHS condition into TmpBB. +    FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc, +                         Probs[0], Probs[1], InvertCond); +  } else { +    assert(Opc == Instruction::And && "Unknown merge op!"); +    // Codegen X & Y as: +    // BB1: +    //   jmp_if_X TmpBB +    //   jmp FBB +    // TmpBB: +    //   jmp_if_Y TBB +    //   jmp FBB +    // +    //  This requires creation of TmpBB after CurBB. + +    // We have flexibility in setting Prob for BB1 and Prob for TmpBB. +    // The requirement is that +    //   FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB) +    //     = FalseProb for original BB. +    // Assuming the original probabilities are A and B, one choice is to set +    // BB1's probabilities to A+B/2 and B/2, and set TmpBB's probabilities to +    // 2A/(1+A) and B/(1+A). This choice assumes that FalseProb for BB1 == +    // TrueProb for BB1 * FalseProb for TmpBB. + +    auto NewTrueProb = TProb + FProb / 2; +    auto NewFalseProb = FProb / 2; +    // Emit the LHS condition. +    FindMergedConditions(BOp->getOperand(0), TmpBB, FBB, CurBB, SwitchBB, Opc, +                         NewTrueProb, NewFalseProb, InvertCond); + +    // Normalize A and B/2 to get 2A/(1+A) and B/(1+A). +    SmallVector<BranchProbability, 2> Probs{TProb, FProb / 2}; +    BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end()); +    // Emit the RHS condition into TmpBB. +    FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc, +                         Probs[0], Probs[1], InvertCond); +  } +} + +/// If the set of cases should be emitted as a series of branches, return true. +/// If we should emit this as a bunch of and/or'd together conditions, return +/// false. +bool +SelectionDAGBuilder::ShouldEmitAsBranches(const std::vector<CaseBlock> &Cases) { +  if (Cases.size() != 2) return true; + +  // If this is two comparisons of the same values or'd or and'd together, they +  // will get folded into a single comparison, so don't emit two blocks. +  if ((Cases[0].CmpLHS == Cases[1].CmpLHS && +       Cases[0].CmpRHS == Cases[1].CmpRHS) || +      (Cases[0].CmpRHS == Cases[1].CmpLHS && +       Cases[0].CmpLHS == Cases[1].CmpRHS)) { +    return false; +  } + +  // Handle: (X != null) | (Y != null) --> (X|Y) != 0 +  // Handle: (X == null) & (Y == null) --> (X|Y) == 0 +  if (Cases[0].CmpRHS == Cases[1].CmpRHS && +      Cases[0].CC == Cases[1].CC && +      isa<Constant>(Cases[0].CmpRHS) && +      cast<Constant>(Cases[0].CmpRHS)->isNullValue()) { +    if (Cases[0].CC == ISD::SETEQ && Cases[0].TrueBB == Cases[1].ThisBB) +      return false; +    if (Cases[0].CC == ISD::SETNE && Cases[0].FalseBB == Cases[1].ThisBB) +      return false; +  } + +  return true; +} + +void SelectionDAGBuilder::visitBr(const BranchInst &I) { +  MachineBasicBlock *BrMBB = FuncInfo.MBB; + +  // Update machine-CFG edges. +  MachineBasicBlock *Succ0MBB = FuncInfo.MBBMap[I.getSuccessor(0)]; + +  if (I.isUnconditional()) { +    // Update machine-CFG edges. +    BrMBB->addSuccessor(Succ0MBB); + +    // If this is not a fall-through branch or optimizations are switched off, +    // emit the branch. +    if (Succ0MBB != NextBlock(BrMBB) || TM.getOptLevel() == CodeGenOpt::None) +      DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), +                              MVT::Other, getControlRoot(), +                              DAG.getBasicBlock(Succ0MBB))); + +    return; +  } + +  // If this condition is one of the special cases we handle, do special stuff +  // now. +  const Value *CondVal = I.getCondition(); +  MachineBasicBlock *Succ1MBB = FuncInfo.MBBMap[I.getSuccessor(1)]; + +  // If this is a series of conditions that are or'd or and'd together, emit +  // this as a sequence of branches instead of setcc's with and/or operations. +  // As long as jumps are not expensive, this should improve performance. +  // For example, instead of something like: +  //     cmp A, B +  //     C = seteq +  //     cmp D, E +  //     F = setle +  //     or C, F +  //     jnz foo +  // Emit: +  //     cmp A, B +  //     je foo +  //     cmp D, E +  //     jle foo +  // +  if (const BinaryOperator *BOp = dyn_cast<BinaryOperator>(CondVal)) { +    Instruction::BinaryOps Opcode = BOp->getOpcode(); +    if (!DAG.getTargetLoweringInfo().isJumpExpensive() && BOp->hasOneUse() && +        !I.getMetadata(LLVMContext::MD_unpredictable) && +        (Opcode == Instruction::And || Opcode == Instruction::Or)) { +      FindMergedConditions(BOp, Succ0MBB, Succ1MBB, BrMBB, BrMBB, +                           Opcode, +                           getEdgeProbability(BrMBB, Succ0MBB), +                           getEdgeProbability(BrMBB, Succ1MBB), +                           /*InvertCond=*/false); +      // If the compares in later blocks need to use values not currently +      // exported from this block, export them now.  This block should always +      // be the first entry. +      assert(SwitchCases[0].ThisBB == BrMBB && "Unexpected lowering!"); + +      // Allow some cases to be rejected. +      if (ShouldEmitAsBranches(SwitchCases)) { +        for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) { +          ExportFromCurrentBlock(SwitchCases[i].CmpLHS); +          ExportFromCurrentBlock(SwitchCases[i].CmpRHS); +        } + +        // Emit the branch for this block. +        visitSwitchCase(SwitchCases[0], BrMBB); +        SwitchCases.erase(SwitchCases.begin()); +        return; +      } + +      // Okay, we decided not to do this, remove any inserted MBB's and clear +      // SwitchCases. +      for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) +        FuncInfo.MF->erase(SwitchCases[i].ThisBB); + +      SwitchCases.clear(); +    } +  } + +  // Create a CaseBlock record representing this branch. +  CaseBlock CB(ISD::SETEQ, CondVal, ConstantInt::getTrue(*DAG.getContext()), +               nullptr, Succ0MBB, Succ1MBB, BrMBB); + +  // Use visitSwitchCase to actually insert the fast branch sequence for this +  // cond branch. +  visitSwitchCase(CB, BrMBB); +} + +/// visitSwitchCase - Emits the necessary code to represent a single node in +/// the binary search tree resulting from lowering a switch instruction. +void SelectionDAGBuilder::visitSwitchCase(CaseBlock &CB, +                                          MachineBasicBlock *SwitchBB) { +  SDValue Cond; +  SDValue CondLHS = getValue(CB.CmpLHS); +  SDLoc dl = getCurSDLoc(); + +  // Build the setcc now. +  if (!CB.CmpMHS) { +    // Fold "(X == true)" to X and "(X == false)" to !X to +    // handle common cases produced by branch lowering. +    if (CB.CmpRHS == ConstantInt::getTrue(*DAG.getContext()) && +        CB.CC == ISD::SETEQ) +      Cond = CondLHS; +    else if (CB.CmpRHS == ConstantInt::getFalse(*DAG.getContext()) && +             CB.CC == ISD::SETEQ) { +      SDValue True = DAG.getConstant(1, dl, CondLHS.getValueType()); +      Cond = DAG.getNode(ISD::XOR, dl, CondLHS.getValueType(), CondLHS, True); +    } else +      Cond = DAG.getSetCC(dl, MVT::i1, CondLHS, getValue(CB.CmpRHS), CB.CC); +  } else { +    assert(CB.CC == ISD::SETLE && "Can handle only LE ranges now"); + +    const APInt& Low = cast<ConstantInt>(CB.CmpLHS)->getValue(); +    const APInt& High = cast<ConstantInt>(CB.CmpRHS)->getValue(); + +    SDValue CmpOp = getValue(CB.CmpMHS); +    EVT VT = CmpOp.getValueType(); + +    if (cast<ConstantInt>(CB.CmpLHS)->isMinValue(true)) { +      Cond = DAG.getSetCC(dl, MVT::i1, CmpOp, DAG.getConstant(High, dl, VT), +                          ISD::SETLE); +    } else { +      SDValue SUB = DAG.getNode(ISD::SUB, dl, +                                VT, CmpOp, DAG.getConstant(Low, dl, VT)); +      Cond = DAG.getSetCC(dl, MVT::i1, SUB, +                          DAG.getConstant(High-Low, dl, VT), ISD::SETULE); +    } +  } + +  // Update successor info +  addSuccessorWithProb(SwitchBB, CB.TrueBB, CB.TrueProb); +  // TrueBB and FalseBB are always different unless the incoming IR is +  // degenerate. This only happens when running llc on weird IR. +  if (CB.TrueBB != CB.FalseBB) +    addSuccessorWithProb(SwitchBB, CB.FalseBB, CB.FalseProb); +  SwitchBB->normalizeSuccProbs(); + +  // If the lhs block is the next block, invert the condition so that we can +  // fall through to the lhs instead of the rhs block. +  if (CB.TrueBB == NextBlock(SwitchBB)) { +    std::swap(CB.TrueBB, CB.FalseBB); +    SDValue True = DAG.getConstant(1, dl, Cond.getValueType()); +    Cond = DAG.getNode(ISD::XOR, dl, Cond.getValueType(), Cond, True); +  } + +  SDValue BrCond = DAG.getNode(ISD::BRCOND, dl, +                               MVT::Other, getControlRoot(), Cond, +                               DAG.getBasicBlock(CB.TrueBB)); + +  // Insert the false branch. Do this even if it's a fall through branch, +  // this makes it easier to do DAG optimizations which require inverting +  // the branch condition. +  BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond, +                       DAG.getBasicBlock(CB.FalseBB)); + +  DAG.setRoot(BrCond); +} + +/// visitJumpTable - Emit JumpTable node in the current MBB +void SelectionDAGBuilder::visitJumpTable(JumpTable &JT) { +  // Emit the code for the jump table +  assert(JT.Reg != -1U && "Should lower JT Header first!"); +  EVT PTy = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout()); +  SDValue Index = DAG.getCopyFromReg(getControlRoot(), getCurSDLoc(), +                                     JT.Reg, PTy); +  SDValue Table = DAG.getJumpTable(JT.JTI, PTy); +  SDValue BrJumpTable = DAG.getNode(ISD::BR_JT, getCurSDLoc(), +                                    MVT::Other, Index.getValue(1), +                                    Table, Index); +  DAG.setRoot(BrJumpTable); +} + +/// visitJumpTableHeader - This function emits necessary code to produce index +/// in the JumpTable from switch case. +void SelectionDAGBuilder::visitJumpTableHeader(JumpTable &JT, +                                               JumpTableHeader &JTH, +                                               MachineBasicBlock *SwitchBB) { +  SDLoc dl = getCurSDLoc(); + +  // Subtract the lowest switch case value from the value being switched on and +  // conditional branch to default mbb if the result is greater than the +  // difference between smallest and largest cases. +  SDValue SwitchOp = getValue(JTH.SValue); +  EVT VT = SwitchOp.getValueType(); +  SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp, +                            DAG.getConstant(JTH.First, dl, VT)); + +  // The SDNode we just created, which holds the value being switched on minus +  // the smallest case value, needs to be copied to a virtual register so it +  // can be used as an index into the jump table in a subsequent basic block. +  // This value may be smaller or larger than the target's pointer type, and +  // therefore require extension or truncating. +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SwitchOp = DAG.getZExtOrTrunc(Sub, dl, TLI.getPointerTy(DAG.getDataLayout())); + +  unsigned JumpTableReg = +      FuncInfo.CreateReg(TLI.getPointerTy(DAG.getDataLayout())); +  SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl, +                                    JumpTableReg, SwitchOp); +  JT.Reg = JumpTableReg; + +  // Emit the range check for the jump table, and branch to the default block +  // for the switch statement if the value being switched on exceeds the largest +  // case in the switch. +  SDValue CMP = DAG.getSetCC( +      dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), +                                 Sub.getValueType()), +      Sub, DAG.getConstant(JTH.Last - JTH.First, dl, VT), ISD::SETUGT); + +  SDValue BrCond = DAG.getNode(ISD::BRCOND, dl, +                               MVT::Other, CopyTo, CMP, +                               DAG.getBasicBlock(JT.Default)); + +  // Avoid emitting unnecessary branches to the next block. +  if (JT.MBB != NextBlock(SwitchBB)) +    BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond, +                         DAG.getBasicBlock(JT.MBB)); + +  DAG.setRoot(BrCond); +} + +/// Create a LOAD_STACK_GUARD node, and let it carry the target specific global +/// variable if there exists one. +static SDValue getLoadStackGuard(SelectionDAG &DAG, const SDLoc &DL, +                                 SDValue &Chain) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); +  MachineFunction &MF = DAG.getMachineFunction(); +  Value *Global = TLI.getSDagStackGuard(*MF.getFunction()->getParent()); +  MachineSDNode *Node = +      DAG.getMachineNode(TargetOpcode::LOAD_STACK_GUARD, DL, PtrTy, Chain); +  if (Global) { +    MachinePointerInfo MPInfo(Global); +    MachineInstr::mmo_iterator MemRefs = MF.allocateMemRefsArray(1); +    auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant | +                 MachineMemOperand::MODereferenceable; +    *MemRefs = MF.getMachineMemOperand(MPInfo, Flags, PtrTy.getSizeInBits() / 8, +                                       DAG.getEVTAlignment(PtrTy)); +    Node->setMemRefs(MemRefs, MemRefs + 1); +  } +  return SDValue(Node, 0); +} + +/// Codegen a new tail for a stack protector check ParentMBB which has had its +/// tail spliced into a stack protector check success bb. +/// +/// For a high level explanation of how this fits into the stack protector +/// generation see the comment on the declaration of class +/// StackProtectorDescriptor. +void SelectionDAGBuilder::visitSPDescriptorParent(StackProtectorDescriptor &SPD, +                                                  MachineBasicBlock *ParentBB) { + +  // First create the loads to the guard/stack slot for the comparison. +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); + +  MachineFrameInfo &MFI = ParentBB->getParent()->getFrameInfo(); +  int FI = MFI.getStackProtectorIndex(); + +  SDValue Guard; +  SDLoc dl = getCurSDLoc(); +  SDValue StackSlotPtr = DAG.getFrameIndex(FI, PtrTy); +  const Module &M = *ParentBB->getParent()->getFunction()->getParent(); +  unsigned Align = DL->getPrefTypeAlignment(Type::getInt8PtrTy(M.getContext())); + +  // Generate code to load the content of the guard slot. +  SDValue StackSlot = DAG.getLoad( +      PtrTy, dl, DAG.getEntryNode(), StackSlotPtr, +      MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI), Align, +      MachineMemOperand::MOVolatile); + +  // Retrieve guard check function, nullptr if instrumentation is inlined. +  if (const Value *GuardCheck = TLI.getSSPStackGuardCheck(M)) { +    // The target provides a guard check function to validate the guard value. +    // Generate a call to that function with the content of the guard slot as +    // argument. +    auto *Fn = cast<Function>(GuardCheck); +    FunctionType *FnTy = Fn->getFunctionType(); +    assert(FnTy->getNumParams() == 1 && "Invalid function signature"); + +    TargetLowering::ArgListTy Args; +    TargetLowering::ArgListEntry Entry; +    Entry.Node = StackSlot; +    Entry.Ty = FnTy->getParamType(0); +    if (Fn->hasAttribute(1, Attribute::AttrKind::InReg)) +      Entry.IsInReg = true; +    Args.push_back(Entry); + +    TargetLowering::CallLoweringInfo CLI(DAG); +    CLI.setDebugLoc(getCurSDLoc()) +      .setChain(DAG.getEntryNode()) +      .setCallee(Fn->getCallingConv(), FnTy->getReturnType(), +                 getValue(GuardCheck), std::move(Args)); + +    std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI); +    DAG.setRoot(Result.second); +    return; +  } + +  // If useLoadStackGuardNode returns true, generate LOAD_STACK_GUARD. +  // Otherwise, emit a volatile load to retrieve the stack guard value. +  SDValue Chain = DAG.getEntryNode(); +  if (TLI.useLoadStackGuardNode()) { +    Guard = getLoadStackGuard(DAG, dl, Chain); +  } else { +    const Value *IRGuard = TLI.getSDagStackGuard(M); +    SDValue GuardPtr = getValue(IRGuard); + +    Guard = +        DAG.getLoad(PtrTy, dl, Chain, GuardPtr, MachinePointerInfo(IRGuard, 0), +                    Align, MachineMemOperand::MOVolatile); +  } + +  // Perform the comparison via a subtract/getsetcc. +  EVT VT = Guard.getValueType(); +  SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, Guard, StackSlot); + +  SDValue Cmp = DAG.getSetCC(dl, TLI.getSetCCResultType(DAG.getDataLayout(), +                                                        *DAG.getContext(), +                                                        Sub.getValueType()), +                             Sub, DAG.getConstant(0, dl, VT), ISD::SETNE); + +  // If the sub is not 0, then we know the guard/stackslot do not equal, so +  // branch to failure MBB. +  SDValue BrCond = DAG.getNode(ISD::BRCOND, dl, +                               MVT::Other, StackSlot.getOperand(0), +                               Cmp, DAG.getBasicBlock(SPD.getFailureMBB())); +  // Otherwise branch to success MBB. +  SDValue Br = DAG.getNode(ISD::BR, dl, +                           MVT::Other, BrCond, +                           DAG.getBasicBlock(SPD.getSuccessMBB())); + +  DAG.setRoot(Br); +} + +/// Codegen the failure basic block for a stack protector check. +/// +/// A failure stack protector machine basic block consists simply of a call to +/// __stack_chk_fail(). +/// +/// For a high level explanation of how this fits into the stack protector +/// generation see the comment on the declaration of class +/// StackProtectorDescriptor. +void +SelectionDAGBuilder::visitSPDescriptorFailure(StackProtectorDescriptor &SPD) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue Chain = +      TLI.makeLibCall(DAG, RTLIB::STACKPROTECTOR_CHECK_FAIL, MVT::isVoid, +                      None, false, getCurSDLoc(), false, false).second; +  DAG.setRoot(Chain); +} + +/// visitBitTestHeader - This function emits necessary code to produce value +/// suitable for "bit tests" +void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B, +                                             MachineBasicBlock *SwitchBB) { +  SDLoc dl = getCurSDLoc(); + +  // Subtract the minimum value +  SDValue SwitchOp = getValue(B.SValue); +  EVT VT = SwitchOp.getValueType(); +  SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp, +                            DAG.getConstant(B.First, dl, VT)); + +  // Check range +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue RangeCmp = DAG.getSetCC( +      dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), +                                 Sub.getValueType()), +      Sub, DAG.getConstant(B.Range, dl, VT), ISD::SETUGT); + +  // Determine the type of the test operands. +  bool UsePtrType = false; +  if (!TLI.isTypeLegal(VT)) +    UsePtrType = true; +  else { +    for (unsigned i = 0, e = B.Cases.size(); i != e; ++i) +      if (!isUIntN(VT.getSizeInBits(), B.Cases[i].Mask)) { +        // Switch table case range are encoded into series of masks. +        // Just use pointer type, it's guaranteed to fit. +        UsePtrType = true; +        break; +      } +  } +  if (UsePtrType) { +    VT = TLI.getPointerTy(DAG.getDataLayout()); +    Sub = DAG.getZExtOrTrunc(Sub, dl, VT); +  } + +  B.RegVT = VT.getSimpleVT(); +  B.Reg = FuncInfo.CreateReg(B.RegVT); +  SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl, B.Reg, Sub); + +  MachineBasicBlock* MBB = B.Cases[0].ThisBB; + +  addSuccessorWithProb(SwitchBB, B.Default, B.DefaultProb); +  addSuccessorWithProb(SwitchBB, MBB, B.Prob); +  SwitchBB->normalizeSuccProbs(); + +  SDValue BrRange = DAG.getNode(ISD::BRCOND, dl, +                                MVT::Other, CopyTo, RangeCmp, +                                DAG.getBasicBlock(B.Default)); + +  // Avoid emitting unnecessary branches to the next block. +  if (MBB != NextBlock(SwitchBB)) +    BrRange = DAG.getNode(ISD::BR, dl, MVT::Other, BrRange, +                          DAG.getBasicBlock(MBB)); + +  DAG.setRoot(BrRange); +} + +/// visitBitTestCase - this function produces one "bit test" +void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB, +                                           MachineBasicBlock* NextMBB, +                                           BranchProbability BranchProbToNext, +                                           unsigned Reg, +                                           BitTestCase &B, +                                           MachineBasicBlock *SwitchBB) { +  SDLoc dl = getCurSDLoc(); +  MVT VT = BB.RegVT; +  SDValue ShiftOp = DAG.getCopyFromReg(getControlRoot(), dl, Reg, VT); +  SDValue Cmp; +  unsigned PopCount = countPopulation(B.Mask); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  if (PopCount == 1) { +    // Testing for a single bit; just compare the shift count with what it +    // would need to be to shift a 1 bit in that position. +    Cmp = DAG.getSetCC( +        dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT), +        ShiftOp, DAG.getConstant(countTrailingZeros(B.Mask), dl, VT), +        ISD::SETEQ); +  } else if (PopCount == BB.Range) { +    // There is only one zero bit in the range, test for it directly. +    Cmp = DAG.getSetCC( +        dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT), +        ShiftOp, DAG.getConstant(countTrailingOnes(B.Mask), dl, VT), +        ISD::SETNE); +  } else { +    // Make desired shift +    SDValue SwitchVal = DAG.getNode(ISD::SHL, dl, VT, +                                    DAG.getConstant(1, dl, VT), ShiftOp); + +    // Emit bit tests and jumps +    SDValue AndOp = DAG.getNode(ISD::AND, dl, +                                VT, SwitchVal, DAG.getConstant(B.Mask, dl, VT)); +    Cmp = DAG.getSetCC( +        dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT), +        AndOp, DAG.getConstant(0, dl, VT), ISD::SETNE); +  } + +  // The branch probability from SwitchBB to B.TargetBB is B.ExtraProb. +  addSuccessorWithProb(SwitchBB, B.TargetBB, B.ExtraProb); +  // The branch probability from SwitchBB to NextMBB is BranchProbToNext. +  addSuccessorWithProb(SwitchBB, NextMBB, BranchProbToNext); +  // It is not guaranteed that the sum of B.ExtraProb and BranchProbToNext is +  // one as they are relative probabilities (and thus work more like weights), +  // and hence we need to normalize them to let the sum of them become one. +  SwitchBB->normalizeSuccProbs(); + +  SDValue BrAnd = DAG.getNode(ISD::BRCOND, dl, +                              MVT::Other, getControlRoot(), +                              Cmp, DAG.getBasicBlock(B.TargetBB)); + +  // Avoid emitting unnecessary branches to the next block. +  if (NextMBB != NextBlock(SwitchBB)) +    BrAnd = DAG.getNode(ISD::BR, dl, MVT::Other, BrAnd, +                        DAG.getBasicBlock(NextMBB)); + +  DAG.setRoot(BrAnd); +} + +void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) { +  MachineBasicBlock *InvokeMBB = FuncInfo.MBB; + +  // Retrieve successors. Look through artificial IR level blocks like +  // catchswitch for successors. +  MachineBasicBlock *Return = FuncInfo.MBBMap[I.getSuccessor(0)]; +  const BasicBlock *EHPadBB = I.getSuccessor(1); + +  // Deopt bundles are lowered in LowerCallSiteWithDeoptBundle, and we don't +  // have to do anything here to lower funclet bundles. +  assert(!I.hasOperandBundlesOtherThan( +             {LLVMContext::OB_deopt, LLVMContext::OB_funclet}) && +         "Cannot lower invokes with arbitrary operand bundles yet!"); + +  const Value *Callee(I.getCalledValue()); +  const Function *Fn = dyn_cast<Function>(Callee); +  if (isa<InlineAsm>(Callee)) +    visitInlineAsm(&I); +  else if (Fn && Fn->isIntrinsic()) { +    switch (Fn->getIntrinsicID()) { +    default: +      llvm_unreachable("Cannot invoke this intrinsic"); +    case Intrinsic::donothing: +      // Ignore invokes to @llvm.donothing: jump directly to the next BB. +      break; +    case Intrinsic::experimental_patchpoint_void: +    case Intrinsic::experimental_patchpoint_i64: +      visitPatchpoint(&I, EHPadBB); +      break; +    case Intrinsic::experimental_gc_statepoint: +      LowerStatepoint(ImmutableStatepoint(&I), EHPadBB); +      break; +    } +  } else if (I.countOperandBundlesOfType(LLVMContext::OB_deopt)) { +    // Currently we do not lower any intrinsic calls with deopt operand bundles. +    // Eventually we will support lowering the @llvm.experimental.deoptimize +    // intrinsic, and right now there are no plans to support other intrinsics +    // with deopt state. +    LowerCallSiteWithDeoptBundle(&I, getValue(Callee), EHPadBB); +  } else { +    LowerCallTo(&I, getValue(Callee), false, EHPadBB); +  } + +  // If the value of the invoke is used outside of its defining block, make it +  // available as a virtual register. +  // We already took care of the exported value for the statepoint instruction +  // during call to the LowerStatepoint. +  if (!isStatepoint(I)) { +    CopyToExportRegsIfNeeded(&I); +  } + +  SmallVector<std::pair<MachineBasicBlock *, BranchProbability>, 1> UnwindDests; +  BranchProbabilityInfo *BPI = FuncInfo.BPI; +  BranchProbability EHPadBBProb = +      BPI ? BPI->getEdgeProbability(InvokeMBB->getBasicBlock(), EHPadBB) +          : BranchProbability::getZero(); +  findUnwindDestinations(FuncInfo, EHPadBB, EHPadBBProb, UnwindDests); + +  // Update successor info. +  addSuccessorWithProb(InvokeMBB, Return); +  for (auto &UnwindDest : UnwindDests) { +    UnwindDest.first->setIsEHPad(); +    addSuccessorWithProb(InvokeMBB, UnwindDest.first, UnwindDest.second); +  } +  InvokeMBB->normalizeSuccProbs(); + +  // Drop into normal successor. +  DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), +                          MVT::Other, getControlRoot(), +                          DAG.getBasicBlock(Return))); +} + +void SelectionDAGBuilder::visitResume(const ResumeInst &RI) { +  llvm_unreachable("SelectionDAGBuilder shouldn't visit resume instructions!"); +} + +void SelectionDAGBuilder::visitLandingPad(const LandingPadInst &LP) { +  assert(FuncInfo.MBB->isEHPad() && +         "Call to landingpad not in landing pad!"); + +  MachineBasicBlock *MBB = FuncInfo.MBB; +  addLandingPadInfo(LP, *MBB); + +  // If there aren't registers to copy the values into (e.g., during SjLj +  // exceptions), then don't bother to create these DAG nodes. +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  const Constant *PersonalityFn = FuncInfo.Fn->getPersonalityFn(); +  if (TLI.getExceptionPointerRegister(PersonalityFn) == 0 && +      TLI.getExceptionSelectorRegister(PersonalityFn) == 0) +    return; + +  // If landingpad's return type is token type, we don't create DAG nodes +  // for its exception pointer and selector value. The extraction of exception +  // pointer or selector value from token type landingpads is not currently +  // supported. +  if (LP.getType()->isTokenTy()) +    return; + +  SmallVector<EVT, 2> ValueVTs; +  SDLoc dl = getCurSDLoc(); +  ComputeValueVTs(TLI, DAG.getDataLayout(), LP.getType(), ValueVTs); +  assert(ValueVTs.size() == 2 && "Only two-valued landingpads are supported"); + +  // Get the two live-in registers as SDValues. The physregs have already been +  // copied into virtual registers. +  SDValue Ops[2]; +  if (FuncInfo.ExceptionPointerVirtReg) { +    Ops[0] = DAG.getZExtOrTrunc( +        DAG.getCopyFromReg(DAG.getEntryNode(), dl, +                           FuncInfo.ExceptionPointerVirtReg, +                           TLI.getPointerTy(DAG.getDataLayout())), +        dl, ValueVTs[0]); +  } else { +    Ops[0] = DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout())); +  } +  Ops[1] = DAG.getZExtOrTrunc( +      DAG.getCopyFromReg(DAG.getEntryNode(), dl, +                         FuncInfo.ExceptionSelectorVirtReg, +                         TLI.getPointerTy(DAG.getDataLayout())), +      dl, ValueVTs[1]); + +  // Merge into one. +  SDValue Res = DAG.getNode(ISD::MERGE_VALUES, dl, +                            DAG.getVTList(ValueVTs), Ops); +  setValue(&LP, Res); +} + +void SelectionDAGBuilder::sortAndRangeify(CaseClusterVector &Clusters) { +#ifndef NDEBUG +  for (const CaseCluster &CC : Clusters) +    assert(CC.Low == CC.High && "Input clusters must be single-case"); +#endif + +  std::sort(Clusters.begin(), Clusters.end(), +            [](const CaseCluster &a, const CaseCluster &b) { +    return a.Low->getValue().slt(b.Low->getValue()); +  }); + +  // Merge adjacent clusters with the same destination. +  const unsigned N = Clusters.size(); +  unsigned DstIndex = 0; +  for (unsigned SrcIndex = 0; SrcIndex < N; ++SrcIndex) { +    CaseCluster &CC = Clusters[SrcIndex]; +    const ConstantInt *CaseVal = CC.Low; +    MachineBasicBlock *Succ = CC.MBB; + +    if (DstIndex != 0 && Clusters[DstIndex - 1].MBB == Succ && +        (CaseVal->getValue() - Clusters[DstIndex - 1].High->getValue()) == 1) { +      // If this case has the same successor and is a neighbour, merge it into +      // the previous cluster. +      Clusters[DstIndex - 1].High = CaseVal; +      Clusters[DstIndex - 1].Prob += CC.Prob; +    } else { +      std::memmove(&Clusters[DstIndex++], &Clusters[SrcIndex], +                   sizeof(Clusters[SrcIndex])); +    } +  } +  Clusters.resize(DstIndex); +} + +void SelectionDAGBuilder::UpdateSplitBlock(MachineBasicBlock *First, +                                           MachineBasicBlock *Last) { +  // Update JTCases. +  for (unsigned i = 0, e = JTCases.size(); i != e; ++i) +    if (JTCases[i].first.HeaderBB == First) +      JTCases[i].first.HeaderBB = Last; + +  // Update BitTestCases. +  for (unsigned i = 0, e = BitTestCases.size(); i != e; ++i) +    if (BitTestCases[i].Parent == First) +      BitTestCases[i].Parent = Last; +} + +void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) { +  MachineBasicBlock *IndirectBrMBB = FuncInfo.MBB; + +  // Update machine-CFG edges with unique successors. +  SmallSet<BasicBlock*, 32> Done; +  for (unsigned i = 0, e = I.getNumSuccessors(); i != e; ++i) { +    BasicBlock *BB = I.getSuccessor(i); +    bool Inserted = Done.insert(BB).second; +    if (!Inserted) +        continue; + +    MachineBasicBlock *Succ = FuncInfo.MBBMap[BB]; +    addSuccessorWithProb(IndirectBrMBB, Succ); +  } +  IndirectBrMBB->normalizeSuccProbs(); + +  DAG.setRoot(DAG.getNode(ISD::BRIND, getCurSDLoc(), +                          MVT::Other, getControlRoot(), +                          getValue(I.getAddress()))); +} + +void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) { +  if (DAG.getTarget().Options.TrapUnreachable) +    DAG.setRoot( +        DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot())); +} + +void SelectionDAGBuilder::visitFSub(const User &I) { +  // -0.0 - X --> fneg +  Type *Ty = I.getType(); +  if (isa<Constant>(I.getOperand(0)) && +      I.getOperand(0) == ConstantFP::getZeroValueForNegation(Ty)) { +    SDValue Op2 = getValue(I.getOperand(1)); +    setValue(&I, DAG.getNode(ISD::FNEG, getCurSDLoc(), +                             Op2.getValueType(), Op2)); +    return; +  } + +  visitBinary(I, ISD::FSUB); +} + +/// Checks if the given instruction performs a vector reduction, in which case +/// we have the freedom to alter the elements in the result as long as the +/// reduction of them stays unchanged. +static bool isVectorReductionOp(const User *I) { +  const Instruction *Inst = dyn_cast<Instruction>(I); +  if (!Inst || !Inst->getType()->isVectorTy()) +    return false; + +  auto OpCode = Inst->getOpcode(); +  switch (OpCode) { +  case Instruction::Add: +  case Instruction::Mul: +  case Instruction::And: +  case Instruction::Or: +  case Instruction::Xor: +    break; +  case Instruction::FAdd: +  case Instruction::FMul: +    if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(Inst)) +      if (FPOp->getFastMathFlags().unsafeAlgebra()) +        break; +    LLVM_FALLTHROUGH; +  default: +    return false; +  } + +  unsigned ElemNum = Inst->getType()->getVectorNumElements(); +  unsigned ElemNumToReduce = ElemNum; + +  // Do DFS search on the def-use chain from the given instruction. We only +  // allow four kinds of operations during the search until we reach the +  // instruction that extracts the first element from the vector: +  // +  //   1. The reduction operation of the same opcode as the given instruction. +  // +  //   2. PHI node. +  // +  //   3. ShuffleVector instruction together with a reduction operation that +  //      does a partial reduction. +  // +  //   4. ExtractElement that extracts the first element from the vector, and we +  //      stop searching the def-use chain here. +  // +  // 3 & 4 above perform a reduction on all elements of the vector. We push defs +  // from 1-3 to the stack to continue the DFS. The given instruction is not +  // a reduction operation if we meet any other instructions other than those +  // listed above. + +  SmallVector<const User *, 16> UsersToVisit{Inst}; +  SmallPtrSet<const User *, 16> Visited; +  bool ReduxExtracted = false; + +  while (!UsersToVisit.empty()) { +    auto User = UsersToVisit.back(); +    UsersToVisit.pop_back(); +    if (!Visited.insert(User).second) +      continue; + +    for (const auto &U : User->users()) { +      auto Inst = dyn_cast<Instruction>(U); +      if (!Inst) +        return false; + +      if (Inst->getOpcode() == OpCode || isa<PHINode>(U)) { +        if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(Inst)) +          if (!isa<PHINode>(FPOp) && !FPOp->getFastMathFlags().unsafeAlgebra()) +            return false; +        UsersToVisit.push_back(U); +      } else if (const ShuffleVectorInst *ShufInst = +                     dyn_cast<ShuffleVectorInst>(U)) { +        // Detect the following pattern: A ShuffleVector instruction together +        // with a reduction that do partial reduction on the first and second +        // ElemNumToReduce / 2 elements, and store the result in +        // ElemNumToReduce / 2 elements in another vector. + +        unsigned ResultElements = ShufInst->getType()->getVectorNumElements(); +        if (ResultElements < ElemNum) +          return false; + +        if (ElemNumToReduce == 1) +          return false; +        if (!isa<UndefValue>(U->getOperand(1))) +          return false; +        for (unsigned i = 0; i < ElemNumToReduce / 2; ++i) +          if (ShufInst->getMaskValue(i) != int(i + ElemNumToReduce / 2)) +            return false; +        for (unsigned i = ElemNumToReduce / 2; i < ElemNum; ++i) +          if (ShufInst->getMaskValue(i) != -1) +            return false; + +        // There is only one user of this ShuffleVector instruction, which +        // must be a reduction operation. +        if (!U->hasOneUse()) +          return false; + +        auto U2 = dyn_cast<Instruction>(*U->user_begin()); +        if (!U2 || U2->getOpcode() != OpCode) +          return false; + +        // Check operands of the reduction operation. +        if ((U2->getOperand(0) == U->getOperand(0) && U2->getOperand(1) == U) || +            (U2->getOperand(1) == U->getOperand(0) && U2->getOperand(0) == U)) { +          UsersToVisit.push_back(U2); +          ElemNumToReduce /= 2; +        } else +          return false; +      } else if (isa<ExtractElementInst>(U)) { +        // At this moment we should have reduced all elements in the vector. +        if (ElemNumToReduce != 1) +          return false; + +        const ConstantInt *Val = dyn_cast<ConstantInt>(U->getOperand(1)); +        if (!Val || Val->getZExtValue() != 0) +          return false; + +        ReduxExtracted = true; +      } else +        return false; +    } +  } +  return ReduxExtracted; +} + +void SelectionDAGBuilder::visitBinary(const User &I, unsigned OpCode) { +  SDValue Op1 = getValue(I.getOperand(0)); +  SDValue Op2 = getValue(I.getOperand(1)); + +  bool nuw = false; +  bool nsw = false; +  bool exact = false; +  bool vec_redux = false; +  FastMathFlags FMF; + +  if (const OverflowingBinaryOperator *OFBinOp = +          dyn_cast<const OverflowingBinaryOperator>(&I)) { +    nuw = OFBinOp->hasNoUnsignedWrap(); +    nsw = OFBinOp->hasNoSignedWrap(); +  } +  if (const PossiblyExactOperator *ExactOp = +          dyn_cast<const PossiblyExactOperator>(&I)) +    exact = ExactOp->isExact(); +  if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(&I)) +    FMF = FPOp->getFastMathFlags(); + +  if (isVectorReductionOp(&I)) { +    vec_redux = true; +    DEBUG(dbgs() << "Detected a reduction operation:" << I << "\n"); +  } + +  SDNodeFlags Flags; +  Flags.setExact(exact); +  Flags.setNoSignedWrap(nsw); +  Flags.setNoUnsignedWrap(nuw); +  Flags.setVectorReduction(vec_redux); +  Flags.setAllowReciprocal(FMF.allowReciprocal()); +  Flags.setAllowContract(FMF.allowContract()); +  Flags.setNoInfs(FMF.noInfs()); +  Flags.setNoNaNs(FMF.noNaNs()); +  Flags.setNoSignedZeros(FMF.noSignedZeros()); +  Flags.setUnsafeAlgebra(FMF.unsafeAlgebra()); + +  SDValue BinNodeValue = DAG.getNode(OpCode, getCurSDLoc(), Op1.getValueType(), +                                     Op1, Op2, Flags); +  setValue(&I, BinNodeValue); +} + +void SelectionDAGBuilder::visitShift(const User &I, unsigned Opcode) { +  SDValue Op1 = getValue(I.getOperand(0)); +  SDValue Op2 = getValue(I.getOperand(1)); + +  EVT ShiftTy = DAG.getTargetLoweringInfo().getShiftAmountTy( +      Op2.getValueType(), DAG.getDataLayout()); + +  // Coerce the shift amount to the right type if we can. +  if (!I.getType()->isVectorTy() && Op2.getValueType() != ShiftTy) { +    unsigned ShiftSize = ShiftTy.getSizeInBits(); +    unsigned Op2Size = Op2.getValueSizeInBits(); +    SDLoc DL = getCurSDLoc(); + +    // If the operand is smaller than the shift count type, promote it. +    if (ShiftSize > Op2Size) +      Op2 = DAG.getNode(ISD::ZERO_EXTEND, DL, ShiftTy, Op2); + +    // If the operand is larger than the shift count type but the shift +    // count type has enough bits to represent any shift value, truncate +    // it now. This is a common case and it exposes the truncate to +    // optimization early. +    else if (ShiftSize >= Log2_32_Ceil(Op2.getValueSizeInBits())) +      Op2 = DAG.getNode(ISD::TRUNCATE, DL, ShiftTy, Op2); +    // Otherwise we'll need to temporarily settle for some other convenient +    // type.  Type legalization will make adjustments once the shiftee is split. +    else +      Op2 = DAG.getZExtOrTrunc(Op2, DL, MVT::i32); +  } + +  bool nuw = false; +  bool nsw = false; +  bool exact = false; + +  if (Opcode == ISD::SRL || Opcode == ISD::SRA || Opcode == ISD::SHL) { + +    if (const OverflowingBinaryOperator *OFBinOp = +            dyn_cast<const OverflowingBinaryOperator>(&I)) { +      nuw = OFBinOp->hasNoUnsignedWrap(); +      nsw = OFBinOp->hasNoSignedWrap(); +    } +    if (const PossiblyExactOperator *ExactOp = +            dyn_cast<const PossiblyExactOperator>(&I)) +      exact = ExactOp->isExact(); +  } +  SDNodeFlags Flags; +  Flags.setExact(exact); +  Flags.setNoSignedWrap(nsw); +  Flags.setNoUnsignedWrap(nuw); +  SDValue Res = DAG.getNode(Opcode, getCurSDLoc(), Op1.getValueType(), Op1, Op2, +                            Flags); +  setValue(&I, Res); +} + +void SelectionDAGBuilder::visitSDiv(const User &I) { +  SDValue Op1 = getValue(I.getOperand(0)); +  SDValue Op2 = getValue(I.getOperand(1)); + +  SDNodeFlags Flags; +  Flags.setExact(isa<PossiblyExactOperator>(&I) && +                 cast<PossiblyExactOperator>(&I)->isExact()); +  setValue(&I, DAG.getNode(ISD::SDIV, getCurSDLoc(), Op1.getValueType(), Op1, +                           Op2, Flags)); +} + +void SelectionDAGBuilder::visitICmp(const User &I) { +  ICmpInst::Predicate predicate = ICmpInst::BAD_ICMP_PREDICATE; +  if (const ICmpInst *IC = dyn_cast<ICmpInst>(&I)) +    predicate = IC->getPredicate(); +  else if (const ConstantExpr *IC = dyn_cast<ConstantExpr>(&I)) +    predicate = ICmpInst::Predicate(IC->getPredicate()); +  SDValue Op1 = getValue(I.getOperand(0)); +  SDValue Op2 = getValue(I.getOperand(1)); +  ISD::CondCode Opcode = getICmpCondCode(predicate); + +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Opcode)); +} + +void SelectionDAGBuilder::visitFCmp(const User &I) { +  FCmpInst::Predicate predicate = FCmpInst::BAD_FCMP_PREDICATE; +  if (const FCmpInst *FC = dyn_cast<FCmpInst>(&I)) +    predicate = FC->getPredicate(); +  else if (const ConstantExpr *FC = dyn_cast<ConstantExpr>(&I)) +    predicate = FCmpInst::Predicate(FC->getPredicate()); +  SDValue Op1 = getValue(I.getOperand(0)); +  SDValue Op2 = getValue(I.getOperand(1)); +  ISD::CondCode Condition = getFCmpCondCode(predicate); + +  // FIXME: Fcmp instructions have fast-math-flags in IR, so we should use them. +  // FIXME: We should propagate the fast-math-flags to the DAG node itself for +  // further optimization, but currently FMF is only applicable to binary nodes. +  if (TM.Options.NoNaNsFPMath) +    Condition = getFCmpCodeWithoutNaN(Condition); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Condition)); +} + +// Check if the condition of the select has one use or two users that are both +// selects with the same condition. +static bool hasOnlySelectUsers(const Value *Cond) { +  return all_of(Cond->users(), [](const Value *V) { +    return isa<SelectInst>(V); +  }); +} + +void SelectionDAGBuilder::visitSelect(const User &I) { +  SmallVector<EVT, 4> ValueVTs; +  ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), I.getType(), +                  ValueVTs); +  unsigned NumValues = ValueVTs.size(); +  if (NumValues == 0) return; + +  SmallVector<SDValue, 4> Values(NumValues); +  SDValue Cond     = getValue(I.getOperand(0)); +  SDValue LHSVal   = getValue(I.getOperand(1)); +  SDValue RHSVal   = getValue(I.getOperand(2)); +  auto BaseOps = {Cond}; +  ISD::NodeType OpCode = Cond.getValueType().isVector() ? +    ISD::VSELECT : ISD::SELECT; + +  // Min/max matching is only viable if all output VTs are the same. +  if (std::equal(ValueVTs.begin(), ValueVTs.end(), ValueVTs.begin())) { +    EVT VT = ValueVTs[0]; +    LLVMContext &Ctx = *DAG.getContext(); +    auto &TLI = DAG.getTargetLoweringInfo(); + +    // We care about the legality of the operation after it has been type +    // legalized. +    while (TLI.getTypeAction(Ctx, VT) != TargetLoweringBase::TypeLegal && +           VT != TLI.getTypeToTransformTo(Ctx, VT)) +      VT = TLI.getTypeToTransformTo(Ctx, VT); + +    // If the vselect is legal, assume we want to leave this as a vector setcc + +    // vselect. Otherwise, if this is going to be scalarized, we want to see if +    // min/max is legal on the scalar type. +    bool UseScalarMinMax = VT.isVector() && +      !TLI.isOperationLegalOrCustom(ISD::VSELECT, VT); + +    Value *LHS, *RHS; +    auto SPR = matchSelectPattern(const_cast<User*>(&I), LHS, RHS); +    ISD::NodeType Opc = ISD::DELETED_NODE; +    switch (SPR.Flavor) { +    case SPF_UMAX:    Opc = ISD::UMAX; break; +    case SPF_UMIN:    Opc = ISD::UMIN; break; +    case SPF_SMAX:    Opc = ISD::SMAX; break; +    case SPF_SMIN:    Opc = ISD::SMIN; break; +    case SPF_FMINNUM: +      switch (SPR.NaNBehavior) { +      case SPNB_NA: llvm_unreachable("No NaN behavior for FP op?"); +      case SPNB_RETURNS_NAN:   Opc = ISD::FMINNAN; break; +      case SPNB_RETURNS_OTHER: Opc = ISD::FMINNUM; break; +      case SPNB_RETURNS_ANY: { +        if (TLI.isOperationLegalOrCustom(ISD::FMINNUM, VT)) +          Opc = ISD::FMINNUM; +        else if (TLI.isOperationLegalOrCustom(ISD::FMINNAN, VT)) +          Opc = ISD::FMINNAN; +        else if (UseScalarMinMax) +          Opc = TLI.isOperationLegalOrCustom(ISD::FMINNUM, VT.getScalarType()) ? +            ISD::FMINNUM : ISD::FMINNAN; +        break; +      } +      } +      break; +    case SPF_FMAXNUM: +      switch (SPR.NaNBehavior) { +      case SPNB_NA: llvm_unreachable("No NaN behavior for FP op?"); +      case SPNB_RETURNS_NAN:   Opc = ISD::FMAXNAN; break; +      case SPNB_RETURNS_OTHER: Opc = ISD::FMAXNUM; break; +      case SPNB_RETURNS_ANY: + +        if (TLI.isOperationLegalOrCustom(ISD::FMAXNUM, VT)) +          Opc = ISD::FMAXNUM; +        else if (TLI.isOperationLegalOrCustom(ISD::FMAXNAN, VT)) +          Opc = ISD::FMAXNAN; +        else if (UseScalarMinMax) +          Opc = TLI.isOperationLegalOrCustom(ISD::FMAXNUM, VT.getScalarType()) ? +            ISD::FMAXNUM : ISD::FMAXNAN; +        break; +      } +      break; +    default: break; +    } + +    if (Opc != ISD::DELETED_NODE && +        (TLI.isOperationLegalOrCustom(Opc, VT) || +         (UseScalarMinMax && +          TLI.isOperationLegalOrCustom(Opc, VT.getScalarType()))) && +        // If the underlying comparison instruction is used by any other +        // instruction, the consumed instructions won't be destroyed, so it is +        // not profitable to convert to a min/max. +        hasOnlySelectUsers(cast<SelectInst>(I).getCondition())) { +      OpCode = Opc; +      LHSVal = getValue(LHS); +      RHSVal = getValue(RHS); +      BaseOps = {}; +    } +  } + +  for (unsigned i = 0; i != NumValues; ++i) { +    SmallVector<SDValue, 3> Ops(BaseOps.begin(), BaseOps.end()); +    Ops.push_back(SDValue(LHSVal.getNode(), LHSVal.getResNo() + i)); +    Ops.push_back(SDValue(RHSVal.getNode(), RHSVal.getResNo() + i)); +    Values[i] = DAG.getNode(OpCode, getCurSDLoc(), +                            LHSVal.getNode()->getValueType(LHSVal.getResNo()+i), +                            Ops); +  } + +  setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(), +                           DAG.getVTList(ValueVTs), Values)); +} + +void SelectionDAGBuilder::visitTrunc(const User &I) { +  // TruncInst cannot be a no-op cast because sizeof(src) > sizeof(dest). +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitZExt(const User &I) { +  // ZExt cannot be a no-op cast because sizeof(src) < sizeof(dest). +  // ZExt also can't be a cast to bool for same reason. So, nothing much to do +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::ZERO_EXTEND, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitSExt(const User &I) { +  // SExt cannot be a no-op cast because sizeof(src) < sizeof(dest). +  // SExt also can't be a cast to bool for same reason. So, nothing much to do +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::SIGN_EXTEND, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitFPTrunc(const User &I) { +  // FPTrunc is never a no-op cast, no need to check +  SDValue N = getValue(I.getOperand(0)); +  SDLoc dl = getCurSDLoc(); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType()); +  setValue(&I, DAG.getNode(ISD::FP_ROUND, dl, DestVT, N, +                           DAG.getTargetConstant( +                               0, dl, TLI.getPointerTy(DAG.getDataLayout())))); +} + +void SelectionDAGBuilder::visitFPExt(const User &I) { +  // FPExt is never a no-op cast, no need to check +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::FP_EXTEND, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitFPToUI(const User &I) { +  // FPToUI is never a no-op cast, no need to check +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::FP_TO_UINT, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitFPToSI(const User &I) { +  // FPToSI is never a no-op cast, no need to check +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::FP_TO_SINT, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitUIToFP(const User &I) { +  // UIToFP is never a no-op cast, no need to check +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::UINT_TO_FP, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitSIToFP(const User &I) { +  // SIToFP is never a no-op cast, no need to check +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getNode(ISD::SINT_TO_FP, getCurSDLoc(), DestVT, N)); +} + +void SelectionDAGBuilder::visitPtrToInt(const User &I) { +  // What to do depends on the size of the integer and the size of the pointer. +  // We can either truncate, zero extend, or no-op, accordingly. +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT)); +} + +void SelectionDAGBuilder::visitIntToPtr(const User &I) { +  // What to do depends on the size of the integer and the size of the pointer. +  // We can either truncate, zero extend, or no-op, accordingly. +  SDValue N = getValue(I.getOperand(0)); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); +  setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT)); +} + +void SelectionDAGBuilder::visitBitCast(const User &I) { +  SDValue N = getValue(I.getOperand(0)); +  SDLoc dl = getCurSDLoc(); +  EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                        I.getType()); + +  // BitCast assures us that source and destination are the same size so this is +  // either a BITCAST or a no-op. +  if (DestVT != N.getValueType()) +    setValue(&I, DAG.getNode(ISD::BITCAST, dl, +                             DestVT, N)); // convert types. +  // Check if the original LLVM IR Operand was a ConstantInt, because getValue() +  // might fold any kind of constant expression to an integer constant and that +  // is not what we are looking for. Only recognize a bitcast of a genuine +  // constant integer as an opaque constant. +  else if(ConstantInt *C = dyn_cast<ConstantInt>(I.getOperand(0))) +    setValue(&I, DAG.getConstant(C->getValue(), dl, DestVT, /*isTarget=*/false, +                                 /*isOpaque*/true)); +  else +    setValue(&I, N);            // noop cast. +} + +void SelectionDAGBuilder::visitAddrSpaceCast(const User &I) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  const Value *SV = I.getOperand(0); +  SDValue N = getValue(SV); +  EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType()); + +  unsigned SrcAS = SV->getType()->getPointerAddressSpace(); +  unsigned DestAS = I.getType()->getPointerAddressSpace(); + +  if (!TLI.isNoopAddrSpaceCast(SrcAS, DestAS)) +    N = DAG.getAddrSpaceCast(getCurSDLoc(), DestVT, N, SrcAS, DestAS); + +  setValue(&I, N); +} + +void SelectionDAGBuilder::visitInsertElement(const User &I) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue InVec = getValue(I.getOperand(0)); +  SDValue InVal = getValue(I.getOperand(1)); +  SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(2)), getCurSDLoc(), +                                     TLI.getVectorIdxTy(DAG.getDataLayout())); +  setValue(&I, DAG.getNode(ISD::INSERT_VECTOR_ELT, getCurSDLoc(), +                           TLI.getValueType(DAG.getDataLayout(), I.getType()), +                           InVec, InVal, InIdx)); +} + +void SelectionDAGBuilder::visitExtractElement(const User &I) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue InVec = getValue(I.getOperand(0)); +  SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(1)), getCurSDLoc(), +                                     TLI.getVectorIdxTy(DAG.getDataLayout())); +  setValue(&I, DAG.getNode(ISD::EXTRACT_VECTOR_ELT, getCurSDLoc(), +                           TLI.getValueType(DAG.getDataLayout(), I.getType()), +                           InVec, InIdx)); +} + +void SelectionDAGBuilder::visitShuffleVector(const User &I) { +  SDValue Src1 = getValue(I.getOperand(0)); +  SDValue Src2 = getValue(I.getOperand(1)); +  SDLoc DL = getCurSDLoc(); + +  SmallVector<int, 8> Mask; +  ShuffleVectorInst::getShuffleMask(cast<Constant>(I.getOperand(2)), Mask); +  unsigned MaskNumElts = Mask.size(); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); +  EVT SrcVT = Src1.getValueType(); +  unsigned SrcNumElts = SrcVT.getVectorNumElements(); + +  if (SrcNumElts == MaskNumElts) { +    setValue(&I, DAG.getVectorShuffle(VT, DL, Src1, Src2, Mask)); +    return; +  } + +  // Normalize the shuffle vector since mask and vector length don't match. +  if (SrcNumElts < MaskNumElts) { +    // Mask is longer than the source vectors. We can use concatenate vector to +    // make the mask and vectors lengths match. + +    if (MaskNumElts % SrcNumElts == 0) { +      // Mask length is a multiple of the source vector length. +      // Check if the shuffle is some kind of concatenation of the input +      // vectors. +      unsigned NumConcat = MaskNumElts / SrcNumElts; +      bool IsConcat = true; +      SmallVector<int, 8> ConcatSrcs(NumConcat, -1); +      for (unsigned i = 0; i != MaskNumElts; ++i) { +        int Idx = Mask[i]; +        if (Idx < 0) +          continue; +        // Ensure the indices in each SrcVT sized piece are sequential and that +        // the same source is used for the whole piece. +        if ((Idx % SrcNumElts != (i % SrcNumElts)) || +            (ConcatSrcs[i / SrcNumElts] >= 0 && +             ConcatSrcs[i / SrcNumElts] != (int)(Idx / SrcNumElts))) { +          IsConcat = false; +          break; +        } +        // Remember which source this index came from. +        ConcatSrcs[i / SrcNumElts] = Idx / SrcNumElts; +      } + +      // The shuffle is concatenating multiple vectors together. Just emit +      // a CONCAT_VECTORS operation. +      if (IsConcat) { +        SmallVector<SDValue, 8> ConcatOps; +        for (auto Src : ConcatSrcs) { +          if (Src < 0) +            ConcatOps.push_back(DAG.getUNDEF(SrcVT)); +          else if (Src == 0) +            ConcatOps.push_back(Src1); +          else +            ConcatOps.push_back(Src2); +        } +        setValue(&I, DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, ConcatOps)); +        return; +      } +    } + +    unsigned PaddedMaskNumElts = alignTo(MaskNumElts, SrcNumElts); +    unsigned NumConcat = PaddedMaskNumElts / SrcNumElts; +    EVT PaddedVT = EVT::getVectorVT(*DAG.getContext(), VT.getScalarType(), +                                    PaddedMaskNumElts); + +    // Pad both vectors with undefs to make them the same length as the mask. +    SDValue UndefVal = DAG.getUNDEF(SrcVT); + +    SmallVector<SDValue, 8> MOps1(NumConcat, UndefVal); +    SmallVector<SDValue, 8> MOps2(NumConcat, UndefVal); +    MOps1[0] = Src1; +    MOps2[0] = Src2; + +    Src1 = Src1.isUndef() +               ? DAG.getUNDEF(PaddedVT) +               : DAG.getNode(ISD::CONCAT_VECTORS, DL, PaddedVT, MOps1); +    Src2 = Src2.isUndef() +               ? DAG.getUNDEF(PaddedVT) +               : DAG.getNode(ISD::CONCAT_VECTORS, DL, PaddedVT, MOps2); + +    // Readjust mask for new input vector length. +    SmallVector<int, 8> MappedOps(PaddedMaskNumElts, -1); +    for (unsigned i = 0; i != MaskNumElts; ++i) { +      int Idx = Mask[i]; +      if (Idx >= (int)SrcNumElts) +        Idx -= SrcNumElts - PaddedMaskNumElts; +      MappedOps[i] = Idx; +    } + +    SDValue Result = DAG.getVectorShuffle(PaddedVT, DL, Src1, Src2, MappedOps); + +    // If the concatenated vector was padded, extract a subvector with the +    // correct number of elements. +    if (MaskNumElts != PaddedMaskNumElts) +      Result = DAG.getNode( +          ISD::EXTRACT_SUBVECTOR, DL, VT, Result, +          DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))); + +    setValue(&I, Result); +    return; +  } + +  if (SrcNumElts > MaskNumElts) { +    // Analyze the access pattern of the vector to see if we can extract +    // two subvectors and do the shuffle. +    int StartIdx[2] = { -1, -1 };  // StartIdx to extract from +    bool CanExtract = true; +    for (int Idx : Mask) { +      unsigned Input = 0; +      if (Idx < 0) +        continue; + +      if (Idx >= (int)SrcNumElts) { +        Input = 1; +        Idx -= SrcNumElts; +      } + +      // If all the indices come from the same MaskNumElts sized portion of +      // the sources we can use extract. Also make sure the extract wouldn't +      // extract past the end of the source. +      int NewStartIdx = alignDown(Idx, MaskNumElts); +      if (NewStartIdx + MaskNumElts > SrcNumElts || +          (StartIdx[Input] >= 0 && StartIdx[Input] != NewStartIdx)) +        CanExtract = false; +      // Make sure we always update StartIdx as we use it to track if all +      // elements are undef. +      StartIdx[Input] = NewStartIdx; +    } + +    if (StartIdx[0] < 0 && StartIdx[1] < 0) { +      setValue(&I, DAG.getUNDEF(VT)); // Vectors are not used. +      return; +    } +    if (CanExtract) { +      // Extract appropriate subvector and generate a vector shuffle +      for (unsigned Input = 0; Input < 2; ++Input) { +        SDValue &Src = Input == 0 ? Src1 : Src2; +        if (StartIdx[Input] < 0) +          Src = DAG.getUNDEF(VT); +        else { +          Src = DAG.getNode( +              ISD::EXTRACT_SUBVECTOR, DL, VT, Src, +              DAG.getConstant(StartIdx[Input], DL, +                              TLI.getVectorIdxTy(DAG.getDataLayout()))); +        } +      } + +      // Calculate new mask. +      SmallVector<int, 8> MappedOps(Mask.begin(), Mask.end()); +      for (int &Idx : MappedOps) { +        if (Idx >= (int)SrcNumElts) +          Idx -= SrcNumElts + StartIdx[1] - MaskNumElts; +        else if (Idx >= 0) +          Idx -= StartIdx[0]; +      } + +      setValue(&I, DAG.getVectorShuffle(VT, DL, Src1, Src2, MappedOps)); +      return; +    } +  } + +  // We can't use either concat vectors or extract subvectors so fall back to +  // replacing the shuffle with extract and build vector. +  // to insert and build vector. +  EVT EltVT = VT.getVectorElementType(); +  EVT IdxVT = TLI.getVectorIdxTy(DAG.getDataLayout()); +  SmallVector<SDValue,8> Ops; +  for (int Idx : Mask) { +    SDValue Res; + +    if (Idx < 0) { +      Res = DAG.getUNDEF(EltVT); +    } else { +      SDValue &Src = Idx < (int)SrcNumElts ? Src1 : Src2; +      if (Idx >= (int)SrcNumElts) Idx -= SrcNumElts; + +      Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, +                        EltVT, Src, DAG.getConstant(Idx, DL, IdxVT)); +    } + +    Ops.push_back(Res); +  } + +  setValue(&I, DAG.getBuildVector(VT, DL, Ops)); +} + +void SelectionDAGBuilder::visitInsertValue(const InsertValueInst &I) { +  const Value *Op0 = I.getOperand(0); +  const Value *Op1 = I.getOperand(1); +  Type *AggTy = I.getType(); +  Type *ValTy = Op1->getType(); +  bool IntoUndef = isa<UndefValue>(Op0); +  bool FromUndef = isa<UndefValue>(Op1); + +  unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices()); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SmallVector<EVT, 4> AggValueVTs; +  ComputeValueVTs(TLI, DAG.getDataLayout(), AggTy, AggValueVTs); +  SmallVector<EVT, 4> ValValueVTs; +  ComputeValueVTs(TLI, DAG.getDataLayout(), ValTy, ValValueVTs); + +  unsigned NumAggValues = AggValueVTs.size(); +  unsigned NumValValues = ValValueVTs.size(); +  SmallVector<SDValue, 4> Values(NumAggValues); + +  // Ignore an insertvalue that produces an empty object +  if (!NumAggValues) { +    setValue(&I, DAG.getUNDEF(MVT(MVT::Other))); +    return; +  } + +  SDValue Agg = getValue(Op0); +  unsigned i = 0; +  // Copy the beginning value(s) from the original aggregate. +  for (; i != LinearIndex; ++i) +    Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) : +                SDValue(Agg.getNode(), Agg.getResNo() + i); +  // Copy values from the inserted value(s). +  if (NumValValues) { +    SDValue Val = getValue(Op1); +    for (; i != LinearIndex + NumValValues; ++i) +      Values[i] = FromUndef ? DAG.getUNDEF(AggValueVTs[i]) : +                  SDValue(Val.getNode(), Val.getResNo() + i - LinearIndex); +  } +  // Copy remaining value(s) from the original aggregate. +  for (; i != NumAggValues; ++i) +    Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) : +                SDValue(Agg.getNode(), Agg.getResNo() + i); + +  setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(), +                           DAG.getVTList(AggValueVTs), Values)); +} + +void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) { +  const Value *Op0 = I.getOperand(0); +  Type *AggTy = Op0->getType(); +  Type *ValTy = I.getType(); +  bool OutOfUndef = isa<UndefValue>(Op0); + +  unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices()); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SmallVector<EVT, 4> ValValueVTs; +  ComputeValueVTs(TLI, DAG.getDataLayout(), ValTy, ValValueVTs); + +  unsigned NumValValues = ValValueVTs.size(); + +  // Ignore a extractvalue that produces an empty object +  if (!NumValValues) { +    setValue(&I, DAG.getUNDEF(MVT(MVT::Other))); +    return; +  } + +  SmallVector<SDValue, 4> Values(NumValValues); + +  SDValue Agg = getValue(Op0); +  // Copy out the selected value(s). +  for (unsigned i = LinearIndex; i != LinearIndex + NumValValues; ++i) +    Values[i - LinearIndex] = +      OutOfUndef ? +        DAG.getUNDEF(Agg.getNode()->getValueType(Agg.getResNo() + i)) : +        SDValue(Agg.getNode(), Agg.getResNo() + i); + +  setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(), +                           DAG.getVTList(ValValueVTs), Values)); +} + +void SelectionDAGBuilder::visitGetElementPtr(const User &I) { +  Value *Op0 = I.getOperand(0); +  // Note that the pointer operand may be a vector of pointers. Take the scalar +  // element which holds a pointer. +  unsigned AS = Op0->getType()->getScalarType()->getPointerAddressSpace(); +  SDValue N = getValue(Op0); +  SDLoc dl = getCurSDLoc(); + +  // Normalize Vector GEP - all scalar operands should be converted to the +  // splat vector. +  unsigned VectorWidth = I.getType()->isVectorTy() ? +    cast<VectorType>(I.getType())->getVectorNumElements() : 0; + +  if (VectorWidth && !N.getValueType().isVector()) { +    LLVMContext &Context = *DAG.getContext(); +    EVT VT = EVT::getVectorVT(Context, N.getValueType(), VectorWidth); +    N = DAG.getSplatBuildVector(VT, dl, N); +  } + +  for (gep_type_iterator GTI = gep_type_begin(&I), E = gep_type_end(&I); +       GTI != E; ++GTI) { +    const Value *Idx = GTI.getOperand(); +    if (StructType *StTy = GTI.getStructTypeOrNull()) { +      unsigned Field = cast<Constant>(Idx)->getUniqueInteger().getZExtValue(); +      if (Field) { +        // N = N + Offset +        uint64_t Offset = DL->getStructLayout(StTy)->getElementOffset(Field); + +        // In an inbounds GEP with an offset that is nonnegative even when +        // interpreted as signed, assume there is no unsigned overflow. +        SDNodeFlags Flags; +        if (int64_t(Offset) >= 0 && cast<GEPOperator>(I).isInBounds()) +          Flags.setNoUnsignedWrap(true); + +        N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N, +                        DAG.getConstant(Offset, dl, N.getValueType()), Flags); +      } +    } else { +      MVT PtrTy = +          DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout(), AS); +      unsigned PtrSize = PtrTy.getSizeInBits(); +      APInt ElementSize(PtrSize, DL->getTypeAllocSize(GTI.getIndexedType())); + +      // If this is a scalar constant or a splat vector of constants, +      // handle it quickly. +      const auto *CI = dyn_cast<ConstantInt>(Idx); +      if (!CI && isa<ConstantDataVector>(Idx) && +          cast<ConstantDataVector>(Idx)->getSplatValue()) +        CI = cast<ConstantInt>(cast<ConstantDataVector>(Idx)->getSplatValue()); + +      if (CI) { +        if (CI->isZero()) +          continue; +        APInt Offs = ElementSize * CI->getValue().sextOrTrunc(PtrSize); +        LLVMContext &Context = *DAG.getContext(); +        SDValue OffsVal = VectorWidth ? +          DAG.getConstant(Offs, dl, EVT::getVectorVT(Context, PtrTy, VectorWidth)) : +          DAG.getConstant(Offs, dl, PtrTy); + +        // In an inbouds GEP with an offset that is nonnegative even when +        // interpreted as signed, assume there is no unsigned overflow. +        SDNodeFlags Flags; +        if (Offs.isNonNegative() && cast<GEPOperator>(I).isInBounds()) +          Flags.setNoUnsignedWrap(true); + +        N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N, OffsVal, Flags); +        continue; +      } + +      // N = N + Idx * ElementSize; +      SDValue IdxN = getValue(Idx); + +      if (!IdxN.getValueType().isVector() && VectorWidth) { +        MVT VT = MVT::getVectorVT(IdxN.getValueType().getSimpleVT(), VectorWidth); +        IdxN = DAG.getSplatBuildVector(VT, dl, IdxN); +      } + +      // If the index is smaller or larger than intptr_t, truncate or extend +      // it. +      IdxN = DAG.getSExtOrTrunc(IdxN, dl, N.getValueType()); + +      // If this is a multiply by a power of two, turn it into a shl +      // immediately.  This is a very common case. +      if (ElementSize != 1) { +        if (ElementSize.isPowerOf2()) { +          unsigned Amt = ElementSize.logBase2(); +          IdxN = DAG.getNode(ISD::SHL, dl, +                             N.getValueType(), IdxN, +                             DAG.getConstant(Amt, dl, IdxN.getValueType())); +        } else { +          SDValue Scale = DAG.getConstant(ElementSize, dl, IdxN.getValueType()); +          IdxN = DAG.getNode(ISD::MUL, dl, +                             N.getValueType(), IdxN, Scale); +        } +      } + +      N = DAG.getNode(ISD::ADD, dl, +                      N.getValueType(), N, IdxN); +    } +  } + +  setValue(&I, N); +} + +void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) { +  // If this is a fixed sized alloca in the entry block of the function, +  // allocate it statically on the stack. +  if (FuncInfo.StaticAllocaMap.count(&I)) +    return;   // getValue will auto-populate this. + +  SDLoc dl = getCurSDLoc(); +  Type *Ty = I.getAllocatedType(); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  auto &DL = DAG.getDataLayout(); +  uint64_t TySize = DL.getTypeAllocSize(Ty); +  unsigned Align = +      std::max((unsigned)DL.getPrefTypeAlignment(Ty), I.getAlignment()); + +  SDValue AllocSize = getValue(I.getArraySize()); + +  EVT IntPtr = TLI.getPointerTy(DAG.getDataLayout()); +  if (AllocSize.getValueType() != IntPtr) +    AllocSize = DAG.getZExtOrTrunc(AllocSize, dl, IntPtr); + +  AllocSize = DAG.getNode(ISD::MUL, dl, IntPtr, +                          AllocSize, +                          DAG.getConstant(TySize, dl, IntPtr)); + +  // Handle alignment.  If the requested alignment is less than or equal to +  // the stack alignment, ignore it.  If the size is greater than or equal to +  // the stack alignment, we note this in the DYNAMIC_STACKALLOC node. +  unsigned StackAlign = +      DAG.getSubtarget().getFrameLowering()->getStackAlignment(); +  if (Align <= StackAlign) +    Align = 0; + +  // Round the size of the allocation up to the stack alignment size +  // by add SA-1 to the size. This doesn't overflow because we're computing +  // an address inside an alloca. +  SDNodeFlags Flags; +  Flags.setNoUnsignedWrap(true); +  AllocSize = DAG.getNode(ISD::ADD, dl, +                          AllocSize.getValueType(), AllocSize, +                          DAG.getIntPtrConstant(StackAlign - 1, dl), Flags); + +  // Mask out the low bits for alignment purposes. +  AllocSize = DAG.getNode(ISD::AND, dl, +                          AllocSize.getValueType(), AllocSize, +                          DAG.getIntPtrConstant(~(uint64_t)(StackAlign - 1), +                                                dl)); + +  SDValue Ops[] = { getRoot(), AllocSize, DAG.getIntPtrConstant(Align, dl) }; +  SDVTList VTs = DAG.getVTList(AllocSize.getValueType(), MVT::Other); +  SDValue DSA = DAG.getNode(ISD::DYNAMIC_STACKALLOC, dl, VTs, Ops); +  setValue(&I, DSA); +  DAG.setRoot(DSA.getValue(1)); + +  assert(FuncInfo.MF->getFrameInfo().hasVarSizedObjects()); +} + +void SelectionDAGBuilder::visitLoad(const LoadInst &I) { +  if (I.isAtomic()) +    return visitAtomicLoad(I); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  const Value *SV = I.getOperand(0); +  if (TLI.supportSwiftError()) { +    // Swifterror values can come from either a function parameter with +    // swifterror attribute or an alloca with swifterror attribute. +    if (const Argument *Arg = dyn_cast<Argument>(SV)) { +      if (Arg->hasSwiftErrorAttr()) +        return visitLoadFromSwiftError(I); +    } + +    if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(SV)) { +      if (Alloca->isSwiftError()) +        return visitLoadFromSwiftError(I); +    } +  } + +  SDValue Ptr = getValue(SV); + +  Type *Ty = I.getType(); + +  bool isVolatile = I.isVolatile(); +  bool isNonTemporal = I.getMetadata(LLVMContext::MD_nontemporal) != nullptr; +  bool isInvariant = I.getMetadata(LLVMContext::MD_invariant_load) != nullptr; +  bool isDereferenceable = isDereferenceablePointer(SV, DAG.getDataLayout()); +  unsigned Alignment = I.getAlignment(); + +  AAMDNodes AAInfo; +  I.getAAMetadata(AAInfo); +  const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range); + +  SmallVector<EVT, 4> ValueVTs; +  SmallVector<uint64_t, 4> Offsets; +  ComputeValueVTs(TLI, DAG.getDataLayout(), Ty, ValueVTs, &Offsets); +  unsigned NumValues = ValueVTs.size(); +  if (NumValues == 0) +    return; + +  SDValue Root; +  bool ConstantMemory = false; +  if (isVolatile || NumValues > MaxParallelChains) +    // Serialize volatile loads with other side effects. +    Root = getRoot(); +  else if (AA && AA->pointsToConstantMemory(MemoryLocation( +               SV, DAG.getDataLayout().getTypeStoreSize(Ty), AAInfo))) { +    // Do not serialize (non-volatile) loads of constant memory with anything. +    Root = DAG.getEntryNode(); +    ConstantMemory = true; +  } else { +    // Do not serialize non-volatile loads against each other. +    Root = DAG.getRoot(); +  } + +  SDLoc dl = getCurSDLoc(); + +  if (isVolatile) +    Root = TLI.prepareVolatileOrAtomicLoad(Root, dl, DAG); + +  // An aggregate load cannot wrap around the address space, so offsets to its +  // parts don't wrap either. +  SDNodeFlags Flags; +  Flags.setNoUnsignedWrap(true); + +  SmallVector<SDValue, 4> Values(NumValues); +  SmallVector<SDValue, 4> Chains(std::min(MaxParallelChains, NumValues)); +  EVT PtrVT = Ptr.getValueType(); +  unsigned ChainI = 0; +  for (unsigned i = 0; i != NumValues; ++i, ++ChainI) { +    // Serializing loads here may result in excessive register pressure, and +    // TokenFactor places arbitrary choke points on the scheduler. SD scheduling +    // could recover a bit by hoisting nodes upward in the chain by recognizing +    // they are side-effect free or do not alias. The optimizer should really +    // avoid this case by converting large object/array copies to llvm.memcpy +    // (MaxParallelChains should always remain as failsafe). +    if (ChainI == MaxParallelChains) { +      assert(PendingLoads.empty() && "PendingLoads must be serialized first"); +      SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, +                                  makeArrayRef(Chains.data(), ChainI)); +      Root = Chain; +      ChainI = 0; +    } +    SDValue A = DAG.getNode(ISD::ADD, dl, +                            PtrVT, Ptr, +                            DAG.getConstant(Offsets[i], dl, PtrVT), +                            Flags); +    auto MMOFlags = MachineMemOperand::MONone; +    if (isVolatile) +      MMOFlags |= MachineMemOperand::MOVolatile; +    if (isNonTemporal) +      MMOFlags |= MachineMemOperand::MONonTemporal; +    if (isInvariant) +      MMOFlags |= MachineMemOperand::MOInvariant; +    if (isDereferenceable) +      MMOFlags |= MachineMemOperand::MODereferenceable; + +    SDValue L = DAG.getLoad(ValueVTs[i], dl, Root, A, +                            MachinePointerInfo(SV, Offsets[i]), Alignment, +                            MMOFlags, AAInfo, Ranges); + +    Values[i] = L; +    Chains[ChainI] = L.getValue(1); +  } + +  if (!ConstantMemory) { +    SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, +                                makeArrayRef(Chains.data(), ChainI)); +    if (isVolatile) +      DAG.setRoot(Chain); +    else +      PendingLoads.push_back(Chain); +  } + +  setValue(&I, DAG.getNode(ISD::MERGE_VALUES, dl, +                           DAG.getVTList(ValueVTs), Values)); +} + +void SelectionDAGBuilder::visitStoreToSwiftError(const StoreInst &I) { +  assert(DAG.getTargetLoweringInfo().supportSwiftError() && +         "call visitStoreToSwiftError when backend supports swifterror"); + +  SmallVector<EVT, 4> ValueVTs; +  SmallVector<uint64_t, 4> Offsets; +  const Value *SrcV = I.getOperand(0); +  ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), +                  SrcV->getType(), ValueVTs, &Offsets); +  assert(ValueVTs.size() == 1 && Offsets[0] == 0 && +         "expect a single EVT for swifterror"); + +  SDValue Src = getValue(SrcV); +  // Create a virtual register, then update the virtual register. +  unsigned VReg; bool CreatedVReg; +  std::tie(VReg, CreatedVReg) = FuncInfo.getOrCreateSwiftErrorVRegDefAt(&I); +  // Chain, DL, Reg, N or Chain, DL, Reg, N, Glue +  // Chain can be getRoot or getControlRoot. +  SDValue CopyNode = DAG.getCopyToReg(getRoot(), getCurSDLoc(), VReg, +                                      SDValue(Src.getNode(), Src.getResNo())); +  DAG.setRoot(CopyNode); +  if (CreatedVReg) +    FuncInfo.setCurrentSwiftErrorVReg(FuncInfo.MBB, I.getOperand(1), VReg); +} + +void SelectionDAGBuilder::visitLoadFromSwiftError(const LoadInst &I) { +  assert(DAG.getTargetLoweringInfo().supportSwiftError() && +         "call visitLoadFromSwiftError when backend supports swifterror"); + +  assert(!I.isVolatile() && +         I.getMetadata(LLVMContext::MD_nontemporal) == nullptr && +         I.getMetadata(LLVMContext::MD_invariant_load) == nullptr && +         "Support volatile, non temporal, invariant for load_from_swift_error"); + +  const Value *SV = I.getOperand(0); +  Type *Ty = I.getType(); +  AAMDNodes AAInfo; +  I.getAAMetadata(AAInfo); +  assert((!AA || !AA->pointsToConstantMemory(MemoryLocation( +             SV, DAG.getDataLayout().getTypeStoreSize(Ty), AAInfo))) && +         "load_from_swift_error should not be constant memory"); + +  SmallVector<EVT, 4> ValueVTs; +  SmallVector<uint64_t, 4> Offsets; +  ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), Ty, +                  ValueVTs, &Offsets); +  assert(ValueVTs.size() == 1 && Offsets[0] == 0 && +         "expect a single EVT for swifterror"); + +  // Chain, DL, Reg, VT, Glue or Chain, DL, Reg, VT +  SDValue L = DAG.getCopyFromReg( +      getRoot(), getCurSDLoc(), +      FuncInfo.getOrCreateSwiftErrorVRegUseAt(&I, FuncInfo.MBB, SV).first, +      ValueVTs[0]); + +  setValue(&I, L); +} + +void SelectionDAGBuilder::visitStore(const StoreInst &I) { +  if (I.isAtomic()) +    return visitAtomicStore(I); + +  const Value *SrcV = I.getOperand(0); +  const Value *PtrV = I.getOperand(1); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  if (TLI.supportSwiftError()) { +    // Swifterror values can come from either a function parameter with +    // swifterror attribute or an alloca with swifterror attribute. +    if (const Argument *Arg = dyn_cast<Argument>(PtrV)) { +      if (Arg->hasSwiftErrorAttr()) +        return visitStoreToSwiftError(I); +    } + +    if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(PtrV)) { +      if (Alloca->isSwiftError()) +        return visitStoreToSwiftError(I); +    } +  } + +  SmallVector<EVT, 4> ValueVTs; +  SmallVector<uint64_t, 4> Offsets; +  ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), +                  SrcV->getType(), ValueVTs, &Offsets); +  unsigned NumValues = ValueVTs.size(); +  if (NumValues == 0) +    return; + +  // Get the lowered operands. Note that we do this after +  // checking if NumResults is zero, because with zero results +  // the operands won't have values in the map. +  SDValue Src = getValue(SrcV); +  SDValue Ptr = getValue(PtrV); + +  SDValue Root = getRoot(); +  SmallVector<SDValue, 4> Chains(std::min(MaxParallelChains, NumValues)); +  SDLoc dl = getCurSDLoc(); +  EVT PtrVT = Ptr.getValueType(); +  unsigned Alignment = I.getAlignment(); +  AAMDNodes AAInfo; +  I.getAAMetadata(AAInfo); + +  auto MMOFlags = MachineMemOperand::MONone; +  if (I.isVolatile()) +    MMOFlags |= MachineMemOperand::MOVolatile; +  if (I.getMetadata(LLVMContext::MD_nontemporal) != nullptr) +    MMOFlags |= MachineMemOperand::MONonTemporal; + +  // An aggregate load cannot wrap around the address space, so offsets to its +  // parts don't wrap either. +  SDNodeFlags Flags; +  Flags.setNoUnsignedWrap(true); + +  unsigned ChainI = 0; +  for (unsigned i = 0; i != NumValues; ++i, ++ChainI) { +    // See visitLoad comments. +    if (ChainI == MaxParallelChains) { +      SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, +                                  makeArrayRef(Chains.data(), ChainI)); +      Root = Chain; +      ChainI = 0; +    } +    SDValue Add = DAG.getNode(ISD::ADD, dl, PtrVT, Ptr, +                              DAG.getConstant(Offsets[i], dl, PtrVT), Flags); +    SDValue St = DAG.getStore( +        Root, dl, SDValue(Src.getNode(), Src.getResNo() + i), Add, +        MachinePointerInfo(PtrV, Offsets[i]), Alignment, MMOFlags, AAInfo); +    Chains[ChainI] = St; +  } + +  SDValue StoreNode = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, +                                  makeArrayRef(Chains.data(), ChainI)); +  DAG.setRoot(StoreNode); +} + +void SelectionDAGBuilder::visitMaskedStore(const CallInst &I, +                                           bool IsCompressing) { +  SDLoc sdl = getCurSDLoc(); + +  auto getMaskedStoreOps = [&](Value* &Ptr, Value* &Mask, Value* &Src0, +                           unsigned& Alignment) { +    // llvm.masked.store.*(Src0, Ptr, alignment, Mask) +    Src0 = I.getArgOperand(0); +    Ptr = I.getArgOperand(1); +    Alignment = cast<ConstantInt>(I.getArgOperand(2))->getZExtValue(); +    Mask = I.getArgOperand(3); +  }; +  auto getCompressingStoreOps = [&](Value* &Ptr, Value* &Mask, Value* &Src0, +                           unsigned& Alignment) { +    // llvm.masked.compressstore.*(Src0, Ptr, Mask) +    Src0 = I.getArgOperand(0); +    Ptr = I.getArgOperand(1); +    Mask = I.getArgOperand(2); +    Alignment = 0; +  }; + +  Value  *PtrOperand, *MaskOperand, *Src0Operand; +  unsigned Alignment; +  if (IsCompressing) +    getCompressingStoreOps(PtrOperand, MaskOperand, Src0Operand, Alignment); +  else +    getMaskedStoreOps(PtrOperand, MaskOperand, Src0Operand, Alignment); + +  SDValue Ptr = getValue(PtrOperand); +  SDValue Src0 = getValue(Src0Operand); +  SDValue Mask = getValue(MaskOperand); + +  EVT VT = Src0.getValueType(); +  if (!Alignment) +    Alignment = DAG.getEVTAlignment(VT); + +  AAMDNodes AAInfo; +  I.getAAMetadata(AAInfo); + +  MachineMemOperand *MMO = +    DAG.getMachineFunction(). +    getMachineMemOperand(MachinePointerInfo(PtrOperand), +                          MachineMemOperand::MOStore,  VT.getStoreSize(), +                          Alignment, AAInfo); +  SDValue StoreNode = DAG.getMaskedStore(getRoot(), sdl, Src0, Ptr, Mask, VT, +                                         MMO, false /* Truncating */, +                                         IsCompressing); +  DAG.setRoot(StoreNode); +  setValue(&I, StoreNode); +} + +// Get a uniform base for the Gather/Scatter intrinsic. +// The first argument of the Gather/Scatter intrinsic is a vector of pointers. +// We try to represent it as a base pointer + vector of indices. +// Usually, the vector of pointers comes from a 'getelementptr' instruction. +// The first operand of the GEP may be a single pointer or a vector of pointers +// Example: +//   %gep.ptr = getelementptr i32, <8 x i32*> %vptr, <8 x i32> %ind +//  or +//   %gep.ptr = getelementptr i32, i32* %ptr,        <8 x i32> %ind +// %res = call <8 x i32> @llvm.masked.gather.v8i32(<8 x i32*> %gep.ptr, .. +// +// When the first GEP operand is a single pointer - it is the uniform base we +// are looking for. If first operand of the GEP is a splat vector - we +// extract the spalt value and use it as a uniform base. +// In all other cases the function returns 'false'. +// +static bool getUniformBase(const Value* &Ptr, SDValue& Base, SDValue& Index, +                           SelectionDAGBuilder* SDB) { + +  SelectionDAG& DAG = SDB->DAG; +  LLVMContext &Context = *DAG.getContext(); + +  assert(Ptr->getType()->isVectorTy() && "Uexpected pointer type"); +  const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr); +  if (!GEP || GEP->getNumOperands() > 2) +    return false; + +  const Value *GEPPtr = GEP->getPointerOperand(); +  if (!GEPPtr->getType()->isVectorTy()) +    Ptr = GEPPtr; +  else if (!(Ptr = getSplatValue(GEPPtr))) +    return false; + +  Value *IndexVal = GEP->getOperand(1); + +  // The operands of the GEP may be defined in another basic block. +  // In this case we'll not find nodes for the operands. +  if (!SDB->findValue(Ptr) || !SDB->findValue(IndexVal)) +    return false; + +  Base = SDB->getValue(Ptr); +  Index = SDB->getValue(IndexVal); + +  // Suppress sign extension. +  if (SExtInst* Sext = dyn_cast<SExtInst>(IndexVal)) { +    if (SDB->findValue(Sext->getOperand(0))) { +      IndexVal = Sext->getOperand(0); +      Index = SDB->getValue(IndexVal); +    } +  } +  if (!Index.getValueType().isVector()) { +    unsigned GEPWidth = GEP->getType()->getVectorNumElements(); +    EVT VT = EVT::getVectorVT(Context, Index.getValueType(), GEPWidth); +    Index = DAG.getSplatBuildVector(VT, SDLoc(Index), Index); +  } +  return true; +} + +void SelectionDAGBuilder::visitMaskedScatter(const CallInst &I) { +  SDLoc sdl = getCurSDLoc(); + +  // llvm.masked.scatter.*(Src0, Ptrs, alignemt, Mask) +  const Value *Ptr = I.getArgOperand(1); +  SDValue Src0 = getValue(I.getArgOperand(0)); +  SDValue Mask = getValue(I.getArgOperand(3)); +  EVT VT = Src0.getValueType(); +  unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(2)))->getZExtValue(); +  if (!Alignment) +    Alignment = DAG.getEVTAlignment(VT); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); + +  AAMDNodes AAInfo; +  I.getAAMetadata(AAInfo); + +  SDValue Base; +  SDValue Index; +  const Value *BasePtr = Ptr; +  bool UniformBase = getUniformBase(BasePtr, Base, Index, this); + +  const Value *MemOpBasePtr = UniformBase ? BasePtr : nullptr; +  MachineMemOperand *MMO = DAG.getMachineFunction(). +    getMachineMemOperand(MachinePointerInfo(MemOpBasePtr), +                         MachineMemOperand::MOStore,  VT.getStoreSize(), +                         Alignment, AAInfo); +  if (!UniformBase) { +    Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy(DAG.getDataLayout())); +    Index = getValue(Ptr); +  } +  SDValue Ops[] = { getRoot(), Src0, Mask, Base, Index }; +  SDValue Scatter = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), VT, sdl, +                                         Ops, MMO); +  DAG.setRoot(Scatter); +  setValue(&I, Scatter); +} + +void SelectionDAGBuilder::visitMaskedLoad(const CallInst &I, bool IsExpanding) { +  SDLoc sdl = getCurSDLoc(); + +  auto getMaskedLoadOps = [&](Value* &Ptr, Value* &Mask, Value* &Src0, +                           unsigned& Alignment) { +    // @llvm.masked.load.*(Ptr, alignment, Mask, Src0) +    Ptr = I.getArgOperand(0); +    Alignment = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue(); +    Mask = I.getArgOperand(2); +    Src0 = I.getArgOperand(3); +  }; +  auto getExpandingLoadOps = [&](Value* &Ptr, Value* &Mask, Value* &Src0, +                           unsigned& Alignment) { +    // @llvm.masked.expandload.*(Ptr, Mask, Src0) +    Ptr = I.getArgOperand(0); +    Alignment = 0; +    Mask = I.getArgOperand(1); +    Src0 = I.getArgOperand(2); +  }; + +  Value  *PtrOperand, *MaskOperand, *Src0Operand; +  unsigned Alignment; +  if (IsExpanding) +    getExpandingLoadOps(PtrOperand, MaskOperand, Src0Operand, Alignment); +  else +    getMaskedLoadOps(PtrOperand, MaskOperand, Src0Operand, Alignment); + +  SDValue Ptr = getValue(PtrOperand); +  SDValue Src0 = getValue(Src0Operand); +  SDValue Mask = getValue(MaskOperand); + +  EVT VT = Src0.getValueType(); +  if (!Alignment) +    Alignment = DAG.getEVTAlignment(VT); + +  AAMDNodes AAInfo; +  I.getAAMetadata(AAInfo); +  const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range); + +  // Do not serialize masked loads of constant memory with anything. +  bool AddToChain = !AA || !AA->pointsToConstantMemory(MemoryLocation( +      PtrOperand, DAG.getDataLayout().getTypeStoreSize(I.getType()), AAInfo)); +  SDValue InChain = AddToChain ? DAG.getRoot() : DAG.getEntryNode(); + +  MachineMemOperand *MMO = +    DAG.getMachineFunction(). +    getMachineMemOperand(MachinePointerInfo(PtrOperand), +                          MachineMemOperand::MOLoad,  VT.getStoreSize(), +                          Alignment, AAInfo, Ranges); + +  SDValue Load = DAG.getMaskedLoad(VT, sdl, InChain, Ptr, Mask, Src0, VT, MMO, +                                   ISD::NON_EXTLOAD, IsExpanding); +  if (AddToChain) { +    SDValue OutChain = Load.getValue(1); +    DAG.setRoot(OutChain); +  } +  setValue(&I, Load); +} + +void SelectionDAGBuilder::visitMaskedGather(const CallInst &I) { +  SDLoc sdl = getCurSDLoc(); + +  // @llvm.masked.gather.*(Ptrs, alignment, Mask, Src0) +  const Value *Ptr = I.getArgOperand(0); +  SDValue Src0 = getValue(I.getArgOperand(3)); +  SDValue Mask = getValue(I.getArgOperand(2)); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); +  unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(1)))->getZExtValue(); +  if (!Alignment) +    Alignment = DAG.getEVTAlignment(VT); + +  AAMDNodes AAInfo; +  I.getAAMetadata(AAInfo); +  const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range); + +  SDValue Root = DAG.getRoot(); +  SDValue Base; +  SDValue Index; +  const Value *BasePtr = Ptr; +  bool UniformBase = getUniformBase(BasePtr, Base, Index, this); +  bool ConstantMemory = false; +  if (UniformBase && +      AA && AA->pointsToConstantMemory(MemoryLocation( +          BasePtr, DAG.getDataLayout().getTypeStoreSize(I.getType()), +          AAInfo))) { +    // Do not serialize (non-volatile) loads of constant memory with anything. +    Root = DAG.getEntryNode(); +    ConstantMemory = true; +  } + +  MachineMemOperand *MMO = +    DAG.getMachineFunction(). +    getMachineMemOperand(MachinePointerInfo(UniformBase ? BasePtr : nullptr), +                         MachineMemOperand::MOLoad,  VT.getStoreSize(), +                         Alignment, AAInfo, Ranges); + +  if (!UniformBase) { +    Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy(DAG.getDataLayout())); +    Index = getValue(Ptr); +  } +  SDValue Ops[] = { Root, Src0, Mask, Base, Index }; +  SDValue Gather = DAG.getMaskedGather(DAG.getVTList(VT, MVT::Other), VT, sdl, +                                       Ops, MMO); + +  SDValue OutChain = Gather.getValue(1); +  if (!ConstantMemory) +    PendingLoads.push_back(OutChain); +  setValue(&I, Gather); +} + +void SelectionDAGBuilder::visitAtomicCmpXchg(const AtomicCmpXchgInst &I) { +  SDLoc dl = getCurSDLoc(); +  AtomicOrdering SuccessOrder = I.getSuccessOrdering(); +  AtomicOrdering FailureOrder = I.getFailureOrdering(); +  SynchronizationScope Scope = I.getSynchScope(); + +  SDValue InChain = getRoot(); + +  MVT MemVT = getValue(I.getCompareOperand()).getSimpleValueType(); +  SDVTList VTs = DAG.getVTList(MemVT, MVT::i1, MVT::Other); +  SDValue L = DAG.getAtomicCmpSwap( +      ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, dl, MemVT, VTs, InChain, +      getValue(I.getPointerOperand()), getValue(I.getCompareOperand()), +      getValue(I.getNewValOperand()), MachinePointerInfo(I.getPointerOperand()), +      /*Alignment=*/ 0, SuccessOrder, FailureOrder, Scope); + +  SDValue OutChain = L.getValue(2); + +  setValue(&I, L); +  DAG.setRoot(OutChain); +} + +void SelectionDAGBuilder::visitAtomicRMW(const AtomicRMWInst &I) { +  SDLoc dl = getCurSDLoc(); +  ISD::NodeType NT; +  switch (I.getOperation()) { +  default: llvm_unreachable("Unknown atomicrmw operation"); +  case AtomicRMWInst::Xchg: NT = ISD::ATOMIC_SWAP; break; +  case AtomicRMWInst::Add:  NT = ISD::ATOMIC_LOAD_ADD; break; +  case AtomicRMWInst::Sub:  NT = ISD::ATOMIC_LOAD_SUB; break; +  case AtomicRMWInst::And:  NT = ISD::ATOMIC_LOAD_AND; break; +  case AtomicRMWInst::Nand: NT = ISD::ATOMIC_LOAD_NAND; break; +  case AtomicRMWInst::Or:   NT = ISD::ATOMIC_LOAD_OR; break; +  case AtomicRMWInst::Xor:  NT = ISD::ATOMIC_LOAD_XOR; break; +  case AtomicRMWInst::Max:  NT = ISD::ATOMIC_LOAD_MAX; break; +  case AtomicRMWInst::Min:  NT = ISD::ATOMIC_LOAD_MIN; break; +  case AtomicRMWInst::UMax: NT = ISD::ATOMIC_LOAD_UMAX; break; +  case AtomicRMWInst::UMin: NT = ISD::ATOMIC_LOAD_UMIN; break; +  } +  AtomicOrdering Order = I.getOrdering(); +  SynchronizationScope Scope = I.getSynchScope(); + +  SDValue InChain = getRoot(); + +  SDValue L = +    DAG.getAtomic(NT, dl, +                  getValue(I.getValOperand()).getSimpleValueType(), +                  InChain, +                  getValue(I.getPointerOperand()), +                  getValue(I.getValOperand()), +                  I.getPointerOperand(), +                  /* Alignment=*/ 0, Order, Scope); + +  SDValue OutChain = L.getValue(1); + +  setValue(&I, L); +  DAG.setRoot(OutChain); +} + +void SelectionDAGBuilder::visitFence(const FenceInst &I) { +  SDLoc dl = getCurSDLoc(); +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue Ops[3]; +  Ops[0] = getRoot(); +  Ops[1] = DAG.getConstant((unsigned)I.getOrdering(), dl, +                           TLI.getFenceOperandTy(DAG.getDataLayout())); +  Ops[2] = DAG.getConstant(I.getSynchScope(), dl, +                           TLI.getFenceOperandTy(DAG.getDataLayout())); +  DAG.setRoot(DAG.getNode(ISD::ATOMIC_FENCE, dl, MVT::Other, Ops)); +} + +void SelectionDAGBuilder::visitAtomicLoad(const LoadInst &I) { +  SDLoc dl = getCurSDLoc(); +  AtomicOrdering Order = I.getOrdering(); +  SynchronizationScope Scope = I.getSynchScope(); + +  SDValue InChain = getRoot(); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); + +  if (I.getAlignment() < VT.getSizeInBits() / 8) +    report_fatal_error("Cannot generate unaligned atomic load"); + +  MachineMemOperand *MMO = +      DAG.getMachineFunction(). +      getMachineMemOperand(MachinePointerInfo(I.getPointerOperand()), +                           MachineMemOperand::MOVolatile | +                           MachineMemOperand::MOLoad, +                           VT.getStoreSize(), +                           I.getAlignment() ? I.getAlignment() : +                                              DAG.getEVTAlignment(VT), +                           AAMDNodes(), nullptr, Scope, Order); + +  InChain = TLI.prepareVolatileOrAtomicLoad(InChain, dl, DAG); +  SDValue L = +      DAG.getAtomic(ISD::ATOMIC_LOAD, dl, VT, VT, InChain, +                    getValue(I.getPointerOperand()), MMO); + +  SDValue OutChain = L.getValue(1); + +  setValue(&I, L); +  DAG.setRoot(OutChain); +} + +void SelectionDAGBuilder::visitAtomicStore(const StoreInst &I) { +  SDLoc dl = getCurSDLoc(); + +  AtomicOrdering Order = I.getOrdering(); +  SynchronizationScope Scope = I.getSynchScope(); + +  SDValue InChain = getRoot(); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  EVT VT = +      TLI.getValueType(DAG.getDataLayout(), I.getValueOperand()->getType()); + +  if (I.getAlignment() < VT.getSizeInBits() / 8) +    report_fatal_error("Cannot generate unaligned atomic store"); + +  SDValue OutChain = +    DAG.getAtomic(ISD::ATOMIC_STORE, dl, VT, +                  InChain, +                  getValue(I.getPointerOperand()), +                  getValue(I.getValueOperand()), +                  I.getPointerOperand(), I.getAlignment(), +                  Order, Scope); + +  DAG.setRoot(OutChain); +} + +/// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC +/// node. +void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I, +                                               unsigned Intrinsic) { +  // Ignore the callsite's attributes. A specific call site may be marked with +  // readnone, but the lowering code will expect the chain based on the +  // definition. +  const Function *F = I.getCalledFunction(); +  bool HasChain = !F->doesNotAccessMemory(); +  bool OnlyLoad = HasChain && F->onlyReadsMemory(); + +  // Build the operand list. +  SmallVector<SDValue, 8> Ops; +  if (HasChain) {  // If this intrinsic has side-effects, chainify it. +    if (OnlyLoad) { +      // We don't need to serialize loads against other loads. +      Ops.push_back(DAG.getRoot()); +    } else { +      Ops.push_back(getRoot()); +    } +  } + +  // Info is set by getTgtMemInstrinsic +  TargetLowering::IntrinsicInfo Info; +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  bool IsTgtIntrinsic = TLI.getTgtMemIntrinsic(Info, I, Intrinsic); + +  // Add the intrinsic ID as an integer operand if it's not a target intrinsic. +  if (!IsTgtIntrinsic || Info.opc == ISD::INTRINSIC_VOID || +      Info.opc == ISD::INTRINSIC_W_CHAIN) +    Ops.push_back(DAG.getTargetConstant(Intrinsic, getCurSDLoc(), +                                        TLI.getPointerTy(DAG.getDataLayout()))); + +  // Add all operands of the call to the operand list. +  for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) { +    SDValue Op = getValue(I.getArgOperand(i)); +    Ops.push_back(Op); +  } + +  SmallVector<EVT, 4> ValueVTs; +  ComputeValueVTs(TLI, DAG.getDataLayout(), I.getType(), ValueVTs); + +  if (HasChain) +    ValueVTs.push_back(MVT::Other); + +  SDVTList VTs = DAG.getVTList(ValueVTs); + +  // Create the node. +  SDValue Result; +  if (IsTgtIntrinsic) { +    // This is target intrinsic that touches memory +    Result = DAG.getMemIntrinsicNode(Info.opc, getCurSDLoc(), +                                     VTs, Ops, Info.memVT, +                                   MachinePointerInfo(Info.ptrVal, Info.offset), +                                     Info.align, Info.vol, +                                     Info.readMem, Info.writeMem, Info.size); +  } else if (!HasChain) { +    Result = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, getCurSDLoc(), VTs, Ops); +  } else if (!I.getType()->isVoidTy()) { +    Result = DAG.getNode(ISD::INTRINSIC_W_CHAIN, getCurSDLoc(), VTs, Ops); +  } else { +    Result = DAG.getNode(ISD::INTRINSIC_VOID, getCurSDLoc(), VTs, Ops); +  } + +  if (HasChain) { +    SDValue Chain = Result.getValue(Result.getNode()->getNumValues()-1); +    if (OnlyLoad) +      PendingLoads.push_back(Chain); +    else +      DAG.setRoot(Chain); +  } + +  if (!I.getType()->isVoidTy()) { +    if (VectorType *PTy = dyn_cast<VectorType>(I.getType())) { +      EVT VT = TLI.getValueType(DAG.getDataLayout(), PTy); +      Result = DAG.getNode(ISD::BITCAST, getCurSDLoc(), VT, Result); +    } else +      Result = lowerRangeToAssertZExt(DAG, I, Result); + +    setValue(&I, Result); +  } +} + +/// GetSignificand - Get the significand and build it into a floating-point +/// number with exponent of 1: +/// +///   Op = (Op & 0x007fffff) | 0x3f800000; +/// +/// where Op is the hexadecimal representation of floating point value. +static SDValue GetSignificand(SelectionDAG &DAG, SDValue Op, const SDLoc &dl) { +  SDValue t1 = DAG.getNode(ISD::AND, dl, MVT::i32, Op, +                           DAG.getConstant(0x007fffff, dl, MVT::i32)); +  SDValue t2 = DAG.getNode(ISD::OR, dl, MVT::i32, t1, +                           DAG.getConstant(0x3f800000, dl, MVT::i32)); +  return DAG.getNode(ISD::BITCAST, dl, MVT::f32, t2); +} + +/// GetExponent - Get the exponent: +/// +///   (float)(int)(((Op & 0x7f800000) >> 23) - 127); +/// +/// where Op is the hexadecimal representation of floating point value. +static SDValue GetExponent(SelectionDAG &DAG, SDValue Op, +                           const TargetLowering &TLI, const SDLoc &dl) { +  SDValue t0 = DAG.getNode(ISD::AND, dl, MVT::i32, Op, +                           DAG.getConstant(0x7f800000, dl, MVT::i32)); +  SDValue t1 = DAG.getNode( +      ISD::SRL, dl, MVT::i32, t0, +      DAG.getConstant(23, dl, TLI.getPointerTy(DAG.getDataLayout()))); +  SDValue t2 = DAG.getNode(ISD::SUB, dl, MVT::i32, t1, +                           DAG.getConstant(127, dl, MVT::i32)); +  return DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, t2); +} + +/// getF32Constant - Get 32-bit floating point constant. +static SDValue getF32Constant(SelectionDAG &DAG, unsigned Flt, +                              const SDLoc &dl) { +  return DAG.getConstantFP(APFloat(APFloat::IEEEsingle(), APInt(32, Flt)), dl, +                           MVT::f32); +} + +static SDValue getLimitedPrecisionExp2(SDValue t0, const SDLoc &dl, +                                       SelectionDAG &DAG) { +  // TODO: What fast-math-flags should be set on the floating-point nodes? + +  //   IntegerPartOfX = ((int32_t)(t0); +  SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, t0); + +  //   FractionalPartOfX = t0 - (float)IntegerPartOfX; +  SDValue t1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, IntegerPartOfX); +  SDValue X = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, t1); + +  //   IntegerPartOfX <<= 23; +  IntegerPartOfX = DAG.getNode( +      ISD::SHL, dl, MVT::i32, IntegerPartOfX, +      DAG.getConstant(23, dl, DAG.getTargetLoweringInfo().getPointerTy( +                                  DAG.getDataLayout()))); + +  SDValue TwoToFractionalPartOfX; +  if (LimitFloatPrecision <= 6) { +    // For floating-point precision of 6: +    // +    //   TwoToFractionalPartOfX = +    //     0.997535578f + +    //       (0.735607626f + 0.252464424f * x) * x; +    // +    // error 0.0144103317, which is 6 bits +    SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                             getF32Constant(DAG, 0x3e814304, dl)); +    SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, +                             getF32Constant(DAG, 0x3f3c50c8, dl)); +    SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +    TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, +                                         getF32Constant(DAG, 0x3f7f5e7e, dl)); +  } else if (LimitFloatPrecision <= 12) { +    // For floating-point precision of 12: +    // +    //   TwoToFractionalPartOfX = +    //     0.999892986f + +    //       (0.696457318f + +    //         (0.224338339f + 0.792043434e-1f * x) * x) * x; +    // +    // error 0.000107046256, which is 13 to 14 bits +    SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                             getF32Constant(DAG, 0x3da235e3, dl)); +    SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, +                             getF32Constant(DAG, 0x3e65b8f3, dl)); +    SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +    SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, +                             getF32Constant(DAG, 0x3f324b07, dl)); +    SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); +    TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t6, +                                         getF32Constant(DAG, 0x3f7ff8fd, dl)); +  } else { // LimitFloatPrecision <= 18 +    // For floating-point precision of 18: +    // +    //   TwoToFractionalPartOfX = +    //     0.999999982f + +    //       (0.693148872f + +    //         (0.240227044f + +    //           (0.554906021e-1f + +    //             (0.961591928e-2f + +    //               (0.136028312e-2f + 0.157059148e-3f *x)*x)*x)*x)*x)*x; +    // error 2.47208000*10^(-7), which is better than 18 bits +    SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                             getF32Constant(DAG, 0x3924b03e, dl)); +    SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, +                             getF32Constant(DAG, 0x3ab24b87, dl)); +    SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +    SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, +                             getF32Constant(DAG, 0x3c1d8c17, dl)); +    SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); +    SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6, +                             getF32Constant(DAG, 0x3d634a1d, dl)); +    SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); +    SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8, +                             getF32Constant(DAG, 0x3e75fe14, dl)); +    SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X); +    SDValue t11 = DAG.getNode(ISD::FADD, dl, MVT::f32, t10, +                              getF32Constant(DAG, 0x3f317234, dl)); +    SDValue t12 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t11, X); +    TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t12, +                                         getF32Constant(DAG, 0x3f800000, dl)); +  } + +  // Add the exponent into the result in integer domain. +  SDValue t13 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, TwoToFractionalPartOfX); +  return DAG.getNode(ISD::BITCAST, dl, MVT::f32, +                     DAG.getNode(ISD::ADD, dl, MVT::i32, t13, IntegerPartOfX)); +} + +/// expandExp - Lower an exp intrinsic. Handles the special sequences for +/// limited-precision mode. +static SDValue expandExp(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, +                         const TargetLowering &TLI) { +  if (Op.getValueType() == MVT::f32 && +      LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { + +    // Put the exponent in the right bit position for later addition to the +    // final result: +    // +    //   #define LOG2OFe 1.4426950f +    //   t0 = Op * LOG2OFe + +    // TODO: What fast-math-flags should be set here? +    SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, Op, +                             getF32Constant(DAG, 0x3fb8aa3b, dl)); +    return getLimitedPrecisionExp2(t0, dl, DAG); +  } + +  // No special expansion. +  return DAG.getNode(ISD::FEXP, dl, Op.getValueType(), Op); +} + +/// expandLog - Lower a log intrinsic. Handles the special sequences for +/// limited-precision mode. +static SDValue expandLog(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, +                         const TargetLowering &TLI) { + +  // TODO: What fast-math-flags should be set on the floating-point nodes? + +  if (Op.getValueType() == MVT::f32 && +      LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { +    SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); + +    // Scale the exponent by log(2) [0.69314718f]. +    SDValue Exp = GetExponent(DAG, Op1, TLI, dl); +    SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp, +                                        getF32Constant(DAG, 0x3f317218, dl)); + +    // Get the significand and build it into a floating-point number with +    // exponent of 1. +    SDValue X = GetSignificand(DAG, Op1, dl); + +    SDValue LogOfMantissa; +    if (LimitFloatPrecision <= 6) { +      // For floating-point precision of 6: +      // +      //   LogofMantissa = +      //     -1.1609546f + +      //       (1.4034025f - 0.23903021f * x) * x; +      // +      // error 0.0034276066, which is better than 8 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0xbe74c456, dl)); +      SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3fb3a2b1, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, +                                  getF32Constant(DAG, 0x3f949a29, dl)); +    } else if (LimitFloatPrecision <= 12) { +      // For floating-point precision of 12: +      // +      //   LogOfMantissa = +      //     -1.7417939f + +      //       (2.8212026f + +      //         (-1.4699568f + +      //           (0.44717955f - 0.56570851e-1f * x) * x) * x) * x; +      // +      // error 0.000061011436, which is 14 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0xbd67b6d6, dl)); +      SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3ee4f4b8, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, +                               getF32Constant(DAG, 0x3fbc278b, dl)); +      SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +      SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, +                               getF32Constant(DAG, 0x40348e95, dl)); +      SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); +      LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, +                                  getF32Constant(DAG, 0x3fdef31a, dl)); +    } else { // LimitFloatPrecision <= 18 +      // For floating-point precision of 18: +      // +      //   LogOfMantissa = +      //     -2.1072184f + +      //       (4.2372794f + +      //         (-3.7029485f + +      //           (2.2781945f + +      //             (-0.87823314f + +      //               (0.19073739f - 0.17809712e-1f * x) * x) * x) * x) * x)*x; +      // +      // error 0.0000023660568, which is better than 18 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0xbc91e5ac, dl)); +      SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3e4350aa, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, +                               getF32Constant(DAG, 0x3f60d3e3, dl)); +      SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +      SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, +                               getF32Constant(DAG, 0x4011cdf0, dl)); +      SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); +      SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, +                               getF32Constant(DAG, 0x406cfd1c, dl)); +      SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); +      SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8, +                               getF32Constant(DAG, 0x408797cb, dl)); +      SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X); +      LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10, +                                  getF32Constant(DAG, 0x4006dcab, dl)); +    } + +    return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, LogOfMantissa); +  } + +  // No special expansion. +  return DAG.getNode(ISD::FLOG, dl, Op.getValueType(), Op); +} + +/// expandLog2 - Lower a log2 intrinsic. Handles the special sequences for +/// limited-precision mode. +static SDValue expandLog2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, +                          const TargetLowering &TLI) { + +  // TODO: What fast-math-flags should be set on the floating-point nodes? + +  if (Op.getValueType() == MVT::f32 && +      LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { +    SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); + +    // Get the exponent. +    SDValue LogOfExponent = GetExponent(DAG, Op1, TLI, dl); + +    // Get the significand and build it into a floating-point number with +    // exponent of 1. +    SDValue X = GetSignificand(DAG, Op1, dl); + +    // Different possible minimax approximations of significand in +    // floating-point for various degrees of accuracy over [1,2]. +    SDValue Log2ofMantissa; +    if (LimitFloatPrecision <= 6) { +      // For floating-point precision of 6: +      // +      //   Log2ofMantissa = -1.6749035f + (2.0246817f - .34484768f * x) * x; +      // +      // error 0.0049451742, which is more than 7 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0xbeb08fe0, dl)); +      SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x40019463, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, +                                   getF32Constant(DAG, 0x3fd6633d, dl)); +    } else if (LimitFloatPrecision <= 12) { +      // For floating-point precision of 12: +      // +      //   Log2ofMantissa = +      //     -2.51285454f + +      //       (4.07009056f + +      //         (-2.12067489f + +      //           (.645142248f - 0.816157886e-1f * x) * x) * x) * x; +      // +      // error 0.0000876136000, which is better than 13 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0xbda7262e, dl)); +      SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3f25280b, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, +                               getF32Constant(DAG, 0x4007b923, dl)); +      SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +      SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, +                               getF32Constant(DAG, 0x40823e2f, dl)); +      SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); +      Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, +                                   getF32Constant(DAG, 0x4020d29c, dl)); +    } else { // LimitFloatPrecision <= 18 +      // For floating-point precision of 18: +      // +      //   Log2ofMantissa = +      //     -3.0400495f + +      //       (6.1129976f + +      //         (-5.3420409f + +      //           (3.2865683f + +      //             (-1.2669343f + +      //               (0.27515199f - +      //                 0.25691327e-1f * x) * x) * x) * x) * x) * x; +      // +      // error 0.0000018516, which is better than 18 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0xbcd2769e, dl)); +      SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3e8ce0b9, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, +                               getF32Constant(DAG, 0x3fa22ae7, dl)); +      SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +      SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4, +                               getF32Constant(DAG, 0x40525723, dl)); +      SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); +      SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6, +                               getF32Constant(DAG, 0x40aaf200, dl)); +      SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); +      SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8, +                               getF32Constant(DAG, 0x40c39dad, dl)); +      SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X); +      Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10, +                                   getF32Constant(DAG, 0x4042902c, dl)); +    } + +    return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log2ofMantissa); +  } + +  // No special expansion. +  return DAG.getNode(ISD::FLOG2, dl, Op.getValueType(), Op); +} + +/// expandLog10 - Lower a log10 intrinsic. Handles the special sequences for +/// limited-precision mode. +static SDValue expandLog10(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, +                           const TargetLowering &TLI) { + +  // TODO: What fast-math-flags should be set on the floating-point nodes? + +  if (Op.getValueType() == MVT::f32 && +      LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { +    SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op); + +    // Scale the exponent by log10(2) [0.30102999f]. +    SDValue Exp = GetExponent(DAG, Op1, TLI, dl); +    SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp, +                                        getF32Constant(DAG, 0x3e9a209a, dl)); + +    // Get the significand and build it into a floating-point number with +    // exponent of 1. +    SDValue X = GetSignificand(DAG, Op1, dl); + +    SDValue Log10ofMantissa; +    if (LimitFloatPrecision <= 6) { +      // For floating-point precision of 6: +      // +      //   Log10ofMantissa = +      //     -0.50419619f + +      //       (0.60948995f - 0.10380950f * x) * x; +      // +      // error 0.0014886165, which is 6 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0xbdd49a13, dl)); +      SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3f1c0789, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2, +                                    getF32Constant(DAG, 0x3f011300, dl)); +    } else if (LimitFloatPrecision <= 12) { +      // For floating-point precision of 12: +      // +      //   Log10ofMantissa = +      //     -0.64831180f + +      //       (0.91751397f + +      //         (-0.31664806f + 0.47637168e-1f * x) * x) * x; +      // +      // error 0.00019228036, which is better than 12 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0x3d431f31, dl)); +      SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3ea21fb2, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, +                               getF32Constant(DAG, 0x3f6ae232, dl)); +      SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +      Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4, +                                    getF32Constant(DAG, 0x3f25f7c3, dl)); +    } else { // LimitFloatPrecision <= 18 +      // For floating-point precision of 18: +      // +      //   Log10ofMantissa = +      //     -0.84299375f + +      //       (1.5327582f + +      //         (-1.0688956f + +      //           (0.49102474f + +      //             (-0.12539807f + 0.13508273e-1f * x) * x) * x) * x) * x; +      // +      // error 0.0000037995730, which is better than 18 bits +      SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X, +                               getF32Constant(DAG, 0x3c5d51ce, dl)); +      SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, +                               getF32Constant(DAG, 0x3e00685a, dl)); +      SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X); +      SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2, +                               getF32Constant(DAG, 0x3efb6798, dl)); +      SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X); +      SDValue t5 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4, +                               getF32Constant(DAG, 0x3f88d192, dl)); +      SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X); +      SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6, +                               getF32Constant(DAG, 0x3fc4316c, dl)); +      SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X); +      Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t8, +                                    getF32Constant(DAG, 0x3f57ce70, dl)); +    } + +    return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log10ofMantissa); +  } + +  // No special expansion. +  return DAG.getNode(ISD::FLOG10, dl, Op.getValueType(), Op); +} + +/// expandExp2 - Lower an exp2 intrinsic. Handles the special sequences for +/// limited-precision mode. +static SDValue expandExp2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG, +                          const TargetLowering &TLI) { +  if (Op.getValueType() == MVT::f32 && +      LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) +    return getLimitedPrecisionExp2(Op, dl, DAG); + +  // No special expansion. +  return DAG.getNode(ISD::FEXP2, dl, Op.getValueType(), Op); +} + +/// visitPow - Lower a pow intrinsic. Handles the special sequences for +/// limited-precision mode with x == 10.0f. +static SDValue expandPow(const SDLoc &dl, SDValue LHS, SDValue RHS, +                         SelectionDAG &DAG, const TargetLowering &TLI) { +  bool IsExp10 = false; +  if (LHS.getValueType() == MVT::f32 && RHS.getValueType() == MVT::f32 && +      LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) { +    if (ConstantFPSDNode *LHSC = dyn_cast<ConstantFPSDNode>(LHS)) { +      APFloat Ten(10.0f); +      IsExp10 = LHSC->isExactlyValue(Ten); +    } +  } + +  // TODO: What fast-math-flags should be set on the FMUL node? +  if (IsExp10) { +    // Put the exponent in the right bit position for later addition to the +    // final result: +    // +    //   #define LOG2OF10 3.3219281f +    //   t0 = Op * LOG2OF10; +    SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, RHS, +                             getF32Constant(DAG, 0x40549a78, dl)); +    return getLimitedPrecisionExp2(t0, dl, DAG); +  } + +  // No special expansion. +  return DAG.getNode(ISD::FPOW, dl, LHS.getValueType(), LHS, RHS); +} + + +/// ExpandPowI - Expand a llvm.powi intrinsic. +static SDValue ExpandPowI(const SDLoc &DL, SDValue LHS, SDValue RHS, +                          SelectionDAG &DAG) { +  // If RHS is a constant, we can expand this out to a multiplication tree, +  // otherwise we end up lowering to a call to __powidf2 (for example).  When +  // optimizing for size, we only want to do this if the expansion would produce +  // a small number of multiplies, otherwise we do the full expansion. +  if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS)) { +    // Get the exponent as a positive value. +    unsigned Val = RHSC->getSExtValue(); +    if ((int)Val < 0) Val = -Val; + +    // powi(x, 0) -> 1.0 +    if (Val == 0) +      return DAG.getConstantFP(1.0, DL, LHS.getValueType()); + +    const Function *F = DAG.getMachineFunction().getFunction(); +    if (!F->optForSize() || +        // If optimizing for size, don't insert too many multiplies. +        // This inserts up to 5 multiplies. +        countPopulation(Val) + Log2_32(Val) < 7) { +      // We use the simple binary decomposition method to generate the multiply +      // sequence.  There are more optimal ways to do this (for example, +      // powi(x,15) generates one more multiply than it should), but this has +      // the benefit of being both really simple and much better than a libcall. +      SDValue Res;  // Logically starts equal to 1.0 +      SDValue CurSquare = LHS; +      // TODO: Intrinsics should have fast-math-flags that propagate to these +      // nodes. +      while (Val) { +        if (Val & 1) { +          if (Res.getNode()) +            Res = DAG.getNode(ISD::FMUL, DL,Res.getValueType(), Res, CurSquare); +          else +            Res = CurSquare;  // 1.0*CurSquare. +        } + +        CurSquare = DAG.getNode(ISD::FMUL, DL, CurSquare.getValueType(), +                                CurSquare, CurSquare); +        Val >>= 1; +      } + +      // If the original was negative, invert the result, producing 1/(x*x*x). +      if (RHSC->getSExtValue() < 0) +        Res = DAG.getNode(ISD::FDIV, DL, LHS.getValueType(), +                          DAG.getConstantFP(1.0, DL, LHS.getValueType()), Res); +      return Res; +    } +  } + +  // Otherwise, expand to a libcall. +  return DAG.getNode(ISD::FPOWI, DL, LHS.getValueType(), LHS, RHS); +} + +// getUnderlyingArgReg - Find underlying register used for a truncated or +// bitcasted argument. +static unsigned getUnderlyingArgReg(const SDValue &N) { +  switch (N.getOpcode()) { +  case ISD::CopyFromReg: +    return cast<RegisterSDNode>(N.getOperand(1))->getReg(); +  case ISD::BITCAST: +  case ISD::AssertZext: +  case ISD::AssertSext: +  case ISD::TRUNCATE: +    return getUnderlyingArgReg(N.getOperand(0)); +  default: +    return 0; +  } +} + +/// EmitFuncArgumentDbgValue - If the DbgValueInst is a dbg_value of a function +/// argument, create the corresponding DBG_VALUE machine instruction for it now. +/// At the end of instruction selection, they will be inserted to the entry BB. +bool SelectionDAGBuilder::EmitFuncArgumentDbgValue( +    const Value *V, DILocalVariable *Variable, DIExpression *Expr, +    DILocation *DL, int64_t Offset, bool IsDbgDeclare, const SDValue &N) { +  const Argument *Arg = dyn_cast<Argument>(V); +  if (!Arg) +    return false; + +  MachineFunction &MF = DAG.getMachineFunction(); +  const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo(); + +  // Ignore inlined function arguments here. +  // +  // FIXME: Should we be checking DL->inlinedAt() to determine this? +  if (!Variable->getScope()->getSubprogram()->describes(MF.getFunction())) +    return false; + +  bool IsIndirect = false; +  Optional<MachineOperand> Op; +  // Some arguments' frame index is recorded during argument lowering. +  int FI = FuncInfo.getArgumentFrameIndex(Arg); +  if (FI != INT_MAX) +    Op = MachineOperand::CreateFI(FI); + +  if (!Op && N.getNode()) { +    unsigned Reg = getUnderlyingArgReg(N); +    if (Reg && TargetRegisterInfo::isVirtualRegister(Reg)) { +      MachineRegisterInfo &RegInfo = MF.getRegInfo(); +      unsigned PR = RegInfo.getLiveInPhysReg(Reg); +      if (PR) +        Reg = PR; +    } +    if (Reg) { +      Op = MachineOperand::CreateReg(Reg, false); +      IsIndirect = IsDbgDeclare; +    } +  } + +  if (!Op) { +    // Check if ValueMap has reg number. +    DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V); +    if (VMI != FuncInfo.ValueMap.end()) { +      Op = MachineOperand::CreateReg(VMI->second, false); +      IsIndirect = IsDbgDeclare; +    } +  } + +  if (!Op && N.getNode()) +    // Check if frame index is available. +    if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(N.getNode())) +      if (FrameIndexSDNode *FINode = +          dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode())) +        Op = MachineOperand::CreateFI(FINode->getIndex()); + +  if (!Op) +    return false; + +  assert(Variable->isValidLocationForIntrinsic(DL) && +         "Expected inlined-at fields to agree"); +  if (Op->isReg()) +    FuncInfo.ArgDbgValues.push_back( +        BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsIndirect, +                Op->getReg(), Offset, Variable, Expr)); +  else +    FuncInfo.ArgDbgValues.push_back( +        BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE)) +            .add(*Op) +            .addImm(Offset) +            .addMetadata(Variable) +            .addMetadata(Expr)); + +  return true; +} + +/// Return the appropriate SDDbgValue based on N. +SDDbgValue *SelectionDAGBuilder::getDbgValue(SDValue N, +                                             DILocalVariable *Variable, +                                             DIExpression *Expr, int64_t Offset, +                                             const DebugLoc &dl, +                                             unsigned DbgSDNodeOrder) { +  if (auto *FISDN = dyn_cast<FrameIndexSDNode>(N.getNode())) { +    // Construct a FrameIndexDbgValue for FrameIndexSDNodes so we can describe +    // stack slot locations as such instead of as indirectly addressed +    // locations. +    return DAG.getFrameIndexDbgValue(Variable, Expr, FISDN->getIndex(), 0, dl, +                                     DbgSDNodeOrder); +  } +  return DAG.getDbgValue(Variable, Expr, N.getNode(), N.getResNo(), false, +                         Offset, dl, DbgSDNodeOrder); +} + +// VisualStudio defines setjmp as _setjmp +#if defined(_MSC_VER) && defined(setjmp) && \ +                         !defined(setjmp_undefined_for_msvc) +#  pragma push_macro("setjmp") +#  undef setjmp +#  define setjmp_undefined_for_msvc +#endif + +/// Lower the call to the specified intrinsic function. If we want to emit this +/// as a call to a named external function, return the name. Otherwise, lower it +/// and return null. +const char * +SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDLoc sdl = getCurSDLoc(); +  DebugLoc dl = getCurDebugLoc(); +  SDValue Res; + +  switch (Intrinsic) { +  default: +    // By default, turn this into a target intrinsic node. +    visitTargetIntrinsic(I, Intrinsic); +    return nullptr; +  case Intrinsic::vastart:  visitVAStart(I); return nullptr; +  case Intrinsic::vaend:    visitVAEnd(I); return nullptr; +  case Intrinsic::vacopy:   visitVACopy(I); return nullptr; +  case Intrinsic::returnaddress: +    setValue(&I, DAG.getNode(ISD::RETURNADDR, sdl, +                             TLI.getPointerTy(DAG.getDataLayout()), +                             getValue(I.getArgOperand(0)))); +    return nullptr; +  case Intrinsic::addressofreturnaddress: +    setValue(&I, DAG.getNode(ISD::ADDROFRETURNADDR, sdl, +                             TLI.getPointerTy(DAG.getDataLayout()))); +    return nullptr; +  case Intrinsic::frameaddress: +    setValue(&I, DAG.getNode(ISD::FRAMEADDR, sdl, +                             TLI.getPointerTy(DAG.getDataLayout()), +                             getValue(I.getArgOperand(0)))); +    return nullptr; +  case Intrinsic::read_register: { +    Value *Reg = I.getArgOperand(0); +    SDValue Chain = getRoot(); +    SDValue RegName = +        DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata())); +    EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); +    Res = DAG.getNode(ISD::READ_REGISTER, sdl, +      DAG.getVTList(VT, MVT::Other), Chain, RegName); +    setValue(&I, Res); +    DAG.setRoot(Res.getValue(1)); +    return nullptr; +  } +  case Intrinsic::write_register: { +    Value *Reg = I.getArgOperand(0); +    Value *RegValue = I.getArgOperand(1); +    SDValue Chain = getRoot(); +    SDValue RegName = +        DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata())); +    DAG.setRoot(DAG.getNode(ISD::WRITE_REGISTER, sdl, MVT::Other, Chain, +                            RegName, getValue(RegValue))); +    return nullptr; +  } +  case Intrinsic::setjmp: +    return &"_setjmp"[!TLI.usesUnderscoreSetJmp()]; +  case Intrinsic::longjmp: +    return &"_longjmp"[!TLI.usesUnderscoreLongJmp()]; +  case Intrinsic::memcpy: { +    SDValue Op1 = getValue(I.getArgOperand(0)); +    SDValue Op2 = getValue(I.getArgOperand(1)); +    SDValue Op3 = getValue(I.getArgOperand(2)); +    unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue(); +    if (!Align) +      Align = 1; // @llvm.memcpy defines 0 and 1 to both mean no alignment. +    bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue(); +    bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget()); +    SDValue MC = DAG.getMemcpy(getRoot(), sdl, Op1, Op2, Op3, Align, isVol, +                               false, isTC, +                               MachinePointerInfo(I.getArgOperand(0)), +                               MachinePointerInfo(I.getArgOperand(1))); +    updateDAGForMaybeTailCall(MC); +    return nullptr; +  } +  case Intrinsic::memset: { +    SDValue Op1 = getValue(I.getArgOperand(0)); +    SDValue Op2 = getValue(I.getArgOperand(1)); +    SDValue Op3 = getValue(I.getArgOperand(2)); +    unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue(); +    if (!Align) +      Align = 1; // @llvm.memset defines 0 and 1 to both mean no alignment. +    bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue(); +    bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget()); +    SDValue MS = DAG.getMemset(getRoot(), sdl, Op1, Op2, Op3, Align, isVol, +                               isTC, MachinePointerInfo(I.getArgOperand(0))); +    updateDAGForMaybeTailCall(MS); +    return nullptr; +  } +  case Intrinsic::memmove: { +    SDValue Op1 = getValue(I.getArgOperand(0)); +    SDValue Op2 = getValue(I.getArgOperand(1)); +    SDValue Op3 = getValue(I.getArgOperand(2)); +    unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue(); +    if (!Align) +      Align = 1; // @llvm.memmove defines 0 and 1 to both mean no alignment. +    bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue(); +    bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget()); +    SDValue MM = DAG.getMemmove(getRoot(), sdl, Op1, Op2, Op3, Align, isVol, +                                isTC, MachinePointerInfo(I.getArgOperand(0)), +                                MachinePointerInfo(I.getArgOperand(1))); +    updateDAGForMaybeTailCall(MM); +    return nullptr; +  } +  case Intrinsic::memcpy_element_unordered_atomic: { +    const ElementUnorderedAtomicMemCpyInst &MI = +        cast<ElementUnorderedAtomicMemCpyInst>(I); +    SDValue Dst = getValue(MI.getRawDest()); +    SDValue Src = getValue(MI.getRawSource()); +    SDValue Length = getValue(MI.getLength()); + +    // Emit a library call. +    TargetLowering::ArgListTy Args; +    TargetLowering::ArgListEntry Entry; +    Entry.Ty = DAG.getDataLayout().getIntPtrType(*DAG.getContext()); +    Entry.Node = Dst; +    Args.push_back(Entry); + +    Entry.Node = Src; +    Args.push_back(Entry); + +    Entry.Ty = MI.getLength()->getType(); +    Entry.Node = Length; +    Args.push_back(Entry); + +    uint64_t ElementSizeConstant = MI.getElementSizeInBytes(); +    RTLIB::Libcall LibraryCall = +        RTLIB::getMEMCPY_ELEMENT_UNORDERED_ATOMIC(ElementSizeConstant); +    if (LibraryCall == RTLIB::UNKNOWN_LIBCALL) +      report_fatal_error("Unsupported element size"); + +    TargetLowering::CallLoweringInfo CLI(DAG); +    CLI.setDebugLoc(sdl).setChain(getRoot()).setLibCallee( +        TLI.getLibcallCallingConv(LibraryCall), +        Type::getVoidTy(*DAG.getContext()), +        DAG.getExternalSymbol(TLI.getLibcallName(LibraryCall), +                              TLI.getPointerTy(DAG.getDataLayout())), +        std::move(Args)); + +    std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI); +    DAG.setRoot(CallResult.second); +    return nullptr; +  } +  case Intrinsic::dbg_declare: { +    const DbgDeclareInst &DI = cast<DbgDeclareInst>(I); +    DILocalVariable *Variable = DI.getVariable(); +    DIExpression *Expression = DI.getExpression(); +    const Value *Address = DI.getAddress(); +    assert(Variable && "Missing variable"); +    if (!Address) { +      DEBUG(dbgs() << "Dropping debug info for " << DI << "\n"); +      return nullptr; +    } + +    // Check if address has undef value. +    if (isa<UndefValue>(Address) || +        (Address->use_empty() && !isa<Argument>(Address))) { +      DEBUG(dbgs() << "Dropping debug info for " << DI << "\n"); +      return nullptr; +    } + +    // Byval arguments with frame indices were already handled after argument +    // lowering and before isel. +    const auto *Arg = +        dyn_cast<Argument>(Address->stripInBoundsConstantOffsets()); +    if (Arg && FuncInfo.getArgumentFrameIndex(Arg) != INT_MAX) +      return nullptr; + +    SDValue &N = NodeMap[Address]; +    if (!N.getNode() && isa<Argument>(Address)) +      // Check unused arguments map. +      N = UnusedArgNodeMap[Address]; +    SDDbgValue *SDV; +    if (N.getNode()) { +      if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address)) +        Address = BCI->getOperand(0); +      // Parameters are handled specially. +      bool isParameter = Variable->isParameter() || isa<Argument>(Address); +      auto FINode = dyn_cast<FrameIndexSDNode>(N.getNode()); +      if (isParameter && FINode) { +        // Byval parameter. We have a frame index at this point. +        SDV = DAG.getFrameIndexDbgValue(Variable, Expression, +                                        FINode->getIndex(), 0, dl, SDNodeOrder); +      } else if (isa<Argument>(Address)) { +        // Address is an argument, so try to emit its dbg value using +        // virtual register info from the FuncInfo.ValueMap. +        EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, true, N); +        return nullptr; +      } else { +        SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(), +                              true, 0, dl, SDNodeOrder); +      } +      DAG.AddDbgValue(SDV, N.getNode(), isParameter); +    } else { +      // If Address is an argument then try to emit its dbg value using +      // virtual register info from the FuncInfo.ValueMap. +      if (!EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, true, +                                    N)) { +        DEBUG(dbgs() << "Dropping debug info for " << DI << "\n"); +      } +    } +    return nullptr; +  } +  case Intrinsic::dbg_value: { +    const DbgValueInst &DI = cast<DbgValueInst>(I); +    assert(DI.getVariable() && "Missing variable"); + +    DILocalVariable *Variable = DI.getVariable(); +    DIExpression *Expression = DI.getExpression(); +    uint64_t Offset = DI.getOffset(); +    const Value *V = DI.getValue(); +    if (!V) +      return nullptr; + +    SDDbgValue *SDV; +    if (isa<ConstantInt>(V) || isa<ConstantFP>(V) || isa<UndefValue>(V)) { +      SDV = DAG.getConstantDbgValue(Variable, Expression, V, Offset, dl, +                                    SDNodeOrder); +      DAG.AddDbgValue(SDV, nullptr, false); +      return nullptr; +    } + +    // Do not use getValue() in here; we don't want to generate code at +    // this point if it hasn't been done yet. +    SDValue N = NodeMap[V]; +    if (!N.getNode() && isa<Argument>(V)) // Check unused arguments map. +      N = UnusedArgNodeMap[V]; +    if (N.getNode()) { +      if (EmitFuncArgumentDbgValue(V, Variable, Expression, dl, Offset, false, +                                   N)) +        return nullptr; +      SDV = getDbgValue(N, Variable, Expression, Offset, dl, SDNodeOrder); +      DAG.AddDbgValue(SDV, N.getNode(), false); +      return nullptr; +    } + +    if (!V->use_empty() ) { +      // Do not call getValue(V) yet, as we don't want to generate code. +      // Remember it for later. +      DanglingDebugInfo DDI(&DI, dl, SDNodeOrder); +      DanglingDebugInfoMap[V] = DDI; +      return nullptr; +    } + +    DEBUG(dbgs() << "Dropping debug location info for:\n  " << DI << "\n"); +    DEBUG(dbgs() << "  Last seen at:\n    " << *V << "\n"); +    return nullptr; +  } + +  case Intrinsic::eh_typeid_for: { +    // Find the type id for the given typeinfo. +    GlobalValue *GV = ExtractTypeInfo(I.getArgOperand(0)); +    unsigned TypeID = DAG.getMachineFunction().getTypeIDFor(GV); +    Res = DAG.getConstant(TypeID, sdl, MVT::i32); +    setValue(&I, Res); +    return nullptr; +  } + +  case Intrinsic::eh_return_i32: +  case Intrinsic::eh_return_i64: +    DAG.getMachineFunction().setCallsEHReturn(true); +    DAG.setRoot(DAG.getNode(ISD::EH_RETURN, sdl, +                            MVT::Other, +                            getControlRoot(), +                            getValue(I.getArgOperand(0)), +                            getValue(I.getArgOperand(1)))); +    return nullptr; +  case Intrinsic::eh_unwind_init: +    DAG.getMachineFunction().setCallsUnwindInit(true); +    return nullptr; +  case Intrinsic::eh_dwarf_cfa: { +    setValue(&I, DAG.getNode(ISD::EH_DWARF_CFA, sdl, +                             TLI.getPointerTy(DAG.getDataLayout()), +                             getValue(I.getArgOperand(0)))); +    return nullptr; +  } +  case Intrinsic::eh_sjlj_callsite: { +    MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI(); +    ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(0)); +    assert(CI && "Non-constant call site value in eh.sjlj.callsite!"); +    assert(MMI.getCurrentCallSite() == 0 && "Overlapping call sites!"); + +    MMI.setCurrentCallSite(CI->getZExtValue()); +    return nullptr; +  } +  case Intrinsic::eh_sjlj_functioncontext: { +    // Get and store the index of the function context. +    MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo(); +    AllocaInst *FnCtx = +      cast<AllocaInst>(I.getArgOperand(0)->stripPointerCasts()); +    int FI = FuncInfo.StaticAllocaMap[FnCtx]; +    MFI.setFunctionContextIndex(FI); +    return nullptr; +  } +  case Intrinsic::eh_sjlj_setjmp: { +    SDValue Ops[2]; +    Ops[0] = getRoot(); +    Ops[1] = getValue(I.getArgOperand(0)); +    SDValue Op = DAG.getNode(ISD::EH_SJLJ_SETJMP, sdl, +                             DAG.getVTList(MVT::i32, MVT::Other), Ops); +    setValue(&I, Op.getValue(0)); +    DAG.setRoot(Op.getValue(1)); +    return nullptr; +  } +  case Intrinsic::eh_sjlj_longjmp: { +    DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_LONGJMP, sdl, MVT::Other, +                            getRoot(), getValue(I.getArgOperand(0)))); +    return nullptr; +  } +  case Intrinsic::eh_sjlj_setup_dispatch: { +    DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_SETUP_DISPATCH, sdl, MVT::Other, +                            getRoot())); +    return nullptr; +  } + +  case Intrinsic::masked_gather: +    visitMaskedGather(I); +    return nullptr; +  case Intrinsic::masked_load: +    visitMaskedLoad(I); +    return nullptr; +  case Intrinsic::masked_scatter: +    visitMaskedScatter(I); +    return nullptr; +  case Intrinsic::masked_store: +    visitMaskedStore(I); +    return nullptr; +  case Intrinsic::masked_expandload: +    visitMaskedLoad(I, true /* IsExpanding */); +    return nullptr; +  case Intrinsic::masked_compressstore: +    visitMaskedStore(I, true /* IsCompressing */); +    return nullptr; +  case Intrinsic::x86_mmx_pslli_w: +  case Intrinsic::x86_mmx_pslli_d: +  case Intrinsic::x86_mmx_pslli_q: +  case Intrinsic::x86_mmx_psrli_w: +  case Intrinsic::x86_mmx_psrli_d: +  case Intrinsic::x86_mmx_psrli_q: +  case Intrinsic::x86_mmx_psrai_w: +  case Intrinsic::x86_mmx_psrai_d: { +    SDValue ShAmt = getValue(I.getArgOperand(1)); +    if (isa<ConstantSDNode>(ShAmt)) { +      visitTargetIntrinsic(I, Intrinsic); +      return nullptr; +    } +    unsigned NewIntrinsic = 0; +    EVT ShAmtVT = MVT::v2i32; +    switch (Intrinsic) { +    case Intrinsic::x86_mmx_pslli_w: +      NewIntrinsic = Intrinsic::x86_mmx_psll_w; +      break; +    case Intrinsic::x86_mmx_pslli_d: +      NewIntrinsic = Intrinsic::x86_mmx_psll_d; +      break; +    case Intrinsic::x86_mmx_pslli_q: +      NewIntrinsic = Intrinsic::x86_mmx_psll_q; +      break; +    case Intrinsic::x86_mmx_psrli_w: +      NewIntrinsic = Intrinsic::x86_mmx_psrl_w; +      break; +    case Intrinsic::x86_mmx_psrli_d: +      NewIntrinsic = Intrinsic::x86_mmx_psrl_d; +      break; +    case Intrinsic::x86_mmx_psrli_q: +      NewIntrinsic = Intrinsic::x86_mmx_psrl_q; +      break; +    case Intrinsic::x86_mmx_psrai_w: +      NewIntrinsic = Intrinsic::x86_mmx_psra_w; +      break; +    case Intrinsic::x86_mmx_psrai_d: +      NewIntrinsic = Intrinsic::x86_mmx_psra_d; +      break; +    default: llvm_unreachable("Impossible intrinsic");  // Can't reach here. +    } + +    // The vector shift intrinsics with scalars uses 32b shift amounts but +    // the sse2/mmx shift instructions reads 64 bits. Set the upper 32 bits +    // to be zero. +    // We must do this early because v2i32 is not a legal type. +    SDValue ShOps[2]; +    ShOps[0] = ShAmt; +    ShOps[1] = DAG.getConstant(0, sdl, MVT::i32); +    ShAmt =  DAG.getBuildVector(ShAmtVT, sdl, ShOps); +    EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType()); +    ShAmt = DAG.getNode(ISD::BITCAST, sdl, DestVT, ShAmt); +    Res = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, sdl, DestVT, +                       DAG.getConstant(NewIntrinsic, sdl, MVT::i32), +                       getValue(I.getArgOperand(0)), ShAmt); +    setValue(&I, Res); +    return nullptr; +  } +  case Intrinsic::powi: +    setValue(&I, ExpandPowI(sdl, getValue(I.getArgOperand(0)), +                            getValue(I.getArgOperand(1)), DAG)); +    return nullptr; +  case Intrinsic::log: +    setValue(&I, expandLog(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); +    return nullptr; +  case Intrinsic::log2: +    setValue(&I, expandLog2(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); +    return nullptr; +  case Intrinsic::log10: +    setValue(&I, expandLog10(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); +    return nullptr; +  case Intrinsic::exp: +    setValue(&I, expandExp(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); +    return nullptr; +  case Intrinsic::exp2: +    setValue(&I, expandExp2(sdl, getValue(I.getArgOperand(0)), DAG, TLI)); +    return nullptr; +  case Intrinsic::pow: +    setValue(&I, expandPow(sdl, getValue(I.getArgOperand(0)), +                           getValue(I.getArgOperand(1)), DAG, TLI)); +    return nullptr; +  case Intrinsic::sqrt: +  case Intrinsic::fabs: +  case Intrinsic::sin: +  case Intrinsic::cos: +  case Intrinsic::floor: +  case Intrinsic::ceil: +  case Intrinsic::trunc: +  case Intrinsic::rint: +  case Intrinsic::nearbyint: +  case Intrinsic::round: +  case Intrinsic::canonicalize: { +    unsigned Opcode; +    switch (Intrinsic) { +    default: llvm_unreachable("Impossible intrinsic");  // Can't reach here. +    case Intrinsic::sqrt:      Opcode = ISD::FSQRT;      break; +    case Intrinsic::fabs:      Opcode = ISD::FABS;       break; +    case Intrinsic::sin:       Opcode = ISD::FSIN;       break; +    case Intrinsic::cos:       Opcode = ISD::FCOS;       break; +    case Intrinsic::floor:     Opcode = ISD::FFLOOR;     break; +    case Intrinsic::ceil:      Opcode = ISD::FCEIL;      break; +    case Intrinsic::trunc:     Opcode = ISD::FTRUNC;     break; +    case Intrinsic::rint:      Opcode = ISD::FRINT;      break; +    case Intrinsic::nearbyint: Opcode = ISD::FNEARBYINT; break; +    case Intrinsic::round:     Opcode = ISD::FROUND;     break; +    case Intrinsic::canonicalize: Opcode = ISD::FCANONICALIZE; break; +    } + +    setValue(&I, DAG.getNode(Opcode, sdl, +                             getValue(I.getArgOperand(0)).getValueType(), +                             getValue(I.getArgOperand(0)))); +    return nullptr; +  } +  case Intrinsic::minnum: { +    auto VT = getValue(I.getArgOperand(0)).getValueType(); +    unsigned Opc = +        I.hasNoNaNs() && TLI.isOperationLegalOrCustom(ISD::FMINNAN, VT) +            ? ISD::FMINNAN +            : ISD::FMINNUM; +    setValue(&I, DAG.getNode(Opc, sdl, VT, +                             getValue(I.getArgOperand(0)), +                             getValue(I.getArgOperand(1)))); +    return nullptr; +  } +  case Intrinsic::maxnum: { +    auto VT = getValue(I.getArgOperand(0)).getValueType(); +    unsigned Opc = +        I.hasNoNaNs() && TLI.isOperationLegalOrCustom(ISD::FMAXNAN, VT) +            ? ISD::FMAXNAN +            : ISD::FMAXNUM; +    setValue(&I, DAG.getNode(Opc, sdl, VT, +                             getValue(I.getArgOperand(0)), +                             getValue(I.getArgOperand(1)))); +    return nullptr; +  } +  case Intrinsic::copysign: +    setValue(&I, DAG.getNode(ISD::FCOPYSIGN, sdl, +                             getValue(I.getArgOperand(0)).getValueType(), +                             getValue(I.getArgOperand(0)), +                             getValue(I.getArgOperand(1)))); +    return nullptr; +  case Intrinsic::fma: +    setValue(&I, DAG.getNode(ISD::FMA, sdl, +                             getValue(I.getArgOperand(0)).getValueType(), +                             getValue(I.getArgOperand(0)), +                             getValue(I.getArgOperand(1)), +                             getValue(I.getArgOperand(2)))); +    return nullptr; +  case Intrinsic::experimental_constrained_fadd: +  case Intrinsic::experimental_constrained_fsub: +  case Intrinsic::experimental_constrained_fmul: +  case Intrinsic::experimental_constrained_fdiv: +  case Intrinsic::experimental_constrained_frem: +  case Intrinsic::experimental_constrained_sqrt: +  case Intrinsic::experimental_constrained_pow: +  case Intrinsic::experimental_constrained_powi: +  case Intrinsic::experimental_constrained_sin: +  case Intrinsic::experimental_constrained_cos: +  case Intrinsic::experimental_constrained_exp: +  case Intrinsic::experimental_constrained_exp2: +  case Intrinsic::experimental_constrained_log: +  case Intrinsic::experimental_constrained_log10: +  case Intrinsic::experimental_constrained_log2: +  case Intrinsic::experimental_constrained_rint: +  case Intrinsic::experimental_constrained_nearbyint: +    visitConstrainedFPIntrinsic(cast<ConstrainedFPIntrinsic>(I)); +    return nullptr; +  case Intrinsic::fmuladd: { +    EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); +    if (TM.Options.AllowFPOpFusion != FPOpFusion::Strict && +        TLI.isFMAFasterThanFMulAndFAdd(VT)) { +      setValue(&I, DAG.getNode(ISD::FMA, sdl, +                               getValue(I.getArgOperand(0)).getValueType(), +                               getValue(I.getArgOperand(0)), +                               getValue(I.getArgOperand(1)), +                               getValue(I.getArgOperand(2)))); +    } else { +      // TODO: Intrinsic calls should have fast-math-flags. +      SDValue Mul = DAG.getNode(ISD::FMUL, sdl, +                                getValue(I.getArgOperand(0)).getValueType(), +                                getValue(I.getArgOperand(0)), +                                getValue(I.getArgOperand(1))); +      SDValue Add = DAG.getNode(ISD::FADD, sdl, +                                getValue(I.getArgOperand(0)).getValueType(), +                                Mul, +                                getValue(I.getArgOperand(2))); +      setValue(&I, Add); +    } +    return nullptr; +  } +  case Intrinsic::convert_to_fp16: +    setValue(&I, DAG.getNode(ISD::BITCAST, sdl, MVT::i16, +                             DAG.getNode(ISD::FP_ROUND, sdl, MVT::f16, +                                         getValue(I.getArgOperand(0)), +                                         DAG.getTargetConstant(0, sdl, +                                                               MVT::i32)))); +    return nullptr; +  case Intrinsic::convert_from_fp16: +    setValue(&I, DAG.getNode(ISD::FP_EXTEND, sdl, +                             TLI.getValueType(DAG.getDataLayout(), I.getType()), +                             DAG.getNode(ISD::BITCAST, sdl, MVT::f16, +                                         getValue(I.getArgOperand(0))))); +    return nullptr; +  case Intrinsic::pcmarker: { +    SDValue Tmp = getValue(I.getArgOperand(0)); +    DAG.setRoot(DAG.getNode(ISD::PCMARKER, sdl, MVT::Other, getRoot(), Tmp)); +    return nullptr; +  } +  case Intrinsic::readcyclecounter: { +    SDValue Op = getRoot(); +    Res = DAG.getNode(ISD::READCYCLECOUNTER, sdl, +                      DAG.getVTList(MVT::i64, MVT::Other), Op); +    setValue(&I, Res); +    DAG.setRoot(Res.getValue(1)); +    return nullptr; +  } +  case Intrinsic::bitreverse: +    setValue(&I, DAG.getNode(ISD::BITREVERSE, sdl, +                             getValue(I.getArgOperand(0)).getValueType(), +                             getValue(I.getArgOperand(0)))); +    return nullptr; +  case Intrinsic::bswap: +    setValue(&I, DAG.getNode(ISD::BSWAP, sdl, +                             getValue(I.getArgOperand(0)).getValueType(), +                             getValue(I.getArgOperand(0)))); +    return nullptr; +  case Intrinsic::cttz: { +    SDValue Arg = getValue(I.getArgOperand(0)); +    ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1)); +    EVT Ty = Arg.getValueType(); +    setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTTZ : ISD::CTTZ_ZERO_UNDEF, +                             sdl, Ty, Arg)); +    return nullptr; +  } +  case Intrinsic::ctlz: { +    SDValue Arg = getValue(I.getArgOperand(0)); +    ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1)); +    EVT Ty = Arg.getValueType(); +    setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTLZ : ISD::CTLZ_ZERO_UNDEF, +                             sdl, Ty, Arg)); +    return nullptr; +  } +  case Intrinsic::ctpop: { +    SDValue Arg = getValue(I.getArgOperand(0)); +    EVT Ty = Arg.getValueType(); +    setValue(&I, DAG.getNode(ISD::CTPOP, sdl, Ty, Arg)); +    return nullptr; +  } +  case Intrinsic::stacksave: { +    SDValue Op = getRoot(); +    Res = DAG.getNode( +        ISD::STACKSAVE, sdl, +        DAG.getVTList(TLI.getPointerTy(DAG.getDataLayout()), MVT::Other), Op); +    setValue(&I, Res); +    DAG.setRoot(Res.getValue(1)); +    return nullptr; +  } +  case Intrinsic::stackrestore: { +    Res = getValue(I.getArgOperand(0)); +    DAG.setRoot(DAG.getNode(ISD::STACKRESTORE, sdl, MVT::Other, getRoot(), Res)); +    return nullptr; +  } +  case Intrinsic::get_dynamic_area_offset: { +    SDValue Op = getRoot(); +    EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); +    EVT ResTy = TLI.getValueType(DAG.getDataLayout(), I.getType()); +    // Result type for @llvm.get.dynamic.area.offset should match PtrTy for +    // target. +    if (PtrTy != ResTy) +      report_fatal_error("Wrong result type for @llvm.get.dynamic.area.offset" +                         " intrinsic!"); +    Res = DAG.getNode(ISD::GET_DYNAMIC_AREA_OFFSET, sdl, DAG.getVTList(ResTy), +                      Op); +    DAG.setRoot(Op); +    setValue(&I, Res); +    return nullptr; +  } +  case Intrinsic::stackguard: { +    EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); +    MachineFunction &MF = DAG.getMachineFunction(); +    const Module &M = *MF.getFunction()->getParent(); +    SDValue Chain = getRoot(); +    if (TLI.useLoadStackGuardNode()) { +      Res = getLoadStackGuard(DAG, sdl, Chain); +    } else { +      const Value *Global = TLI.getSDagStackGuard(M); +      unsigned Align = DL->getPrefTypeAlignment(Global->getType()); +      Res = DAG.getLoad(PtrTy, sdl, Chain, getValue(Global), +                        MachinePointerInfo(Global, 0), Align, +                        MachineMemOperand::MOVolatile); +    } +    DAG.setRoot(Chain); +    setValue(&I, Res); +    return nullptr; +  } +  case Intrinsic::stackprotector: { +    // Emit code into the DAG to store the stack guard onto the stack. +    MachineFunction &MF = DAG.getMachineFunction(); +    MachineFrameInfo &MFI = MF.getFrameInfo(); +    EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout()); +    SDValue Src, Chain = getRoot(); + +    if (TLI.useLoadStackGuardNode()) +      Src = getLoadStackGuard(DAG, sdl, Chain); +    else +      Src = getValue(I.getArgOperand(0));   // The guard's value. + +    AllocaInst *Slot = cast<AllocaInst>(I.getArgOperand(1)); + +    int FI = FuncInfo.StaticAllocaMap[Slot]; +    MFI.setStackProtectorIndex(FI); + +    SDValue FIN = DAG.getFrameIndex(FI, PtrTy); + +    // Store the stack protector onto the stack. +    Res = DAG.getStore(Chain, sdl, Src, FIN, MachinePointerInfo::getFixedStack( +                                                 DAG.getMachineFunction(), FI), +                       /* Alignment = */ 0, MachineMemOperand::MOVolatile); +    setValue(&I, Res); +    DAG.setRoot(Res); +    return nullptr; +  } +  case Intrinsic::objectsize: { +    // If we don't know by now, we're never going to know. +    ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(1)); + +    assert(CI && "Non-constant type in __builtin_object_size?"); + +    SDValue Arg = getValue(I.getCalledValue()); +    EVT Ty = Arg.getValueType(); + +    if (CI->isZero()) +      Res = DAG.getConstant(-1ULL, sdl, Ty); +    else +      Res = DAG.getConstant(0, sdl, Ty); + +    setValue(&I, Res); +    return nullptr; +  } +  case Intrinsic::annotation: +  case Intrinsic::ptr_annotation: +  case Intrinsic::invariant_group_barrier: +    // Drop the intrinsic, but forward the value +    setValue(&I, getValue(I.getOperand(0))); +    return nullptr; +  case Intrinsic::assume: +  case Intrinsic::var_annotation: +    // Discard annotate attributes and assumptions +    return nullptr; + +  case Intrinsic::init_trampoline: { +    const Function *F = cast<Function>(I.getArgOperand(1)->stripPointerCasts()); + +    SDValue Ops[6]; +    Ops[0] = getRoot(); +    Ops[1] = getValue(I.getArgOperand(0)); +    Ops[2] = getValue(I.getArgOperand(1)); +    Ops[3] = getValue(I.getArgOperand(2)); +    Ops[4] = DAG.getSrcValue(I.getArgOperand(0)); +    Ops[5] = DAG.getSrcValue(F); + +    Res = DAG.getNode(ISD::INIT_TRAMPOLINE, sdl, MVT::Other, Ops); + +    DAG.setRoot(Res); +    return nullptr; +  } +  case Intrinsic::adjust_trampoline: { +    setValue(&I, DAG.getNode(ISD::ADJUST_TRAMPOLINE, sdl, +                             TLI.getPointerTy(DAG.getDataLayout()), +                             getValue(I.getArgOperand(0)))); +    return nullptr; +  } +  case Intrinsic::gcroot: { +    MachineFunction &MF = DAG.getMachineFunction(); +    const Function *F = MF.getFunction(); +    (void)F; +    assert(F->hasGC() && +           "only valid in functions with gc specified, enforced by Verifier"); +    assert(GFI && "implied by previous"); +    const Value *Alloca = I.getArgOperand(0)->stripPointerCasts(); +    const Constant *TypeMap = cast<Constant>(I.getArgOperand(1)); + +    FrameIndexSDNode *FI = cast<FrameIndexSDNode>(getValue(Alloca).getNode()); +    GFI->addStackRoot(FI->getIndex(), TypeMap); +    return nullptr; +  } +  case Intrinsic::gcread: +  case Intrinsic::gcwrite: +    llvm_unreachable("GC failed to lower gcread/gcwrite intrinsics!"); +  case Intrinsic::flt_rounds: +    setValue(&I, DAG.getNode(ISD::FLT_ROUNDS_, sdl, MVT::i32)); +    return nullptr; + +  case Intrinsic::expect: { +    // Just replace __builtin_expect(exp, c) with EXP. +    setValue(&I, getValue(I.getArgOperand(0))); +    return nullptr; +  } + +  case Intrinsic::debugtrap: +  case Intrinsic::trap: { +    StringRef TrapFuncName = +        I.getAttributes() +            .getAttribute(AttributeList::FunctionIndex, "trap-func-name") +            .getValueAsString(); +    if (TrapFuncName.empty()) { +      ISD::NodeType Op = (Intrinsic == Intrinsic::trap) ? +        ISD::TRAP : ISD::DEBUGTRAP; +      DAG.setRoot(DAG.getNode(Op, sdl,MVT::Other, getRoot())); +      return nullptr; +    } +    TargetLowering::ArgListTy Args; + +    TargetLowering::CallLoweringInfo CLI(DAG); +    CLI.setDebugLoc(sdl).setChain(getRoot()).setLibCallee( +        CallingConv::C, I.getType(), +        DAG.getExternalSymbol(TrapFuncName.data(), +                              TLI.getPointerTy(DAG.getDataLayout())), +        std::move(Args)); + +    std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI); +    DAG.setRoot(Result.second); +    return nullptr; +  } + +  case Intrinsic::uadd_with_overflow: +  case Intrinsic::sadd_with_overflow: +  case Intrinsic::usub_with_overflow: +  case Intrinsic::ssub_with_overflow: +  case Intrinsic::umul_with_overflow: +  case Intrinsic::smul_with_overflow: { +    ISD::NodeType Op; +    switch (Intrinsic) { +    default: llvm_unreachable("Impossible intrinsic");  // Can't reach here. +    case Intrinsic::uadd_with_overflow: Op = ISD::UADDO; break; +    case Intrinsic::sadd_with_overflow: Op = ISD::SADDO; break; +    case Intrinsic::usub_with_overflow: Op = ISD::USUBO; break; +    case Intrinsic::ssub_with_overflow: Op = ISD::SSUBO; break; +    case Intrinsic::umul_with_overflow: Op = ISD::UMULO; break; +    case Intrinsic::smul_with_overflow: Op = ISD::SMULO; break; +    } +    SDValue Op1 = getValue(I.getArgOperand(0)); +    SDValue Op2 = getValue(I.getArgOperand(1)); + +    SDVTList VTs = DAG.getVTList(Op1.getValueType(), MVT::i1); +    setValue(&I, DAG.getNode(Op, sdl, VTs, Op1, Op2)); +    return nullptr; +  } +  case Intrinsic::prefetch: { +    SDValue Ops[5]; +    unsigned rw = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue(); +    Ops[0] = getRoot(); +    Ops[1] = getValue(I.getArgOperand(0)); +    Ops[2] = getValue(I.getArgOperand(1)); +    Ops[3] = getValue(I.getArgOperand(2)); +    Ops[4] = getValue(I.getArgOperand(3)); +    DAG.setRoot(DAG.getMemIntrinsicNode(ISD::PREFETCH, sdl, +                                        DAG.getVTList(MVT::Other), Ops, +                                        EVT::getIntegerVT(*Context, 8), +                                        MachinePointerInfo(I.getArgOperand(0)), +                                        0, /* align */ +                                        false, /* volatile */ +                                        rw==0, /* read */ +                                        rw==1)); /* write */ +    return nullptr; +  } +  case Intrinsic::lifetime_start: +  case Intrinsic::lifetime_end: { +    bool IsStart = (Intrinsic == Intrinsic::lifetime_start); +    // Stack coloring is not enabled in O0, discard region information. +    if (TM.getOptLevel() == CodeGenOpt::None) +      return nullptr; + +    SmallVector<Value *, 4> Allocas; +    GetUnderlyingObjects(I.getArgOperand(1), Allocas, *DL); + +    for (SmallVectorImpl<Value*>::iterator Object = Allocas.begin(), +           E = Allocas.end(); Object != E; ++Object) { +      AllocaInst *LifetimeObject = dyn_cast_or_null<AllocaInst>(*Object); + +      // Could not find an Alloca. +      if (!LifetimeObject) +        continue; + +      // First check that the Alloca is static, otherwise it won't have a +      // valid frame index. +      auto SI = FuncInfo.StaticAllocaMap.find(LifetimeObject); +      if (SI == FuncInfo.StaticAllocaMap.end()) +        return nullptr; + +      int FI = SI->second; + +      SDValue Ops[2]; +      Ops[0] = getRoot(); +      Ops[1] = +          DAG.getFrameIndex(FI, TLI.getFrameIndexTy(DAG.getDataLayout()), true); +      unsigned Opcode = (IsStart ? ISD::LIFETIME_START : ISD::LIFETIME_END); + +      Res = DAG.getNode(Opcode, sdl, MVT::Other, Ops); +      DAG.setRoot(Res); +    } +    return nullptr; +  } +  case Intrinsic::invariant_start: +    // Discard region information. +    setValue(&I, DAG.getUNDEF(TLI.getPointerTy(DAG.getDataLayout()))); +    return nullptr; +  case Intrinsic::invariant_end: +    // Discard region information. +    return nullptr; +  case Intrinsic::clear_cache: +    return TLI.getClearCacheBuiltinName(); +  case Intrinsic::donothing: +    // ignore +    return nullptr; +  case Intrinsic::experimental_stackmap: { +    visitStackmap(I); +    return nullptr; +  } +  case Intrinsic::experimental_patchpoint_void: +  case Intrinsic::experimental_patchpoint_i64: { +    visitPatchpoint(&I); +    return nullptr; +  } +  case Intrinsic::experimental_gc_statepoint: { +    LowerStatepoint(ImmutableStatepoint(&I)); +    return nullptr; +  } +  case Intrinsic::experimental_gc_result: { +    visitGCResult(cast<GCResultInst>(I)); +    return nullptr; +  } +  case Intrinsic::experimental_gc_relocate: { +    visitGCRelocate(cast<GCRelocateInst>(I)); +    return nullptr; +  } +  case Intrinsic::instrprof_increment: +    llvm_unreachable("instrprof failed to lower an increment"); +  case Intrinsic::instrprof_value_profile: +    llvm_unreachable("instrprof failed to lower a value profiling call"); +  case Intrinsic::localescape: { +    MachineFunction &MF = DAG.getMachineFunction(); +    const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo(); + +    // Directly emit some LOCAL_ESCAPE machine instrs. Label assignment emission +    // is the same on all targets. +    for (unsigned Idx = 0, E = I.getNumArgOperands(); Idx < E; ++Idx) { +      Value *Arg = I.getArgOperand(Idx)->stripPointerCasts(); +      if (isa<ConstantPointerNull>(Arg)) +        continue; // Skip null pointers. They represent a hole in index space. +      AllocaInst *Slot = cast<AllocaInst>(Arg); +      assert(FuncInfo.StaticAllocaMap.count(Slot) && +             "can only escape static allocas"); +      int FI = FuncInfo.StaticAllocaMap[Slot]; +      MCSymbol *FrameAllocSym = +          MF.getMMI().getContext().getOrCreateFrameAllocSymbol( +              GlobalValue::dropLLVMManglingEscape(MF.getName()), Idx); +      BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, dl, +              TII->get(TargetOpcode::LOCAL_ESCAPE)) +          .addSym(FrameAllocSym) +          .addFrameIndex(FI); +    } + +    return nullptr; +  } + +  case Intrinsic::localrecover: { +    // i8* @llvm.localrecover(i8* %fn, i8* %fp, i32 %idx) +    MachineFunction &MF = DAG.getMachineFunction(); +    MVT PtrVT = TLI.getPointerTy(DAG.getDataLayout(), 0); + +    // Get the symbol that defines the frame offset. +    auto *Fn = cast<Function>(I.getArgOperand(0)->stripPointerCasts()); +    auto *Idx = cast<ConstantInt>(I.getArgOperand(2)); +    unsigned IdxVal = unsigned(Idx->getLimitedValue(INT_MAX)); +    MCSymbol *FrameAllocSym = +        MF.getMMI().getContext().getOrCreateFrameAllocSymbol( +            GlobalValue::dropLLVMManglingEscape(Fn->getName()), IdxVal); + +    // Create a MCSymbol for the label to avoid any target lowering +    // that would make this PC relative. +    SDValue OffsetSym = DAG.getMCSymbol(FrameAllocSym, PtrVT); +    SDValue OffsetVal = +        DAG.getNode(ISD::LOCAL_RECOVER, sdl, PtrVT, OffsetSym); + +    // Add the offset to the FP. +    Value *FP = I.getArgOperand(1); +    SDValue FPVal = getValue(FP); +    SDValue Add = DAG.getNode(ISD::ADD, sdl, PtrVT, FPVal, OffsetVal); +    setValue(&I, Add); + +    return nullptr; +  } + +  case Intrinsic::eh_exceptionpointer: +  case Intrinsic::eh_exceptioncode: { +    // Get the exception pointer vreg, copy from it, and resize it to fit. +    const auto *CPI = cast<CatchPadInst>(I.getArgOperand(0)); +    MVT PtrVT = TLI.getPointerTy(DAG.getDataLayout()); +    const TargetRegisterClass *PtrRC = TLI.getRegClassFor(PtrVT); +    unsigned VReg = FuncInfo.getCatchPadExceptionPointerVReg(CPI, PtrRC); +    SDValue N = +        DAG.getCopyFromReg(DAG.getEntryNode(), getCurSDLoc(), VReg, PtrVT); +    if (Intrinsic == Intrinsic::eh_exceptioncode) +      N = DAG.getZExtOrTrunc(N, getCurSDLoc(), MVT::i32); +    setValue(&I, N); +    return nullptr; +  } +  case Intrinsic::xray_customevent: { +    // Here we want to make sure that the intrinsic behaves as if it has a +    // specific calling convention, and only for x86_64. +    // FIXME: Support other platforms later. +    const auto &Triple = DAG.getTarget().getTargetTriple(); +    if (Triple.getArch() != Triple::x86_64 || !Triple.isOSLinux()) +      return nullptr; + +    SDLoc DL = getCurSDLoc(); +    SmallVector<SDValue, 8> Ops; + +    // We want to say that we always want the arguments in registers. +    SDValue LogEntryVal = getValue(I.getArgOperand(0)); +    SDValue StrSizeVal = getValue(I.getArgOperand(1)); +    SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); +    SDValue Chain = getRoot(); +    Ops.push_back(LogEntryVal); +    Ops.push_back(StrSizeVal); +    Ops.push_back(Chain); + +    // We need to enforce the calling convention for the callsite, so that +    // argument ordering is enforced correctly, and that register allocation can +    // see that some registers may be assumed clobbered and have to preserve +    // them across calls to the intrinsic. +    MachineSDNode *MN = DAG.getMachineNode(TargetOpcode::PATCHABLE_EVENT_CALL, +                                           DL, NodeTys, Ops); +    SDValue patchableNode = SDValue(MN, 0); +    DAG.setRoot(patchableNode); +    setValue(&I, patchableNode); +    return nullptr; +  } +  case Intrinsic::experimental_deoptimize: +    LowerDeoptimizeCall(&I); +    return nullptr; + +  case Intrinsic::experimental_vector_reduce_fadd: +  case Intrinsic::experimental_vector_reduce_fmul: +  case Intrinsic::experimental_vector_reduce_add: +  case Intrinsic::experimental_vector_reduce_mul: +  case Intrinsic::experimental_vector_reduce_and: +  case Intrinsic::experimental_vector_reduce_or: +  case Intrinsic::experimental_vector_reduce_xor: +  case Intrinsic::experimental_vector_reduce_smax: +  case Intrinsic::experimental_vector_reduce_smin: +  case Intrinsic::experimental_vector_reduce_umax: +  case Intrinsic::experimental_vector_reduce_umin: +  case Intrinsic::experimental_vector_reduce_fmax: +  case Intrinsic::experimental_vector_reduce_fmin: { +    visitVectorReduce(I, Intrinsic); +    return nullptr; +  } + +  } +} + +void SelectionDAGBuilder::visitConstrainedFPIntrinsic( +    const ConstrainedFPIntrinsic &FPI) { +  SDLoc sdl = getCurSDLoc(); +  unsigned Opcode; +  switch (FPI.getIntrinsicID()) { +  default: llvm_unreachable("Impossible intrinsic");  // Can't reach here. +  case Intrinsic::experimental_constrained_fadd: +    Opcode = ISD::STRICT_FADD; +    break; +  case Intrinsic::experimental_constrained_fsub: +    Opcode = ISD::STRICT_FSUB; +    break; +  case Intrinsic::experimental_constrained_fmul: +    Opcode = ISD::STRICT_FMUL; +    break; +  case Intrinsic::experimental_constrained_fdiv: +    Opcode = ISD::STRICT_FDIV; +    break; +  case Intrinsic::experimental_constrained_frem: +    Opcode = ISD::STRICT_FREM; +    break; +  case Intrinsic::experimental_constrained_sqrt: +    Opcode = ISD::STRICT_FSQRT; +    break; +  case Intrinsic::experimental_constrained_pow: +    Opcode = ISD::STRICT_FPOW; +    break; +  case Intrinsic::experimental_constrained_powi: +    Opcode = ISD::STRICT_FPOWI; +    break; +  case Intrinsic::experimental_constrained_sin: +    Opcode = ISD::STRICT_FSIN; +    break; +  case Intrinsic::experimental_constrained_cos: +    Opcode = ISD::STRICT_FCOS; +    break; +  case Intrinsic::experimental_constrained_exp: +    Opcode = ISD::STRICT_FEXP; +    break; +  case Intrinsic::experimental_constrained_exp2: +    Opcode = ISD::STRICT_FEXP2; +    break; +  case Intrinsic::experimental_constrained_log: +    Opcode = ISD::STRICT_FLOG; +    break; +  case Intrinsic::experimental_constrained_log10: +    Opcode = ISD::STRICT_FLOG10; +    break; +  case Intrinsic::experimental_constrained_log2: +    Opcode = ISD::STRICT_FLOG2; +    break; +  case Intrinsic::experimental_constrained_rint: +    Opcode = ISD::STRICT_FRINT; +    break; +  case Intrinsic::experimental_constrained_nearbyint: +    Opcode = ISD::STRICT_FNEARBYINT; +    break; +  } +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue Chain = getRoot(); +  SmallVector<EVT, 4> ValueVTs; +  ComputeValueVTs(TLI, DAG.getDataLayout(), FPI.getType(), ValueVTs); +  ValueVTs.push_back(MVT::Other); // Out chain + +  SDVTList VTs = DAG.getVTList(ValueVTs); +  SDValue Result; +  if (FPI.isUnaryOp()) +    Result = DAG.getNode(Opcode, sdl, VTs,  +                         { Chain, getValue(FPI.getArgOperand(0)) }); +  else +    Result = DAG.getNode(Opcode, sdl, VTs,  +                         { Chain, getValue(FPI.getArgOperand(0)), +                           getValue(FPI.getArgOperand(1))  }); + +  assert(Result.getNode()->getNumValues() == 2); +  SDValue OutChain = Result.getValue(1); +  DAG.setRoot(OutChain); +  SDValue FPResult = Result.getValue(0); +  setValue(&FPI, FPResult); +} + +std::pair<SDValue, SDValue> +SelectionDAGBuilder::lowerInvokable(TargetLowering::CallLoweringInfo &CLI, +                                    const BasicBlock *EHPadBB) { +  MachineFunction &MF = DAG.getMachineFunction(); +  MachineModuleInfo &MMI = MF.getMMI(); +  MCSymbol *BeginLabel = nullptr; + +  if (EHPadBB) { +    // Insert a label before the invoke call to mark the try range.  This can be +    // used to detect deletion of the invoke via the MachineModuleInfo. +    BeginLabel = MMI.getContext().createTempSymbol(); + +    // For SjLj, keep track of which landing pads go with which invokes +    // so as to maintain the ordering of pads in the LSDA. +    unsigned CallSiteIndex = MMI.getCurrentCallSite(); +    if (CallSiteIndex) { +      MF.setCallSiteBeginLabel(BeginLabel, CallSiteIndex); +      LPadToCallSiteMap[FuncInfo.MBBMap[EHPadBB]].push_back(CallSiteIndex); + +      // Now that the call site is handled, stop tracking it. +      MMI.setCurrentCallSite(0); +    } + +    // Both PendingLoads and PendingExports must be flushed here; +    // this call might not return. +    (void)getRoot(); +    DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getControlRoot(), BeginLabel)); + +    CLI.setChain(getRoot()); +  } +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI); + +  assert((CLI.IsTailCall || Result.second.getNode()) && +         "Non-null chain expected with non-tail call!"); +  assert((Result.second.getNode() || !Result.first.getNode()) && +         "Null value expected with tail call!"); + +  if (!Result.second.getNode()) { +    // As a special case, a null chain means that a tail call has been emitted +    // and the DAG root is already updated. +    HasTailCall = true; + +    // Since there's no actual continuation from this block, nothing can be +    // relying on us setting vregs for them. +    PendingExports.clear(); +  } else { +    DAG.setRoot(Result.second); +  } + +  if (EHPadBB) { +    // Insert a label at the end of the invoke call to mark the try range.  This +    // can be used to detect deletion of the invoke via the MachineModuleInfo. +    MCSymbol *EndLabel = MMI.getContext().createTempSymbol(); +    DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getRoot(), EndLabel)); + +    // Inform MachineModuleInfo of range. +    if (MF.hasEHFunclets()) { +      assert(CLI.CS); +      WinEHFuncInfo *EHInfo = DAG.getMachineFunction().getWinEHFuncInfo(); +      EHInfo->addIPToStateRange(cast<InvokeInst>(CLI.CS->getInstruction()), +                                BeginLabel, EndLabel); +    } else { +      MF.addInvoke(FuncInfo.MBBMap[EHPadBB], BeginLabel, EndLabel); +    } +  } + +  return Result; +} + +void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee, +                                      bool isTailCall, +                                      const BasicBlock *EHPadBB) { +  auto &DL = DAG.getDataLayout(); +  FunctionType *FTy = CS.getFunctionType(); +  Type *RetTy = CS.getType(); + +  TargetLowering::ArgListTy Args; +  Args.reserve(CS.arg_size()); + +  const Value *SwiftErrorVal = nullptr; +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); + +  // We can't tail call inside a function with a swifterror argument. Lowering +  // does not support this yet. It would have to move into the swifterror +  // register before the call. +  auto *Caller = CS.getInstruction()->getParent()->getParent(); +  if (TLI.supportSwiftError() && +      Caller->getAttributes().hasAttrSomewhere(Attribute::SwiftError)) +    isTailCall = false; + +  for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end(); +       i != e; ++i) { +    TargetLowering::ArgListEntry Entry; +    const Value *V = *i; + +    // Skip empty types +    if (V->getType()->isEmptyTy()) +      continue; + +    SDValue ArgNode = getValue(V); +    Entry.Node = ArgNode; Entry.Ty = V->getType(); + +    Entry.setAttributes(&CS, i - CS.arg_begin()); + +    // Use swifterror virtual register as input to the call. +    if (Entry.IsSwiftError && TLI.supportSwiftError()) { +      SwiftErrorVal = V; +      // We find the virtual register for the actual swifterror argument. +      // Instead of using the Value, we use the virtual register instead. +      Entry.Node = DAG.getRegister(FuncInfo +                                       .getOrCreateSwiftErrorVRegUseAt( +                                           CS.getInstruction(), FuncInfo.MBB, V) +                                       .first, +                                   EVT(TLI.getPointerTy(DL))); +    } + +    Args.push_back(Entry); + +    // If we have an explicit sret argument that is an Instruction, (i.e., it +    // might point to function-local memory), we can't meaningfully tail-call. +    if (Entry.IsSRet && isa<Instruction>(V)) +      isTailCall = false; +  } + +  // Check if target-independent constraints permit a tail call here. +  // Target-dependent constraints are checked within TLI->LowerCallTo. +  if (isTailCall && !isInTailCallPosition(CS, DAG.getTarget())) +    isTailCall = false; + +  // Disable tail calls if there is an swifterror argument. Targets have not +  // been updated to support tail calls. +  if (TLI.supportSwiftError() && SwiftErrorVal) +    isTailCall = false; + +  TargetLowering::CallLoweringInfo CLI(DAG); +  CLI.setDebugLoc(getCurSDLoc()) +      .setChain(getRoot()) +      .setCallee(RetTy, FTy, Callee, std::move(Args), CS) +      .setTailCall(isTailCall) +      .setConvergent(CS.isConvergent()); +  std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB); + +  if (Result.first.getNode()) { +    const Instruction *Inst = CS.getInstruction(); +    Result.first = lowerRangeToAssertZExt(DAG, *Inst, Result.first); +    setValue(Inst, Result.first); +  } + +  // The last element of CLI.InVals has the SDValue for swifterror return. +  // Here we copy it to a virtual register and update SwiftErrorMap for +  // book-keeping. +  if (SwiftErrorVal && TLI.supportSwiftError()) { +    // Get the last element of InVals. +    SDValue Src = CLI.InVals.back(); +    unsigned VReg; bool CreatedVReg; +    std::tie(VReg, CreatedVReg) = +        FuncInfo.getOrCreateSwiftErrorVRegDefAt(CS.getInstruction()); +    SDValue CopyNode = CLI.DAG.getCopyToReg(Result.second, CLI.DL, VReg, Src); +    // We update the virtual register for the actual swifterror argument. +    if (CreatedVReg) +      FuncInfo.setCurrentSwiftErrorVReg(FuncInfo.MBB, SwiftErrorVal, VReg); +    DAG.setRoot(CopyNode); +  } +} + +static SDValue getMemCmpLoad(const Value *PtrVal, MVT LoadVT, +                             SelectionDAGBuilder &Builder) { + +  // Check to see if this load can be trivially constant folded, e.g. if the +  // input is from a string literal. +  if (const Constant *LoadInput = dyn_cast<Constant>(PtrVal)) { +    // Cast pointer to the type we really want to load. +    Type *LoadTy = +        Type::getIntNTy(PtrVal->getContext(), LoadVT.getScalarSizeInBits()); +    if (LoadVT.isVector()) +      LoadTy = VectorType::get(LoadTy, LoadVT.getVectorNumElements()); + +    LoadInput = ConstantExpr::getBitCast(const_cast<Constant *>(LoadInput), +                                         PointerType::getUnqual(LoadTy)); + +    if (const Constant *LoadCst = ConstantFoldLoadFromConstPtr( +            const_cast<Constant *>(LoadInput), LoadTy, *Builder.DL)) +      return Builder.getValue(LoadCst); +  } + +  // Otherwise, we have to emit the load.  If the pointer is to unfoldable but +  // still constant memory, the input chain can be the entry node. +  SDValue Root; +  bool ConstantMemory = false; + +  // Do not serialize (non-volatile) loads of constant memory with anything. +  if (Builder.AA && Builder.AA->pointsToConstantMemory(PtrVal)) { +    Root = Builder.DAG.getEntryNode(); +    ConstantMemory = true; +  } else { +    // Do not serialize non-volatile loads against each other. +    Root = Builder.DAG.getRoot(); +  } + +  SDValue Ptr = Builder.getValue(PtrVal); +  SDValue LoadVal = Builder.DAG.getLoad(LoadVT, Builder.getCurSDLoc(), Root, +                                        Ptr, MachinePointerInfo(PtrVal), +                                        /* Alignment = */ 1); + +  if (!ConstantMemory) +    Builder.PendingLoads.push_back(LoadVal.getValue(1)); +  return LoadVal; +} + +/// Record the value for an instruction that produces an integer result, +/// converting the type where necessary. +void SelectionDAGBuilder::processIntegerCallValue(const Instruction &I, +                                                  SDValue Value, +                                                  bool IsSigned) { +  EVT VT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                    I.getType(), true); +  if (IsSigned) +    Value = DAG.getSExtOrTrunc(Value, getCurSDLoc(), VT); +  else +    Value = DAG.getZExtOrTrunc(Value, getCurSDLoc(), VT); +  setValue(&I, Value); +} + +/// See if we can lower a memcmp call into an optimized form. If so, return +/// true and lower it. Otherwise return false, and it will be lowered like a +/// normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitMemCmpCall(const CallInst &I) { +  const Value *LHS = I.getArgOperand(0), *RHS = I.getArgOperand(1); +  const Value *Size = I.getArgOperand(2); +  const ConstantInt *CSize = dyn_cast<ConstantInt>(Size); +  if (CSize && CSize->getZExtValue() == 0) { +    EVT CallVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(), +                                                          I.getType(), true); +    setValue(&I, DAG.getConstant(0, getCurSDLoc(), CallVT)); +    return true; +  } + +  const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); +  std::pair<SDValue, SDValue> Res = TSI.EmitTargetCodeForMemcmp( +      DAG, getCurSDLoc(), DAG.getRoot(), getValue(LHS), getValue(RHS), +      getValue(Size), MachinePointerInfo(LHS), MachinePointerInfo(RHS)); +  if (Res.first.getNode()) { +    processIntegerCallValue(I, Res.first, true); +    PendingLoads.push_back(Res.second); +    return true; +  } + +  // memcmp(S1,S2,2) != 0 -> (*(short*)LHS != *(short*)RHS)  != 0 +  // memcmp(S1,S2,4) != 0 -> (*(int*)LHS != *(int*)RHS)  != 0 +  if (!CSize || !isOnlyUsedInZeroEqualityComparison(&I)) +    return false; + +  // If the target has a fast compare for the given size, it will return a +  // preferred load type for that size. Require that the load VT is legal and +  // that the target supports unaligned loads of that type. Otherwise, return +  // INVALID. +  auto hasFastLoadsAndCompare = [&](unsigned NumBits) { +    const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +    MVT LVT = TLI.hasFastEqualityCompare(NumBits); +    if (LVT != MVT::INVALID_SIMPLE_VALUE_TYPE) { +      // TODO: Handle 5 byte compare as 4-byte + 1 byte. +      // TODO: Handle 8 byte compare on x86-32 as two 32-bit loads. +      // TODO: Check alignment of src and dest ptrs. +      unsigned DstAS = LHS->getType()->getPointerAddressSpace(); +      unsigned SrcAS = RHS->getType()->getPointerAddressSpace(); +      if (!TLI.isTypeLegal(LVT) || +          !TLI.allowsMisalignedMemoryAccesses(LVT, SrcAS) || +          !TLI.allowsMisalignedMemoryAccesses(LVT, DstAS)) +        LVT = MVT::INVALID_SIMPLE_VALUE_TYPE; +    } + +    return LVT; +  }; + +  // This turns into unaligned loads. We only do this if the target natively +  // supports the MVT we'll be loading or if it is small enough (<= 4) that +  // we'll only produce a small number of byte loads. +  MVT LoadVT; +  unsigned NumBitsToCompare = CSize->getZExtValue() * 8; +  switch (NumBitsToCompare) { +  default: +    return false; +  case 16: +    LoadVT = MVT::i16; +    break; +  case 32: +    LoadVT = MVT::i32; +    break; +  case 64: +  case 128: +  case 256: +    LoadVT = hasFastLoadsAndCompare(NumBitsToCompare); +    break; +  } + +  if (LoadVT == MVT::INVALID_SIMPLE_VALUE_TYPE) +    return false; + +  SDValue LoadL = getMemCmpLoad(LHS, LoadVT, *this); +  SDValue LoadR = getMemCmpLoad(RHS, LoadVT, *this); + +  // Bitcast to a wide integer type if the loads are vectors. +  if (LoadVT.isVector()) { +    EVT CmpVT = EVT::getIntegerVT(LHS->getContext(), LoadVT.getSizeInBits()); +    LoadL = DAG.getBitcast(CmpVT, LoadL); +    LoadR = DAG.getBitcast(CmpVT, LoadR); +  } + +  SDValue Cmp = DAG.getSetCC(getCurSDLoc(), MVT::i1, LoadL, LoadR, ISD::SETNE); +  processIntegerCallValue(I, Cmp, false); +  return true; +} + +/// See if we can lower a memchr call into an optimized form. If so, return +/// true and lower it. Otherwise return false, and it will be lowered like a +/// normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitMemChrCall(const CallInst &I) { +  const Value *Src = I.getArgOperand(0); +  const Value *Char = I.getArgOperand(1); +  const Value *Length = I.getArgOperand(2); + +  const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); +  std::pair<SDValue, SDValue> Res = +    TSI.EmitTargetCodeForMemchr(DAG, getCurSDLoc(), DAG.getRoot(), +                                getValue(Src), getValue(Char), getValue(Length), +                                MachinePointerInfo(Src)); +  if (Res.first.getNode()) { +    setValue(&I, Res.first); +    PendingLoads.push_back(Res.second); +    return true; +  } + +  return false; +} + +/// See if we can lower a mempcpy call into an optimized form. If so, return +/// true and lower it. Otherwise return false, and it will be lowered like a +/// normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitMemPCpyCall(const CallInst &I) { +  SDValue Dst = getValue(I.getArgOperand(0)); +  SDValue Src = getValue(I.getArgOperand(1)); +  SDValue Size = getValue(I.getArgOperand(2)); + +  unsigned DstAlign = DAG.InferPtrAlignment(Dst); +  unsigned SrcAlign = DAG.InferPtrAlignment(Src); +  unsigned Align = std::min(DstAlign, SrcAlign); +  if (Align == 0) // Alignment of one or both could not be inferred. +    Align = 1; // 0 and 1 both specify no alignment, but 0 is reserved. + +  bool isVol = false; +  SDLoc sdl = getCurSDLoc(); + +  // In the mempcpy context we need to pass in a false value for isTailCall +  // because the return pointer needs to be adjusted by the size of +  // the copied memory. +  SDValue MC = DAG.getMemcpy(getRoot(), sdl, Dst, Src, Size, Align, isVol, +                             false, /*isTailCall=*/false, +                             MachinePointerInfo(I.getArgOperand(0)), +                             MachinePointerInfo(I.getArgOperand(1))); +  assert(MC.getNode() != nullptr && +         "** memcpy should not be lowered as TailCall in mempcpy context **"); +  DAG.setRoot(MC); + +  // Check if Size needs to be truncated or extended. +  Size = DAG.getSExtOrTrunc(Size, sdl, Dst.getValueType()); + +  // Adjust return pointer to point just past the last dst byte. +  SDValue DstPlusSize = DAG.getNode(ISD::ADD, sdl, Dst.getValueType(), +                                    Dst, Size); +  setValue(&I, DstPlusSize); +  return true; +} + +/// See if we can lower a strcpy call into an optimized form.  If so, return +/// true and lower it, otherwise return false and it will be lowered like a +/// normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitStrCpyCall(const CallInst &I, bool isStpcpy) { +  const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1); + +  const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); +  std::pair<SDValue, SDValue> Res = +    TSI.EmitTargetCodeForStrcpy(DAG, getCurSDLoc(), getRoot(), +                                getValue(Arg0), getValue(Arg1), +                                MachinePointerInfo(Arg0), +                                MachinePointerInfo(Arg1), isStpcpy); +  if (Res.first.getNode()) { +    setValue(&I, Res.first); +    DAG.setRoot(Res.second); +    return true; +  } + +  return false; +} + +/// See if we can lower a strcmp call into an optimized form.  If so, return +/// true and lower it, otherwise return false and it will be lowered like a +/// normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitStrCmpCall(const CallInst &I) { +  const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1); + +  const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); +  std::pair<SDValue, SDValue> Res = +    TSI.EmitTargetCodeForStrcmp(DAG, getCurSDLoc(), DAG.getRoot(), +                                getValue(Arg0), getValue(Arg1), +                                MachinePointerInfo(Arg0), +                                MachinePointerInfo(Arg1)); +  if (Res.first.getNode()) { +    processIntegerCallValue(I, Res.first, true); +    PendingLoads.push_back(Res.second); +    return true; +  } + +  return false; +} + +/// See if we can lower a strlen call into an optimized form.  If so, return +/// true and lower it, otherwise return false and it will be lowered like a +/// normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitStrLenCall(const CallInst &I) { +  const Value *Arg0 = I.getArgOperand(0); + +  const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); +  std::pair<SDValue, SDValue> Res = +    TSI.EmitTargetCodeForStrlen(DAG, getCurSDLoc(), DAG.getRoot(), +                                getValue(Arg0), MachinePointerInfo(Arg0)); +  if (Res.first.getNode()) { +    processIntegerCallValue(I, Res.first, false); +    PendingLoads.push_back(Res.second); +    return true; +  } + +  return false; +} + +/// See if we can lower a strnlen call into an optimized form.  If so, return +/// true and lower it, otherwise return false and it will be lowered like a +/// normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitStrNLenCall(const CallInst &I) { +  const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1); + +  const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo(); +  std::pair<SDValue, SDValue> Res = +    TSI.EmitTargetCodeForStrnlen(DAG, getCurSDLoc(), DAG.getRoot(), +                                 getValue(Arg0), getValue(Arg1), +                                 MachinePointerInfo(Arg0)); +  if (Res.first.getNode()) { +    processIntegerCallValue(I, Res.first, false); +    PendingLoads.push_back(Res.second); +    return true; +  } + +  return false; +} + +/// See if we can lower a unary floating-point operation into an SDNode with +/// the specified Opcode.  If so, return true and lower it, otherwise return +/// false and it will be lowered like a normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitUnaryFloatCall(const CallInst &I, +                                              unsigned Opcode) { +  // We already checked this call's prototype; verify it doesn't modify errno. +  if (!I.onlyReadsMemory()) +    return false; + +  SDValue Tmp = getValue(I.getArgOperand(0)); +  setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), Tmp.getValueType(), Tmp)); +  return true; +} + +/// See if we can lower a binary floating-point operation into an SDNode with +/// the specified Opcode. If so, return true and lower it. Otherwise return +/// false, and it will be lowered like a normal call. +/// The caller already checked that \p I calls the appropriate LibFunc with a +/// correct prototype. +bool SelectionDAGBuilder::visitBinaryFloatCall(const CallInst &I, +                                               unsigned Opcode) { +  // We already checked this call's prototype; verify it doesn't modify errno. +  if (!I.onlyReadsMemory()) +    return false; + +  SDValue Tmp0 = getValue(I.getArgOperand(0)); +  SDValue Tmp1 = getValue(I.getArgOperand(1)); +  EVT VT = Tmp0.getValueType(); +  setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), VT, Tmp0, Tmp1)); +  return true; +} + +void SelectionDAGBuilder::visitCall(const CallInst &I) { +  // Handle inline assembly differently. +  if (isa<InlineAsm>(I.getCalledValue())) { +    visitInlineAsm(&I); +    return; +  } + +  MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI(); +  computeUsesVAFloatArgument(I, MMI); + +  const char *RenameFn = nullptr; +  if (Function *F = I.getCalledFunction()) { +    if (F->isDeclaration()) { +      if (const TargetIntrinsicInfo *II = TM.getIntrinsicInfo()) { +        if (unsigned IID = II->getIntrinsicID(F)) { +          RenameFn = visitIntrinsicCall(I, IID); +          if (!RenameFn) +            return; +        } +      } +      if (Intrinsic::ID IID = F->getIntrinsicID()) { +        RenameFn = visitIntrinsicCall(I, IID); +        if (!RenameFn) +          return; +      } +    } + +    // Check for well-known libc/libm calls.  If the function is internal, it +    // can't be a library call.  Don't do the check if marked as nobuiltin for +    // some reason. +    LibFunc Func; +    if (!I.isNoBuiltin() && !F->hasLocalLinkage() && F->hasName() && +        LibInfo->getLibFunc(*F, Func) && +        LibInfo->hasOptimizedCodeGen(Func)) { +      switch (Func) { +      default: break; +      case LibFunc_copysign: +      case LibFunc_copysignf: +      case LibFunc_copysignl: +        // We already checked this call's prototype; verify it doesn't modify +        // errno. +        if (I.onlyReadsMemory()) { +          SDValue LHS = getValue(I.getArgOperand(0)); +          SDValue RHS = getValue(I.getArgOperand(1)); +          setValue(&I, DAG.getNode(ISD::FCOPYSIGN, getCurSDLoc(), +                                   LHS.getValueType(), LHS, RHS)); +          return; +        } +        break; +      case LibFunc_fabs: +      case LibFunc_fabsf: +      case LibFunc_fabsl: +        if (visitUnaryFloatCall(I, ISD::FABS)) +          return; +        break; +      case LibFunc_fmin: +      case LibFunc_fminf: +      case LibFunc_fminl: +        if (visitBinaryFloatCall(I, ISD::FMINNUM)) +          return; +        break; +      case LibFunc_fmax: +      case LibFunc_fmaxf: +      case LibFunc_fmaxl: +        if (visitBinaryFloatCall(I, ISD::FMAXNUM)) +          return; +        break; +      case LibFunc_sin: +      case LibFunc_sinf: +      case LibFunc_sinl: +        if (visitUnaryFloatCall(I, ISD::FSIN)) +          return; +        break; +      case LibFunc_cos: +      case LibFunc_cosf: +      case LibFunc_cosl: +        if (visitUnaryFloatCall(I, ISD::FCOS)) +          return; +        break; +      case LibFunc_sqrt: +      case LibFunc_sqrtf: +      case LibFunc_sqrtl: +      case LibFunc_sqrt_finite: +      case LibFunc_sqrtf_finite: +      case LibFunc_sqrtl_finite: +        if (visitUnaryFloatCall(I, ISD::FSQRT)) +          return; +        break; +      case LibFunc_floor: +      case LibFunc_floorf: +      case LibFunc_floorl: +        if (visitUnaryFloatCall(I, ISD::FFLOOR)) +          return; +        break; +      case LibFunc_nearbyint: +      case LibFunc_nearbyintf: +      case LibFunc_nearbyintl: +        if (visitUnaryFloatCall(I, ISD::FNEARBYINT)) +          return; +        break; +      case LibFunc_ceil: +      case LibFunc_ceilf: +      case LibFunc_ceill: +        if (visitUnaryFloatCall(I, ISD::FCEIL)) +          return; +        break; +      case LibFunc_rint: +      case LibFunc_rintf: +      case LibFunc_rintl: +        if (visitUnaryFloatCall(I, ISD::FRINT)) +          return; +        break; +      case LibFunc_round: +      case LibFunc_roundf: +      case LibFunc_roundl: +        if (visitUnaryFloatCall(I, ISD::FROUND)) +          return; +        break; +      case LibFunc_trunc: +      case LibFunc_truncf: +      case LibFunc_truncl: +        if (visitUnaryFloatCall(I, ISD::FTRUNC)) +          return; +        break; +      case LibFunc_log2: +      case LibFunc_log2f: +      case LibFunc_log2l: +        if (visitUnaryFloatCall(I, ISD::FLOG2)) +          return; +        break; +      case LibFunc_exp2: +      case LibFunc_exp2f: +      case LibFunc_exp2l: +        if (visitUnaryFloatCall(I, ISD::FEXP2)) +          return; +        break; +      case LibFunc_memcmp: +        if (visitMemCmpCall(I)) +          return; +        break; +      case LibFunc_mempcpy: +        if (visitMemPCpyCall(I)) +          return; +        break; +      case LibFunc_memchr: +        if (visitMemChrCall(I)) +          return; +        break; +      case LibFunc_strcpy: +        if (visitStrCpyCall(I, false)) +          return; +        break; +      case LibFunc_stpcpy: +        if (visitStrCpyCall(I, true)) +          return; +        break; +      case LibFunc_strcmp: +        if (visitStrCmpCall(I)) +          return; +        break; +      case LibFunc_strlen: +        if (visitStrLenCall(I)) +          return; +        break; +      case LibFunc_strnlen: +        if (visitStrNLenCall(I)) +          return; +        break; +      } +    } +  } + +  SDValue Callee; +  if (!RenameFn) +    Callee = getValue(I.getCalledValue()); +  else +    Callee = DAG.getExternalSymbol( +        RenameFn, +        DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout())); + +  // Deopt bundles are lowered in LowerCallSiteWithDeoptBundle, and we don't +  // have to do anything here to lower funclet bundles. +  assert(!I.hasOperandBundlesOtherThan( +             {LLVMContext::OB_deopt, LLVMContext::OB_funclet}) && +         "Cannot lower calls with arbitrary operand bundles!"); + +  if (I.countOperandBundlesOfType(LLVMContext::OB_deopt)) +    LowerCallSiteWithDeoptBundle(&I, Callee, nullptr); +  else +    // Check if we can potentially perform a tail call. More detailed checking +    // is be done within LowerCallTo, after more information about the call is +    // known. +    LowerCallTo(&I, Callee, I.isTailCall()); +} + +namespace { + +/// AsmOperandInfo - This contains information for each constraint that we are +/// lowering. +class SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo { +public: +  /// CallOperand - If this is the result output operand or a clobber +  /// this is null, otherwise it is the incoming operand to the CallInst. +  /// This gets modified as the asm is processed. +  SDValue CallOperand; + +  /// AssignedRegs - If this is a register or register class operand, this +  /// contains the set of register corresponding to the operand. +  RegsForValue AssignedRegs; + +  explicit SDISelAsmOperandInfo(const TargetLowering::AsmOperandInfo &info) +    : TargetLowering::AsmOperandInfo(info), CallOperand(nullptr,0) { +  } + +  /// Whether or not this operand accesses memory +  bool hasMemory(const TargetLowering &TLI) const { +    // Indirect operand accesses access memory. +    if (isIndirect) +      return true; + +    for (const auto &Code : Codes) +      if (TLI.getConstraintType(Code) == TargetLowering::C_Memory) +        return true; + +    return false; +  } + +  /// getCallOperandValEVT - Return the EVT of the Value* that this operand +  /// corresponds to.  If there is no Value* for this operand, it returns +  /// MVT::Other. +  EVT getCallOperandValEVT(LLVMContext &Context, const TargetLowering &TLI, +                           const DataLayout &DL) const { +    if (!CallOperandVal) return MVT::Other; + +    if (isa<BasicBlock>(CallOperandVal)) +      return TLI.getPointerTy(DL); + +    llvm::Type *OpTy = CallOperandVal->getType(); + +    // FIXME: code duplicated from TargetLowering::ParseConstraints(). +    // If this is an indirect operand, the operand is a pointer to the +    // accessed type. +    if (isIndirect) { +      llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy); +      if (!PtrTy) +        report_fatal_error("Indirect operand for inline asm not a pointer!"); +      OpTy = PtrTy->getElementType(); +    } + +    // Look for vector wrapped in a struct. e.g. { <16 x i8> }. +    if (StructType *STy = dyn_cast<StructType>(OpTy)) +      if (STy->getNumElements() == 1) +        OpTy = STy->getElementType(0); + +    // If OpTy is not a single value, it may be a struct/union that we +    // can tile with integers. +    if (!OpTy->isSingleValueType() && OpTy->isSized()) { +      unsigned BitSize = DL.getTypeSizeInBits(OpTy); +      switch (BitSize) { +      default: break; +      case 1: +      case 8: +      case 16: +      case 32: +      case 64: +      case 128: +        OpTy = IntegerType::get(Context, BitSize); +        break; +      } +    } + +    return TLI.getValueType(DL, OpTy, true); +  } +}; + +typedef SmallVector<SDISelAsmOperandInfo,16> SDISelAsmOperandInfoVector; + +} // end anonymous namespace + +/// Make sure that the output operand \p OpInfo and its corresponding input +/// operand \p MatchingOpInfo have compatible constraint types (otherwise error +/// out). +static void patchMatchingInput(const SDISelAsmOperandInfo &OpInfo, +                               SDISelAsmOperandInfo &MatchingOpInfo, +                               SelectionDAG &DAG) { +  if (OpInfo.ConstraintVT == MatchingOpInfo.ConstraintVT) +    return; + +  const TargetRegisterInfo *TRI = DAG.getSubtarget().getRegisterInfo(); +  const auto &TLI = DAG.getTargetLoweringInfo(); + +  std::pair<unsigned, const TargetRegisterClass *> MatchRC = +      TLI.getRegForInlineAsmConstraint(TRI, OpInfo.ConstraintCode, +                                       OpInfo.ConstraintVT); +  std::pair<unsigned, const TargetRegisterClass *> InputRC = +      TLI.getRegForInlineAsmConstraint(TRI, MatchingOpInfo.ConstraintCode, +                                       MatchingOpInfo.ConstraintVT); +  if ((OpInfo.ConstraintVT.isInteger() != +       MatchingOpInfo.ConstraintVT.isInteger()) || +      (MatchRC.second != InputRC.second)) { +    // FIXME: error out in a more elegant fashion +    report_fatal_error("Unsupported asm: input constraint" +                       " with a matching output constraint of" +                       " incompatible type!"); +  } +  MatchingOpInfo.ConstraintVT = OpInfo.ConstraintVT; +} + +/// Get a direct memory input to behave well as an indirect operand. +/// This may introduce stores, hence the need for a \p Chain. +/// \return The (possibly updated) chain. +static SDValue getAddressForMemoryInput(SDValue Chain, const SDLoc &Location, +                                        SDISelAsmOperandInfo &OpInfo, +                                        SelectionDAG &DAG) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); + +  // If we don't have an indirect input, put it in the constpool if we can, +  // otherwise spill it to a stack slot. +  // TODO: This isn't quite right. We need to handle these according to +  // the addressing mode that the constraint wants. Also, this may take +  // an additional register for the computation and we don't want that +  // either. + +  // If the operand is a float, integer, or vector constant, spill to a +  // constant pool entry to get its address. +  const Value *OpVal = OpInfo.CallOperandVal; +  if (isa<ConstantFP>(OpVal) || isa<ConstantInt>(OpVal) || +      isa<ConstantVector>(OpVal) || isa<ConstantDataVector>(OpVal)) { +    OpInfo.CallOperand = DAG.getConstantPool( +        cast<Constant>(OpVal), TLI.getPointerTy(DAG.getDataLayout())); +    return Chain; +  } + +  // Otherwise, create a stack slot and emit a store to it before the asm. +  Type *Ty = OpVal->getType(); +  auto &DL = DAG.getDataLayout(); +  uint64_t TySize = DL.getTypeAllocSize(Ty); +  unsigned Align = DL.getPrefTypeAlignment(Ty); +  MachineFunction &MF = DAG.getMachineFunction(); +  int SSFI = MF.getFrameInfo().CreateStackObject(TySize, Align, false); +  SDValue StackSlot = DAG.getFrameIndex(SSFI, TLI.getFrameIndexTy(DL)); +  Chain = DAG.getStore(Chain, Location, OpInfo.CallOperand, StackSlot, +                       MachinePointerInfo::getFixedStack(MF, SSFI)); +  OpInfo.CallOperand = StackSlot; + +  return Chain; +} + +/// GetRegistersForValue - Assign registers (virtual or physical) for the +/// specified operand.  We prefer to assign virtual registers, to allow the +/// register allocator to handle the assignment process.  However, if the asm +/// uses features that we can't model on machineinstrs, we have SDISel do the +/// allocation.  This produces generally horrible, but correct, code. +/// +///   OpInfo describes the operand. +/// +static void GetRegistersForValue(SelectionDAG &DAG, const TargetLowering &TLI, +                                 const SDLoc &DL, +                                 SDISelAsmOperandInfo &OpInfo) { +  LLVMContext &Context = *DAG.getContext(); + +  MachineFunction &MF = DAG.getMachineFunction(); +  SmallVector<unsigned, 4> Regs; +  const TargetRegisterInfo &TRI = *MF.getSubtarget().getRegisterInfo(); + +  // If this is a constraint for a single physreg, or a constraint for a +  // register class, find it. +  std::pair<unsigned, const TargetRegisterClass *> PhysReg = +      TLI.getRegForInlineAsmConstraint(&TRI, OpInfo.ConstraintCode, +                                       OpInfo.ConstraintVT); + +  unsigned NumRegs = 1; +  if (OpInfo.ConstraintVT != MVT::Other) { +    // If this is a FP input in an integer register (or visa versa) insert a bit +    // cast of the input value.  More generally, handle any case where the input +    // value disagrees with the register class we plan to stick this in. +    if (OpInfo.Type == InlineAsm::isInput && PhysReg.second && +        !TRI.isTypeLegalForClass(*PhysReg.second, OpInfo.ConstraintVT)) { +      // Try to convert to the first EVT that the reg class contains.  If the +      // types are identical size, use a bitcast to convert (e.g. two differing +      // vector types). +      MVT RegVT = *TRI.legalclasstypes_begin(*PhysReg.second); +      if (RegVT.getSizeInBits() == OpInfo.CallOperand.getValueSizeInBits()) { +        OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL, +                                         RegVT, OpInfo.CallOperand); +        OpInfo.ConstraintVT = RegVT; +      } else if (RegVT.isInteger() && OpInfo.ConstraintVT.isFloatingPoint()) { +        // If the input is a FP value and we want it in FP registers, do a +        // bitcast to the corresponding integer type.  This turns an f64 value +        // into i64, which can be passed with two i32 values on a 32-bit +        // machine. +        RegVT = MVT::getIntegerVT(OpInfo.ConstraintVT.getSizeInBits()); +        OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL, +                                         RegVT, OpInfo.CallOperand); +        OpInfo.ConstraintVT = RegVT; +      } +    } + +    NumRegs = TLI.getNumRegisters(Context, OpInfo.ConstraintVT); +  } + +  MVT RegVT; +  EVT ValueVT = OpInfo.ConstraintVT; + +  // If this is a constraint for a specific physical register, like {r17}, +  // assign it now. +  if (unsigned AssignedReg = PhysReg.first) { +    const TargetRegisterClass *RC = PhysReg.second; +    if (OpInfo.ConstraintVT == MVT::Other) +      ValueVT = *TRI.legalclasstypes_begin(*RC); + +    // Get the actual register value type.  This is important, because the user +    // may have asked for (e.g.) the AX register in i32 type.  We need to +    // remember that AX is actually i16 to get the right extension. +    RegVT = *TRI.legalclasstypes_begin(*RC); + +    // This is a explicit reference to a physical register. +    Regs.push_back(AssignedReg); + +    // If this is an expanded reference, add the rest of the regs to Regs. +    if (NumRegs != 1) { +      TargetRegisterClass::iterator I = RC->begin(); +      for (; *I != AssignedReg; ++I) +        assert(I != RC->end() && "Didn't find reg!"); + +      // Already added the first reg. +      --NumRegs; ++I; +      for (; NumRegs; --NumRegs, ++I) { +        assert(I != RC->end() && "Ran out of registers to allocate!"); +        Regs.push_back(*I); +      } +    } + +    OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT); +    return; +  } + +  // Otherwise, if this was a reference to an LLVM register class, create vregs +  // for this reference. +  if (const TargetRegisterClass *RC = PhysReg.second) { +    RegVT = *TRI.legalclasstypes_begin(*RC); +    if (OpInfo.ConstraintVT == MVT::Other) +      ValueVT = RegVT; + +    // Create the appropriate number of virtual registers. +    MachineRegisterInfo &RegInfo = MF.getRegInfo(); +    for (; NumRegs; --NumRegs) +      Regs.push_back(RegInfo.createVirtualRegister(RC)); + +    OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT); +    return; +  } + +  // Otherwise, we couldn't allocate enough registers for this. +} + +static unsigned +findMatchingInlineAsmOperand(unsigned OperandNo, +                             const std::vector<SDValue> &AsmNodeOperands) { +  // Scan until we find the definition we already emitted of this operand. +  unsigned CurOp = InlineAsm::Op_FirstOperand; +  for (; OperandNo; --OperandNo) { +    // Advance to the next operand. +    unsigned OpFlag = +        cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue(); +    assert((InlineAsm::isRegDefKind(OpFlag) || +            InlineAsm::isRegDefEarlyClobberKind(OpFlag) || +            InlineAsm::isMemKind(OpFlag)) && +           "Skipped past definitions?"); +    CurOp += InlineAsm::getNumOperandRegisters(OpFlag) + 1; +  } +  return CurOp; +} + +/// Fill \p Regs with \p NumRegs new virtual registers of type \p RegVT +/// \return true if it has succeeded, false otherwise +static bool createVirtualRegs(SmallVector<unsigned, 4> &Regs, unsigned NumRegs, +                              MVT RegVT, SelectionDAG &DAG) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  MachineRegisterInfo &RegInfo = DAG.getMachineFunction().getRegInfo(); +  for (unsigned i = 0, e = NumRegs; i != e; ++i) { +    if (const TargetRegisterClass *RC = TLI.getRegClassFor(RegVT)) +      Regs.push_back(RegInfo.createVirtualRegister(RC)); +    else +      return false; +  } +  return true; +} + +class ExtraFlags { +  unsigned Flags = 0; + +public: +  explicit ExtraFlags(ImmutableCallSite CS) { +    const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue()); +    if (IA->hasSideEffects()) +      Flags |= InlineAsm::Extra_HasSideEffects; +    if (IA->isAlignStack()) +      Flags |= InlineAsm::Extra_IsAlignStack; +    if (CS.isConvergent()) +      Flags |= InlineAsm::Extra_IsConvergent; +    Flags |= IA->getDialect() * InlineAsm::Extra_AsmDialect; +  } + +  void update(const llvm::TargetLowering::AsmOperandInfo &OpInfo) { +    // Ideally, we would only check against memory constraints.  However, the +    // meaning of an Other constraint can be target-specific and we can't easily +    // reason about it.  Therefore, be conservative and set MayLoad/MayStore +    // for Other constraints as well. +    if (OpInfo.ConstraintType == TargetLowering::C_Memory || +        OpInfo.ConstraintType == TargetLowering::C_Other) { +      if (OpInfo.Type == InlineAsm::isInput) +        Flags |= InlineAsm::Extra_MayLoad; +      else if (OpInfo.Type == InlineAsm::isOutput) +        Flags |= InlineAsm::Extra_MayStore; +      else if (OpInfo.Type == InlineAsm::isClobber) +        Flags |= (InlineAsm::Extra_MayLoad | InlineAsm::Extra_MayStore); +    } +  } + +  unsigned get() const { return Flags; } +}; + +/// visitInlineAsm - Handle a call to an InlineAsm object. +/// +void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) { +  const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue()); + +  /// ConstraintOperands - Information about all of the constraints. +  SDISelAsmOperandInfoVector ConstraintOperands; + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  TargetLowering::AsmOperandInfoVector TargetConstraints = TLI.ParseConstraints( +      DAG.getDataLayout(), DAG.getSubtarget().getRegisterInfo(), CS); + +  bool hasMemory = false; + +  // Remember the HasSideEffect, AlignStack, AsmDialect, MayLoad and MayStore +  ExtraFlags ExtraInfo(CS); + +  unsigned ArgNo = 0;   // ArgNo - The argument of the CallInst. +  unsigned ResNo = 0;   // ResNo - The result number of the next output. +  for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) { +    ConstraintOperands.push_back(SDISelAsmOperandInfo(TargetConstraints[i])); +    SDISelAsmOperandInfo &OpInfo = ConstraintOperands.back(); + +    MVT OpVT = MVT::Other; + +    // Compute the value type for each operand. +    if (OpInfo.Type == InlineAsm::isInput || +        (OpInfo.Type == InlineAsm::isOutput && OpInfo.isIndirect)) { +      OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++)); + +      // Process the call argument. BasicBlocks are labels, currently appearing +      // only in asm's. +      if (const BasicBlock *BB = dyn_cast<BasicBlock>(OpInfo.CallOperandVal)) { +        OpInfo.CallOperand = DAG.getBasicBlock(FuncInfo.MBBMap[BB]); +      } else { +        OpInfo.CallOperand = getValue(OpInfo.CallOperandVal); +      } + +      OpVT = +          OpInfo +              .getCallOperandValEVT(*DAG.getContext(), TLI, DAG.getDataLayout()) +              .getSimpleVT(); +    } + +    if (OpInfo.Type == InlineAsm::isOutput && !OpInfo.isIndirect) { +      // The return value of the call is this value.  As such, there is no +      // corresponding argument. +      assert(!CS.getType()->isVoidTy() && "Bad inline asm!"); +      if (StructType *STy = dyn_cast<StructType>(CS.getType())) { +        OpVT = TLI.getSimpleValueType(DAG.getDataLayout(), +                                      STy->getElementType(ResNo)); +      } else { +        assert(ResNo == 0 && "Asm only has one result!"); +        OpVT = TLI.getSimpleValueType(DAG.getDataLayout(), CS.getType()); +      } +      ++ResNo; +    } + +    OpInfo.ConstraintVT = OpVT; + +    if (!hasMemory) +      hasMemory = OpInfo.hasMemory(TLI); + +    // Determine if this InlineAsm MayLoad or MayStore based on the constraints. +    // FIXME: Could we compute this on OpInfo rather than TargetConstraints[i]? +    auto TargetConstraint = TargetConstraints[i]; + +    // Compute the constraint code and ConstraintType to use. +    TLI.ComputeConstraintToUse(TargetConstraint, SDValue()); + +    ExtraInfo.update(TargetConstraint); +  } + +  SDValue Chain, Flag; + +  // We won't need to flush pending loads if this asm doesn't touch +  // memory and is nonvolatile. +  if (hasMemory || IA->hasSideEffects()) +    Chain = getRoot(); +  else +    Chain = DAG.getRoot(); + +  // Second pass over the constraints: compute which constraint option to use +  // and assign registers to constraints that want a specific physreg. +  for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { +    SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; + +    // If this is an output operand with a matching input operand, look up the +    // matching input. If their types mismatch, e.g. one is an integer, the +    // other is floating point, or their sizes are different, flag it as an +    // error. +    if (OpInfo.hasMatchingInput()) { +      SDISelAsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput]; +      patchMatchingInput(OpInfo, Input, DAG); +    } + +    // Compute the constraint code and ConstraintType to use. +    TLI.ComputeConstraintToUse(OpInfo, OpInfo.CallOperand, &DAG); + +    if (OpInfo.ConstraintType == TargetLowering::C_Memory && +        OpInfo.Type == InlineAsm::isClobber) +      continue; + +    // If this is a memory input, and if the operand is not indirect, do what we +    // need to to provide an address for the memory input. +    if (OpInfo.ConstraintType == TargetLowering::C_Memory && +        !OpInfo.isIndirect) { +      assert((OpInfo.isMultipleAlternative || +              (OpInfo.Type == InlineAsm::isInput)) && +             "Can only indirectify direct input operands!"); + +      // Memory operands really want the address of the value. +      Chain = getAddressForMemoryInput(Chain, getCurSDLoc(), OpInfo, DAG); + +      // There is no longer a Value* corresponding to this operand. +      OpInfo.CallOperandVal = nullptr; + +      // It is now an indirect operand. +      OpInfo.isIndirect = true; +    } + +    // If this constraint is for a specific register, allocate it before +    // anything else. +    if (OpInfo.ConstraintType == TargetLowering::C_Register) +      GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo); +  } + +  // Third pass - Loop over all of the operands, assigning virtual or physregs +  // to register class operands. +  for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { +    SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; + +    // C_Register operands have already been allocated, Other/Memory don't need +    // to be. +    if (OpInfo.ConstraintType == TargetLowering::C_RegisterClass) +      GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo); +  } + +  // AsmNodeOperands - The operands for the ISD::INLINEASM node. +  std::vector<SDValue> AsmNodeOperands; +  AsmNodeOperands.push_back(SDValue());  // reserve space for input chain +  AsmNodeOperands.push_back(DAG.getTargetExternalSymbol( +      IA->getAsmString().c_str(), TLI.getPointerTy(DAG.getDataLayout()))); + +  // If we have a !srcloc metadata node associated with it, we want to attach +  // this to the ultimately generated inline asm machineinstr.  To do this, we +  // pass in the third operand as this (potentially null) inline asm MDNode. +  const MDNode *SrcLoc = CS.getInstruction()->getMetadata("srcloc"); +  AsmNodeOperands.push_back(DAG.getMDNode(SrcLoc)); + +  // Remember the HasSideEffect, AlignStack, AsmDialect, MayLoad and MayStore +  // bits as operand 3. +  AsmNodeOperands.push_back(DAG.getTargetConstant( +      ExtraInfo.get(), getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout()))); + +  // Loop over all of the inputs, copying the operand values into the +  // appropriate registers and processing the output regs. +  RegsForValue RetValRegs; + +  // IndirectStoresToEmit - The set of stores to emit after the inline asm node. +  std::vector<std::pair<RegsForValue, Value*> > IndirectStoresToEmit; + +  for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { +    SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; + +    switch (OpInfo.Type) { +    case InlineAsm::isOutput: { +      if (OpInfo.ConstraintType != TargetLowering::C_RegisterClass && +          OpInfo.ConstraintType != TargetLowering::C_Register) { +        // Memory output, or 'other' output (e.g. 'X' constraint). +        assert(OpInfo.isIndirect && "Memory output must be indirect operand"); + +        unsigned ConstraintID = +            TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode); +        assert(ConstraintID != InlineAsm::Constraint_Unknown && +               "Failed to convert memory constraint code to constraint id."); + +        // Add information to the INLINEASM node to know about this output. +        unsigned OpFlags = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1); +        OpFlags = InlineAsm::getFlagWordForMem(OpFlags, ConstraintID); +        AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlags, getCurSDLoc(), +                                                        MVT::i32)); +        AsmNodeOperands.push_back(OpInfo.CallOperand); +        break; +      } + +      // Otherwise, this is a register or register class output. + +      // Copy the output from the appropriate register.  Find a register that +      // we can use. +      if (OpInfo.AssignedRegs.Regs.empty()) { +        emitInlineAsmError( +            CS, "couldn't allocate output register for constraint '" + +                    Twine(OpInfo.ConstraintCode) + "'"); +        return; +      } + +      // If this is an indirect operand, store through the pointer after the +      // asm. +      if (OpInfo.isIndirect) { +        IndirectStoresToEmit.push_back(std::make_pair(OpInfo.AssignedRegs, +                                                      OpInfo.CallOperandVal)); +      } else { +        // This is the result value of the call. +        assert(!CS.getType()->isVoidTy() && "Bad inline asm!"); +        // Concatenate this output onto the outputs list. +        RetValRegs.append(OpInfo.AssignedRegs); +      } + +      // Add information to the INLINEASM node to know that this register is +      // set. +      OpInfo.AssignedRegs +          .AddInlineAsmOperands(OpInfo.isEarlyClobber +                                    ? InlineAsm::Kind_RegDefEarlyClobber +                                    : InlineAsm::Kind_RegDef, +                                false, 0, getCurSDLoc(), DAG, AsmNodeOperands); +      break; +    } +    case InlineAsm::isInput: { +      SDValue InOperandVal = OpInfo.CallOperand; + +      if (OpInfo.isMatchingInputConstraint()) { +        // If this is required to match an output register we have already set, +        // just use its register. +        auto CurOp = findMatchingInlineAsmOperand(OpInfo.getMatchedOperand(), +                                                  AsmNodeOperands); +        unsigned OpFlag = +          cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue(); +        if (InlineAsm::isRegDefKind(OpFlag) || +            InlineAsm::isRegDefEarlyClobberKind(OpFlag)) { +          // Add (OpFlag&0xffff)>>3 registers to MatchedRegs. +          if (OpInfo.isIndirect) { +            // This happens on gcc/testsuite/gcc.dg/pr8788-1.c +            emitInlineAsmError(CS, "inline asm not supported yet:" +                                   " don't know how to handle tied " +                                   "indirect register inputs"); +            return; +          } + +          MVT RegVT = AsmNodeOperands[CurOp+1].getSimpleValueType(); +          SmallVector<unsigned, 4> Regs; + +          if (!createVirtualRegs(Regs, +                                 InlineAsm::getNumOperandRegisters(OpFlag), +                                 RegVT, DAG)) { +            emitInlineAsmError(CS, "inline asm error: This value type register " +                                   "class is not natively supported!"); +            return; +          } + +          RegsForValue MatchedRegs(Regs, RegVT, InOperandVal.getValueType()); + +          SDLoc dl = getCurSDLoc(); +          // Use the produced MatchedRegs object to +          MatchedRegs.getCopyToRegs(InOperandVal, DAG, dl, Chain, &Flag, +                                    CS.getInstruction()); +          MatchedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse, +                                           true, OpInfo.getMatchedOperand(), dl, +                                           DAG, AsmNodeOperands); +          break; +        } + +        assert(InlineAsm::isMemKind(OpFlag) && "Unknown matching constraint!"); +        assert(InlineAsm::getNumOperandRegisters(OpFlag) == 1 && +               "Unexpected number of operands"); +        // Add information to the INLINEASM node to know about this input. +        // See InlineAsm.h isUseOperandTiedToDef. +        OpFlag = InlineAsm::convertMemFlagWordToMatchingFlagWord(OpFlag); +        OpFlag = InlineAsm::getFlagWordForMatchingOp(OpFlag, +                                                    OpInfo.getMatchedOperand()); +        AsmNodeOperands.push_back(DAG.getTargetConstant( +            OpFlag, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout()))); +        AsmNodeOperands.push_back(AsmNodeOperands[CurOp+1]); +        break; +      } + +      // Treat indirect 'X' constraint as memory. +      if (OpInfo.ConstraintType == TargetLowering::C_Other && +          OpInfo.isIndirect) +        OpInfo.ConstraintType = TargetLowering::C_Memory; + +      if (OpInfo.ConstraintType == TargetLowering::C_Other) { +        std::vector<SDValue> Ops; +        TLI.LowerAsmOperandForConstraint(InOperandVal, OpInfo.ConstraintCode, +                                          Ops, DAG); +        if (Ops.empty()) { +          emitInlineAsmError(CS, "invalid operand for inline asm constraint '" + +                                     Twine(OpInfo.ConstraintCode) + "'"); +          return; +        } + +        // Add information to the INLINEASM node to know about this input. +        unsigned ResOpType = +          InlineAsm::getFlagWord(InlineAsm::Kind_Imm, Ops.size()); +        AsmNodeOperands.push_back(DAG.getTargetConstant( +            ResOpType, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout()))); +        AsmNodeOperands.insert(AsmNodeOperands.end(), Ops.begin(), Ops.end()); +        break; +      } + +      if (OpInfo.ConstraintType == TargetLowering::C_Memory) { +        assert(OpInfo.isIndirect && "Operand must be indirect to be a mem!"); +        assert(InOperandVal.getValueType() == +                   TLI.getPointerTy(DAG.getDataLayout()) && +               "Memory operands expect pointer values"); + +        unsigned ConstraintID = +            TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode); +        assert(ConstraintID != InlineAsm::Constraint_Unknown && +               "Failed to convert memory constraint code to constraint id."); + +        // Add information to the INLINEASM node to know about this input. +        unsigned ResOpType = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1); +        ResOpType = InlineAsm::getFlagWordForMem(ResOpType, ConstraintID); +        AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType, +                                                        getCurSDLoc(), +                                                        MVT::i32)); +        AsmNodeOperands.push_back(InOperandVal); +        break; +      } + +      assert((OpInfo.ConstraintType == TargetLowering::C_RegisterClass || +              OpInfo.ConstraintType == TargetLowering::C_Register) && +             "Unknown constraint type!"); + +      // TODO: Support this. +      if (OpInfo.isIndirect) { +        emitInlineAsmError( +            CS, "Don't know how to handle indirect register inputs yet " +                "for constraint '" + +                    Twine(OpInfo.ConstraintCode) + "'"); +        return; +      } + +      // Copy the input into the appropriate registers. +      if (OpInfo.AssignedRegs.Regs.empty()) { +        emitInlineAsmError(CS, "couldn't allocate input reg for constraint '" + +                                   Twine(OpInfo.ConstraintCode) + "'"); +        return; +      } + +      SDLoc dl = getCurSDLoc(); + +      OpInfo.AssignedRegs.getCopyToRegs(InOperandVal, DAG, dl, +                                        Chain, &Flag, CS.getInstruction()); + +      OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse, false, 0, +                                               dl, DAG, AsmNodeOperands); +      break; +    } +    case InlineAsm::isClobber: { +      // Add the clobbered value to the operand list, so that the register +      // allocator is aware that the physreg got clobbered. +      if (!OpInfo.AssignedRegs.Regs.empty()) +        OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_Clobber, +                                                 false, 0, getCurSDLoc(), DAG, +                                                 AsmNodeOperands); +      break; +    } +    } +  } + +  // Finish up input operands.  Set the input chain and add the flag last. +  AsmNodeOperands[InlineAsm::Op_InputChain] = Chain; +  if (Flag.getNode()) AsmNodeOperands.push_back(Flag); + +  Chain = DAG.getNode(ISD::INLINEASM, getCurSDLoc(), +                      DAG.getVTList(MVT::Other, MVT::Glue), AsmNodeOperands); +  Flag = Chain.getValue(1); + +  // If this asm returns a register value, copy the result from that register +  // and set it as the value of the call. +  if (!RetValRegs.Regs.empty()) { +    SDValue Val = RetValRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), +                                             Chain, &Flag, CS.getInstruction()); + +    // FIXME: Why don't we do this for inline asms with MRVs? +    if (CS.getType()->isSingleValueType() && CS.getType()->isSized()) { +      EVT ResultType = TLI.getValueType(DAG.getDataLayout(), CS.getType()); + +      // If any of the results of the inline asm is a vector, it may have the +      // wrong width/num elts.  This can happen for register classes that can +      // contain multiple different value types.  The preg or vreg allocated may +      // not have the same VT as was expected.  Convert it to the right type +      // with bit_convert. +      if (ResultType != Val.getValueType() && Val.getValueType().isVector()) { +        Val = DAG.getNode(ISD::BITCAST, getCurSDLoc(), +                          ResultType, Val); + +      } else if (ResultType != Val.getValueType() && +                 ResultType.isInteger() && Val.getValueType().isInteger()) { +        // If a result value was tied to an input value, the computed result may +        // have a wider width than the expected result.  Extract the relevant +        // portion. +        Val = DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), ResultType, Val); +      } + +      assert(ResultType == Val.getValueType() && "Asm result value mismatch!"); +    } + +    setValue(CS.getInstruction(), Val); +    // Don't need to use this as a chain in this case. +    if (!IA->hasSideEffects() && !hasMemory && IndirectStoresToEmit.empty()) +      return; +  } + +  std::vector<std::pair<SDValue, const Value *> > StoresToEmit; + +  // Process indirect outputs, first output all of the flagged copies out of +  // physregs. +  for (unsigned i = 0, e = IndirectStoresToEmit.size(); i != e; ++i) { +    RegsForValue &OutRegs = IndirectStoresToEmit[i].first; +    const Value *Ptr = IndirectStoresToEmit[i].second; +    SDValue OutVal = OutRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), +                                             Chain, &Flag, IA); +    StoresToEmit.push_back(std::make_pair(OutVal, Ptr)); +  } + +  // Emit the non-flagged stores from the physregs. +  SmallVector<SDValue, 8> OutChains; +  for (unsigned i = 0, e = StoresToEmit.size(); i != e; ++i) { +    SDValue Val = DAG.getStore(Chain, getCurSDLoc(), StoresToEmit[i].first, +                               getValue(StoresToEmit[i].second), +                               MachinePointerInfo(StoresToEmit[i].second)); +    OutChains.push_back(Val); +  } + +  if (!OutChains.empty()) +    Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, OutChains); + +  DAG.setRoot(Chain); +} + +void SelectionDAGBuilder::emitInlineAsmError(ImmutableCallSite CS, +                                             const Twine &Message) { +  LLVMContext &Ctx = *DAG.getContext(); +  Ctx.emitError(CS.getInstruction(), Message); + +  // Make sure we leave the DAG in a valid state +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  auto VT = TLI.getValueType(DAG.getDataLayout(), CS.getType()); +  setValue(CS.getInstruction(), DAG.getUNDEF(VT)); +} + +void SelectionDAGBuilder::visitVAStart(const CallInst &I) { +  DAG.setRoot(DAG.getNode(ISD::VASTART, getCurSDLoc(), +                          MVT::Other, getRoot(), +                          getValue(I.getArgOperand(0)), +                          DAG.getSrcValue(I.getArgOperand(0)))); +} + +void SelectionDAGBuilder::visitVAArg(const VAArgInst &I) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  const DataLayout &DL = DAG.getDataLayout(); +  SDValue V = DAG.getVAArg(TLI.getValueType(DAG.getDataLayout(), I.getType()), +                           getCurSDLoc(), getRoot(), getValue(I.getOperand(0)), +                           DAG.getSrcValue(I.getOperand(0)), +                           DL.getABITypeAlignment(I.getType())); +  setValue(&I, V); +  DAG.setRoot(V.getValue(1)); +} + +void SelectionDAGBuilder::visitVAEnd(const CallInst &I) { +  DAG.setRoot(DAG.getNode(ISD::VAEND, getCurSDLoc(), +                          MVT::Other, getRoot(), +                          getValue(I.getArgOperand(0)), +                          DAG.getSrcValue(I.getArgOperand(0)))); +} + +void SelectionDAGBuilder::visitVACopy(const CallInst &I) { +  DAG.setRoot(DAG.getNode(ISD::VACOPY, getCurSDLoc(), +                          MVT::Other, getRoot(), +                          getValue(I.getArgOperand(0)), +                          getValue(I.getArgOperand(1)), +                          DAG.getSrcValue(I.getArgOperand(0)), +                          DAG.getSrcValue(I.getArgOperand(1)))); +} + +SDValue SelectionDAGBuilder::lowerRangeToAssertZExt(SelectionDAG &DAG, +                                                    const Instruction &I, +                                                    SDValue Op) { +  const MDNode *Range = I.getMetadata(LLVMContext::MD_range); +  if (!Range) +    return Op; + +  ConstantRange CR = getConstantRangeFromMetadata(*Range); +  if (CR.isFullSet() || CR.isEmptySet() || CR.isWrappedSet()) +    return Op; + +  APInt Lo = CR.getUnsignedMin(); +  if (!Lo.isMinValue()) +    return Op; + +  APInt Hi = CR.getUnsignedMax(); +  unsigned Bits = Hi.getActiveBits(); + +  EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), Bits); + +  SDLoc SL = getCurSDLoc(); + +  SDValue ZExt = DAG.getNode(ISD::AssertZext, SL, Op.getValueType(), Op, +                             DAG.getValueType(SmallVT)); +  unsigned NumVals = Op.getNode()->getNumValues(); +  if (NumVals == 1) +    return ZExt; + +  SmallVector<SDValue, 4> Ops; + +  Ops.push_back(ZExt); +  for (unsigned I = 1; I != NumVals; ++I) +    Ops.push_back(Op.getValue(I)); + +  return DAG.getMergeValues(Ops, SL); +} + +/// \brief Populate a CallLowerinInfo (into \p CLI) based on the properties of +/// the call being lowered. +/// +/// This is a helper for lowering intrinsics that follow a target calling +/// convention or require stack pointer adjustment. Only a subset of the +/// intrinsic's operands need to participate in the calling convention. +void SelectionDAGBuilder::populateCallLoweringInfo( +    TargetLowering::CallLoweringInfo &CLI, ImmutableCallSite CS, +    unsigned ArgIdx, unsigned NumArgs, SDValue Callee, Type *ReturnTy, +    bool IsPatchPoint) { +  TargetLowering::ArgListTy Args; +  Args.reserve(NumArgs); + +  // Populate the argument list. +  // Attributes for args start at offset 1, after the return attribute. +  for (unsigned ArgI = ArgIdx, ArgE = ArgIdx + NumArgs; +       ArgI != ArgE; ++ArgI) { +    const Value *V = CS->getOperand(ArgI); + +    assert(!V->getType()->isEmptyTy() && "Empty type passed to intrinsic."); + +    TargetLowering::ArgListEntry Entry; +    Entry.Node = getValue(V); +    Entry.Ty = V->getType(); +    Entry.setAttributes(&CS, ArgIdx); +    Args.push_back(Entry); +  } + +  CLI.setDebugLoc(getCurSDLoc()) +      .setChain(getRoot()) +      .setCallee(CS.getCallingConv(), ReturnTy, Callee, std::move(Args)) +      .setDiscardResult(CS->use_empty()) +      .setIsPatchPoint(IsPatchPoint); +} + +/// \brief Add a stack map intrinsic call's live variable operands to a stackmap +/// or patchpoint target node's operand list. +/// +/// Constants are converted to TargetConstants purely as an optimization to +/// avoid constant materialization and register allocation. +/// +/// FrameIndex operands are converted to TargetFrameIndex so that ISEL does not +/// generate addess computation nodes, and so ExpandISelPseudo can convert the +/// TargetFrameIndex into a DirectMemRefOp StackMap location. This avoids +/// address materialization and register allocation, but may also be required +/// for correctness. If a StackMap (or PatchPoint) intrinsic directly uses an +/// alloca in the entry block, then the runtime may assume that the alloca's +/// StackMap location can be read immediately after compilation and that the +/// location is valid at any point during execution (this is similar to the +/// assumption made by the llvm.gcroot intrinsic). If the alloca's location were +/// only available in a register, then the runtime would need to trap when +/// execution reaches the StackMap in order to read the alloca's location. +static void addStackMapLiveVars(ImmutableCallSite CS, unsigned StartIdx, +                                const SDLoc &DL, SmallVectorImpl<SDValue> &Ops, +                                SelectionDAGBuilder &Builder) { +  for (unsigned i = StartIdx, e = CS.arg_size(); i != e; ++i) { +    SDValue OpVal = Builder.getValue(CS.getArgument(i)); +    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(OpVal)) { +      Ops.push_back( +        Builder.DAG.getTargetConstant(StackMaps::ConstantOp, DL, MVT::i64)); +      Ops.push_back( +        Builder.DAG.getTargetConstant(C->getSExtValue(), DL, MVT::i64)); +    } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(OpVal)) { +      const TargetLowering &TLI = Builder.DAG.getTargetLoweringInfo(); +      Ops.push_back(Builder.DAG.getTargetFrameIndex( +          FI->getIndex(), TLI.getFrameIndexTy(Builder.DAG.getDataLayout()))); +    } else +      Ops.push_back(OpVal); +  } +} + +/// \brief Lower llvm.experimental.stackmap directly to its target opcode. +void SelectionDAGBuilder::visitStackmap(const CallInst &CI) { +  // void @llvm.experimental.stackmap(i32 <id>, i32 <numShadowBytes>, +  //                                  [live variables...]) + +  assert(CI.getType()->isVoidTy() && "Stackmap cannot return a value."); + +  SDValue Chain, InFlag, Callee, NullPtr; +  SmallVector<SDValue, 32> Ops; + +  SDLoc DL = getCurSDLoc(); +  Callee = getValue(CI.getCalledValue()); +  NullPtr = DAG.getIntPtrConstant(0, DL, true); + +  // The stackmap intrinsic only records the live variables (the arguemnts +  // passed to it) and emits NOPS (if requested). Unlike the patchpoint +  // intrinsic, this won't be lowered to a function call. This means we don't +  // have to worry about calling conventions and target specific lowering code. +  // Instead we perform the call lowering right here. +  // +  // chain, flag = CALLSEQ_START(chain, 0, 0) +  // chain, flag = STACKMAP(id, nbytes, ..., chain, flag) +  // chain, flag = CALLSEQ_END(chain, 0, 0, flag) +  // +  Chain = DAG.getCALLSEQ_START(getRoot(), 0, 0, DL); +  InFlag = Chain.getValue(1); + +  // Add the <id> and <numBytes> constants. +  SDValue IDVal = getValue(CI.getOperand(PatchPointOpers::IDPos)); +  Ops.push_back(DAG.getTargetConstant( +                  cast<ConstantSDNode>(IDVal)->getZExtValue(), DL, MVT::i64)); +  SDValue NBytesVal = getValue(CI.getOperand(PatchPointOpers::NBytesPos)); +  Ops.push_back(DAG.getTargetConstant( +                  cast<ConstantSDNode>(NBytesVal)->getZExtValue(), DL, +                  MVT::i32)); + +  // Push live variables for the stack map. +  addStackMapLiveVars(&CI, 2, DL, Ops, *this); + +  // We are not pushing any register mask info here on the operands list, +  // because the stackmap doesn't clobber anything. + +  // Push the chain and the glue flag. +  Ops.push_back(Chain); +  Ops.push_back(InFlag); + +  // Create the STACKMAP node. +  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); +  SDNode *SM = DAG.getMachineNode(TargetOpcode::STACKMAP, DL, NodeTys, Ops); +  Chain = SDValue(SM, 0); +  InFlag = Chain.getValue(1); + +  Chain = DAG.getCALLSEQ_END(Chain, NullPtr, NullPtr, InFlag, DL); + +  // Stackmaps don't generate values, so nothing goes into the NodeMap. + +  // Set the root to the target-lowered call chain. +  DAG.setRoot(Chain); + +  // Inform the Frame Information that we have a stackmap in this function. +  FuncInfo.MF->getFrameInfo().setHasStackMap(); +} + +/// \brief Lower llvm.experimental.patchpoint directly to its target opcode. +void SelectionDAGBuilder::visitPatchpoint(ImmutableCallSite CS, +                                          const BasicBlock *EHPadBB) { +  // void|i64 @llvm.experimental.patchpoint.void|i64(i64 <id>, +  //                                                 i32 <numBytes>, +  //                                                 i8* <target>, +  //                                                 i32 <numArgs>, +  //                                                 [Args...], +  //                                                 [live variables...]) + +  CallingConv::ID CC = CS.getCallingConv(); +  bool IsAnyRegCC = CC == CallingConv::AnyReg; +  bool HasDef = !CS->getType()->isVoidTy(); +  SDLoc dl = getCurSDLoc(); +  SDValue Callee = getValue(CS->getOperand(PatchPointOpers::TargetPos)); + +  // Handle immediate and symbolic callees. +  if (auto* ConstCallee = dyn_cast<ConstantSDNode>(Callee)) +    Callee = DAG.getIntPtrConstant(ConstCallee->getZExtValue(), dl, +                                   /*isTarget=*/true); +  else if (auto* SymbolicCallee = dyn_cast<GlobalAddressSDNode>(Callee)) +    Callee =  DAG.getTargetGlobalAddress(SymbolicCallee->getGlobal(), +                                         SDLoc(SymbolicCallee), +                                         SymbolicCallee->getValueType(0)); + +  // Get the real number of arguments participating in the call <numArgs> +  SDValue NArgVal = getValue(CS.getArgument(PatchPointOpers::NArgPos)); +  unsigned NumArgs = cast<ConstantSDNode>(NArgVal)->getZExtValue(); + +  // Skip the four meta args: <id>, <numNopBytes>, <target>, <numArgs> +  // Intrinsics include all meta-operands up to but not including CC. +  unsigned NumMetaOpers = PatchPointOpers::CCPos; +  assert(CS.arg_size() >= NumMetaOpers + NumArgs && +         "Not enough arguments provided to the patchpoint intrinsic"); + +  // For AnyRegCC the arguments are lowered later on manually. +  unsigned NumCallArgs = IsAnyRegCC ? 0 : NumArgs; +  Type *ReturnTy = +    IsAnyRegCC ? Type::getVoidTy(*DAG.getContext()) : CS->getType(); + +  TargetLowering::CallLoweringInfo CLI(DAG); +  populateCallLoweringInfo(CLI, CS, NumMetaOpers, NumCallArgs, Callee, ReturnTy, +                           true); +  std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB); + +  SDNode *CallEnd = Result.second.getNode(); +  if (HasDef && (CallEnd->getOpcode() == ISD::CopyFromReg)) +    CallEnd = CallEnd->getOperand(0).getNode(); + +  /// Get a call instruction from the call sequence chain. +  /// Tail calls are not allowed. +  assert(CallEnd->getOpcode() == ISD::CALLSEQ_END && +         "Expected a callseq node."); +  SDNode *Call = CallEnd->getOperand(0).getNode(); +  bool HasGlue = Call->getGluedNode(); + +  // Replace the target specific call node with the patchable intrinsic. +  SmallVector<SDValue, 8> Ops; + +  // Add the <id> and <numBytes> constants. +  SDValue IDVal = getValue(CS->getOperand(PatchPointOpers::IDPos)); +  Ops.push_back(DAG.getTargetConstant( +                  cast<ConstantSDNode>(IDVal)->getZExtValue(), dl, MVT::i64)); +  SDValue NBytesVal = getValue(CS->getOperand(PatchPointOpers::NBytesPos)); +  Ops.push_back(DAG.getTargetConstant( +                  cast<ConstantSDNode>(NBytesVal)->getZExtValue(), dl, +                  MVT::i32)); + +  // Add the callee. +  Ops.push_back(Callee); + +  // Adjust <numArgs> to account for any arguments that have been passed on the +  // stack instead. +  // Call Node: Chain, Target, {Args}, RegMask, [Glue] +  unsigned NumCallRegArgs = Call->getNumOperands() - (HasGlue ? 4 : 3); +  NumCallRegArgs = IsAnyRegCC ? NumArgs : NumCallRegArgs; +  Ops.push_back(DAG.getTargetConstant(NumCallRegArgs, dl, MVT::i32)); + +  // Add the calling convention +  Ops.push_back(DAG.getTargetConstant((unsigned)CC, dl, MVT::i32)); + +  // Add the arguments we omitted previously. The register allocator should +  // place these in any free register. +  if (IsAnyRegCC) +    for (unsigned i = NumMetaOpers, e = NumMetaOpers + NumArgs; i != e; ++i) +      Ops.push_back(getValue(CS.getArgument(i))); + +  // Push the arguments from the call instruction up to the register mask. +  SDNode::op_iterator e = HasGlue ? Call->op_end()-2 : Call->op_end()-1; +  Ops.append(Call->op_begin() + 2, e); + +  // Push live variables for the stack map. +  addStackMapLiveVars(CS, NumMetaOpers + NumArgs, dl, Ops, *this); + +  // Push the register mask info. +  if (HasGlue) +    Ops.push_back(*(Call->op_end()-2)); +  else +    Ops.push_back(*(Call->op_end()-1)); + +  // Push the chain (this is originally the first operand of the call, but +  // becomes now the last or second to last operand). +  Ops.push_back(*(Call->op_begin())); + +  // Push the glue flag (last operand). +  if (HasGlue) +    Ops.push_back(*(Call->op_end()-1)); + +  SDVTList NodeTys; +  if (IsAnyRegCC && HasDef) { +    // Create the return types based on the intrinsic definition +    const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +    SmallVector<EVT, 3> ValueVTs; +    ComputeValueVTs(TLI, DAG.getDataLayout(), CS->getType(), ValueVTs); +    assert(ValueVTs.size() == 1 && "Expected only one return value type."); + +    // There is always a chain and a glue type at the end +    ValueVTs.push_back(MVT::Other); +    ValueVTs.push_back(MVT::Glue); +    NodeTys = DAG.getVTList(ValueVTs); +  } else +    NodeTys = DAG.getVTList(MVT::Other, MVT::Glue); + +  // Replace the target specific call node with a PATCHPOINT node. +  MachineSDNode *MN = DAG.getMachineNode(TargetOpcode::PATCHPOINT, +                                         dl, NodeTys, Ops); + +  // Update the NodeMap. +  if (HasDef) { +    if (IsAnyRegCC) +      setValue(CS.getInstruction(), SDValue(MN, 0)); +    else +      setValue(CS.getInstruction(), Result.first); +  } + +  // Fixup the consumers of the intrinsic. The chain and glue may be used in the +  // call sequence. Furthermore the location of the chain and glue can change +  // when the AnyReg calling convention is used and the intrinsic returns a +  // value. +  if (IsAnyRegCC && HasDef) { +    SDValue From[] = {SDValue(Call, 0), SDValue(Call, 1)}; +    SDValue To[] = {SDValue(MN, 1), SDValue(MN, 2)}; +    DAG.ReplaceAllUsesOfValuesWith(From, To, 2); +  } else +    DAG.ReplaceAllUsesWith(Call, MN); +  DAG.DeleteNode(Call); + +  // Inform the Frame Information that we have a patchpoint in this function. +  FuncInfo.MF->getFrameInfo().setHasPatchPoint(); +} + +void SelectionDAGBuilder::visitVectorReduce(const CallInst &I, +                                            unsigned Intrinsic) { +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  SDValue Op1 = getValue(I.getArgOperand(0)); +  SDValue Op2; +  if (I.getNumArgOperands() > 1) +    Op2 = getValue(I.getArgOperand(1)); +  SDLoc dl = getCurSDLoc(); +  EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType()); +  SDValue Res; +  FastMathFlags FMF; +  if (isa<FPMathOperator>(I)) +    FMF = I.getFastMathFlags(); +  SDNodeFlags SDFlags; +  SDFlags.setNoNaNs(FMF.noNaNs()); + +  switch (Intrinsic) { +  case Intrinsic::experimental_vector_reduce_fadd: +    if (FMF.unsafeAlgebra()) +      Res = DAG.getNode(ISD::VECREDUCE_FADD, dl, VT, Op2); +    else +      Res = DAG.getNode(ISD::VECREDUCE_STRICT_FADD, dl, VT, Op1, Op2); +    break; +  case Intrinsic::experimental_vector_reduce_fmul: +    if (FMF.unsafeAlgebra()) +      Res = DAG.getNode(ISD::VECREDUCE_FMUL, dl, VT, Op2); +    else +      Res = DAG.getNode(ISD::VECREDUCE_STRICT_FMUL, dl, VT, Op1, Op2); +    break; +  case Intrinsic::experimental_vector_reduce_add: +    Res = DAG.getNode(ISD::VECREDUCE_ADD, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_mul: +    Res = DAG.getNode(ISD::VECREDUCE_MUL, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_and: +    Res = DAG.getNode(ISD::VECREDUCE_AND, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_or: +    Res = DAG.getNode(ISD::VECREDUCE_OR, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_xor: +    Res = DAG.getNode(ISD::VECREDUCE_XOR, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_smax: +    Res = DAG.getNode(ISD::VECREDUCE_SMAX, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_smin: +    Res = DAG.getNode(ISD::VECREDUCE_SMIN, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_umax: +    Res = DAG.getNode(ISD::VECREDUCE_UMAX, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_umin: +    Res = DAG.getNode(ISD::VECREDUCE_UMIN, dl, VT, Op1); +    break; +  case Intrinsic::experimental_vector_reduce_fmax: { +    Res = DAG.getNode(ISD::VECREDUCE_FMAX, dl, VT, Op1, SDFlags); +    break; +  } +  case Intrinsic::experimental_vector_reduce_fmin: { +    Res = DAG.getNode(ISD::VECREDUCE_FMIN, dl, VT, Op1, SDFlags); +    break; +  } +  default: +    llvm_unreachable("Unhandled vector reduce intrinsic"); +  } +  setValue(&I, Res); +} + +/// Returns an AttributeList representing the attributes applied to the return +/// value of the given call. +static AttributeList getReturnAttrs(TargetLowering::CallLoweringInfo &CLI) { +  SmallVector<Attribute::AttrKind, 2> Attrs; +  if (CLI.RetSExt) +    Attrs.push_back(Attribute::SExt); +  if (CLI.RetZExt) +    Attrs.push_back(Attribute::ZExt); +  if (CLI.IsInReg) +    Attrs.push_back(Attribute::InReg); + +  return AttributeList::get(CLI.RetTy->getContext(), AttributeList::ReturnIndex, +                            Attrs); +} + +/// TargetLowering::LowerCallTo - This is the default LowerCallTo +/// implementation, which just calls LowerCall. +/// FIXME: When all targets are +/// migrated to using LowerCall, this hook should be integrated into SDISel. +std::pair<SDValue, SDValue> +TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const { +  // Handle the incoming return values from the call. +  CLI.Ins.clear(); +  Type *OrigRetTy = CLI.RetTy; +  SmallVector<EVT, 4> RetTys; +  SmallVector<uint64_t, 4> Offsets; +  auto &DL = CLI.DAG.getDataLayout(); +  ComputeValueVTs(*this, DL, CLI.RetTy, RetTys, &Offsets); + +  SmallVector<ISD::OutputArg, 4> Outs; +  GetReturnInfo(CLI.RetTy, getReturnAttrs(CLI), Outs, *this, DL); + +  bool CanLowerReturn = +      this->CanLowerReturn(CLI.CallConv, CLI.DAG.getMachineFunction(), +                           CLI.IsVarArg, Outs, CLI.RetTy->getContext()); + +  SDValue DemoteStackSlot; +  int DemoteStackIdx = -100; +  if (!CanLowerReturn) { +    // FIXME: equivalent assert? +    // assert(!CS.hasInAllocaArgument() && +    //        "sret demotion is incompatible with inalloca"); +    uint64_t TySize = DL.getTypeAllocSize(CLI.RetTy); +    unsigned Align = DL.getPrefTypeAlignment(CLI.RetTy); +    MachineFunction &MF = CLI.DAG.getMachineFunction(); +    DemoteStackIdx = MF.getFrameInfo().CreateStackObject(TySize, Align, false); +    Type *StackSlotPtrType = PointerType::getUnqual(CLI.RetTy); + +    DemoteStackSlot = CLI.DAG.getFrameIndex(DemoteStackIdx, getFrameIndexTy(DL)); +    ArgListEntry Entry; +    Entry.Node = DemoteStackSlot; +    Entry.Ty = StackSlotPtrType; +    Entry.IsSExt = false; +    Entry.IsZExt = false; +    Entry.IsInReg = false; +    Entry.IsSRet = true; +    Entry.IsNest = false; +    Entry.IsByVal = false; +    Entry.IsReturned = false; +    Entry.IsSwiftSelf = false; +    Entry.IsSwiftError = false; +    Entry.Alignment = Align; +    CLI.getArgs().insert(CLI.getArgs().begin(), Entry); +    CLI.RetTy = Type::getVoidTy(CLI.RetTy->getContext()); + +    // sret demotion isn't compatible with tail-calls, since the sret argument +    // points into the callers stack frame. +    CLI.IsTailCall = false; +  } else { +    for (unsigned I = 0, E = RetTys.size(); I != E; ++I) { +      EVT VT = RetTys[I]; +      MVT RegisterVT = +          getRegisterTypeForCallingConv(CLI.RetTy->getContext(), VT); +      unsigned NumRegs = +          getNumRegistersForCallingConv(CLI.RetTy->getContext(), VT); +      for (unsigned i = 0; i != NumRegs; ++i) { +        ISD::InputArg MyFlags; +        MyFlags.VT = RegisterVT; +        MyFlags.ArgVT = VT; +        MyFlags.Used = CLI.IsReturnValueUsed; +        if (CLI.RetSExt) +          MyFlags.Flags.setSExt(); +        if (CLI.RetZExt) +          MyFlags.Flags.setZExt(); +        if (CLI.IsInReg) +          MyFlags.Flags.setInReg(); +        CLI.Ins.push_back(MyFlags); +      } +    } +  } + +  // We push in swifterror return as the last element of CLI.Ins. +  ArgListTy &Args = CLI.getArgs(); +  if (supportSwiftError()) { +    for (unsigned i = 0, e = Args.size(); i != e; ++i) { +      if (Args[i].IsSwiftError) { +        ISD::InputArg MyFlags; +        MyFlags.VT = getPointerTy(DL); +        MyFlags.ArgVT = EVT(getPointerTy(DL)); +        MyFlags.Flags.setSwiftError(); +        CLI.Ins.push_back(MyFlags); +      } +    } +  } + +  // Handle all of the outgoing arguments. +  CLI.Outs.clear(); +  CLI.OutVals.clear(); +  for (unsigned i = 0, e = Args.size(); i != e; ++i) { +    SmallVector<EVT, 4> ValueVTs; +    ComputeValueVTs(*this, DL, Args[i].Ty, ValueVTs); +    Type *FinalType = Args[i].Ty; +    if (Args[i].IsByVal) +      FinalType = cast<PointerType>(Args[i].Ty)->getElementType(); +    bool NeedsRegBlock = functionArgumentNeedsConsecutiveRegisters( +        FinalType, CLI.CallConv, CLI.IsVarArg); +    for (unsigned Value = 0, NumValues = ValueVTs.size(); Value != NumValues; +         ++Value) { +      EVT VT = ValueVTs[Value]; +      Type *ArgTy = VT.getTypeForEVT(CLI.RetTy->getContext()); +      SDValue Op = SDValue(Args[i].Node.getNode(), +                           Args[i].Node.getResNo() + Value); +      ISD::ArgFlagsTy Flags; + +      // Certain targets (such as MIPS), may have a different ABI alignment +      // for a type depending on the context. Give the target a chance to +      // specify the alignment it wants. +      unsigned OriginalAlignment = getABIAlignmentForCallingConv(ArgTy, DL); + +      if (Args[i].IsZExt) +        Flags.setZExt(); +      if (Args[i].IsSExt) +        Flags.setSExt(); +      if (Args[i].IsInReg) { +        // If we are using vectorcall calling convention, a structure that is +        // passed InReg - is surely an HVA +        if (CLI.CallConv == CallingConv::X86_VectorCall && +            isa<StructType>(FinalType)) { +          // The first value of a structure is marked +          if (0 == Value) +            Flags.setHvaStart(); +          Flags.setHva(); +        } +        // Set InReg Flag +        Flags.setInReg(); +      } +      if (Args[i].IsSRet) +        Flags.setSRet(); +      if (Args[i].IsSwiftSelf) +        Flags.setSwiftSelf(); +      if (Args[i].IsSwiftError) +        Flags.setSwiftError(); +      if (Args[i].IsByVal) +        Flags.setByVal(); +      if (Args[i].IsInAlloca) { +        Flags.setInAlloca(); +        // Set the byval flag for CCAssignFn callbacks that don't know about +        // inalloca.  This way we can know how many bytes we should've allocated +        // and how many bytes a callee cleanup function will pop.  If we port +        // inalloca to more targets, we'll have to add custom inalloca handling +        // in the various CC lowering callbacks. +        Flags.setByVal(); +      } +      if (Args[i].IsByVal || Args[i].IsInAlloca) { +        PointerType *Ty = cast<PointerType>(Args[i].Ty); +        Type *ElementTy = Ty->getElementType(); +        Flags.setByValSize(DL.getTypeAllocSize(ElementTy)); +        // For ByVal, alignment should come from FE.  BE will guess if this +        // info is not there but there are cases it cannot get right. +        unsigned FrameAlign; +        if (Args[i].Alignment) +          FrameAlign = Args[i].Alignment; +        else +          FrameAlign = getByValTypeAlignment(ElementTy, DL); +        Flags.setByValAlign(FrameAlign); +      } +      if (Args[i].IsNest) +        Flags.setNest(); +      if (NeedsRegBlock) +        Flags.setInConsecutiveRegs(); +      Flags.setOrigAlign(OriginalAlignment); + +      MVT PartVT = getRegisterTypeForCallingConv(CLI.RetTy->getContext(), VT); +      unsigned NumParts = +          getNumRegistersForCallingConv(CLI.RetTy->getContext(), VT); +      SmallVector<SDValue, 4> Parts(NumParts); +      ISD::NodeType ExtendKind = ISD::ANY_EXTEND; + +      if (Args[i].IsSExt) +        ExtendKind = ISD::SIGN_EXTEND; +      else if (Args[i].IsZExt) +        ExtendKind = ISD::ZERO_EXTEND; + +      // Conservatively only handle 'returned' on non-vectors for now +      if (Args[i].IsReturned && !Op.getValueType().isVector()) { +        assert(CLI.RetTy == Args[i].Ty && RetTys.size() == NumValues && +               "unexpected use of 'returned'"); +        // Before passing 'returned' to the target lowering code, ensure that +        // either the register MVT and the actual EVT are the same size or that +        // the return value and argument are extended in the same way; in these +        // cases it's safe to pass the argument register value unchanged as the +        // return register value (although it's at the target's option whether +        // to do so) +        // TODO: allow code generation to take advantage of partially preserved +        // registers rather than clobbering the entire register when the +        // parameter extension method is not compatible with the return +        // extension method +        if ((NumParts * PartVT.getSizeInBits() == VT.getSizeInBits()) || +            (ExtendKind != ISD::ANY_EXTEND && CLI.RetSExt == Args[i].IsSExt && +             CLI.RetZExt == Args[i].IsZExt)) +          Flags.setReturned(); +      } + +      getCopyToParts(CLI.DAG, CLI.DL, Op, &Parts[0], NumParts, PartVT, +                     CLI.CS ? CLI.CS->getInstruction() : nullptr, ExtendKind, +                     true); + +      for (unsigned j = 0; j != NumParts; ++j) { +        // if it isn't first piece, alignment must be 1 +        ISD::OutputArg MyFlags(Flags, Parts[j].getValueType(), VT, +                               i < CLI.NumFixedArgs, +                               i, j*Parts[j].getValueType().getStoreSize()); +        if (NumParts > 1 && j == 0) +          MyFlags.Flags.setSplit(); +        else if (j != 0) { +          MyFlags.Flags.setOrigAlign(1); +          if (j == NumParts - 1) +            MyFlags.Flags.setSplitEnd(); +        } + +        CLI.Outs.push_back(MyFlags); +        CLI.OutVals.push_back(Parts[j]); +      } + +      if (NeedsRegBlock && Value == NumValues - 1) +        CLI.Outs[CLI.Outs.size() - 1].Flags.setInConsecutiveRegsLast(); +    } +  } + +  SmallVector<SDValue, 4> InVals; +  CLI.Chain = LowerCall(CLI, InVals); + +  // Update CLI.InVals to use outside of this function. +  CLI.InVals = InVals; + +  // Verify that the target's LowerCall behaved as expected. +  assert(CLI.Chain.getNode() && CLI.Chain.getValueType() == MVT::Other && +         "LowerCall didn't return a valid chain!"); +  assert((!CLI.IsTailCall || InVals.empty()) && +         "LowerCall emitted a return value for a tail call!"); +  assert((CLI.IsTailCall || InVals.size() == CLI.Ins.size()) && +         "LowerCall didn't emit the correct number of values!"); + +  // For a tail call, the return value is merely live-out and there aren't +  // any nodes in the DAG representing it. Return a special value to +  // indicate that a tail call has been emitted and no more Instructions +  // should be processed in the current block. +  if (CLI.IsTailCall) { +    CLI.DAG.setRoot(CLI.Chain); +    return std::make_pair(SDValue(), SDValue()); +  } + +#ifndef NDEBUG +  for (unsigned i = 0, e = CLI.Ins.size(); i != e; ++i) { +    assert(InVals[i].getNode() && "LowerCall emitted a null value!"); +    assert(EVT(CLI.Ins[i].VT) == InVals[i].getValueType() && +           "LowerCall emitted a value with the wrong type!"); +  } +#endif + +  SmallVector<SDValue, 4> ReturnValues; +  if (!CanLowerReturn) { +    // The instruction result is the result of loading from the +    // hidden sret parameter. +    SmallVector<EVT, 1> PVTs; +    Type *PtrRetTy = PointerType::getUnqual(OrigRetTy); + +    ComputeValueVTs(*this, DL, PtrRetTy, PVTs); +    assert(PVTs.size() == 1 && "Pointers should fit in one register"); +    EVT PtrVT = PVTs[0]; + +    unsigned NumValues = RetTys.size(); +    ReturnValues.resize(NumValues); +    SmallVector<SDValue, 4> Chains(NumValues); + +    // An aggregate return value cannot wrap around the address space, so +    // offsets to its parts don't wrap either. +    SDNodeFlags Flags; +    Flags.setNoUnsignedWrap(true); + +    for (unsigned i = 0; i < NumValues; ++i) { +      SDValue Add = CLI.DAG.getNode(ISD::ADD, CLI.DL, PtrVT, DemoteStackSlot, +                                    CLI.DAG.getConstant(Offsets[i], CLI.DL, +                                                        PtrVT), Flags); +      SDValue L = CLI.DAG.getLoad( +          RetTys[i], CLI.DL, CLI.Chain, Add, +          MachinePointerInfo::getFixedStack(CLI.DAG.getMachineFunction(), +                                            DemoteStackIdx, Offsets[i]), +          /* Alignment = */ 1); +      ReturnValues[i] = L; +      Chains[i] = L.getValue(1); +    } + +    CLI.Chain = CLI.DAG.getNode(ISD::TokenFactor, CLI.DL, MVT::Other, Chains); +  } else { +    // Collect the legal value parts into potentially illegal values +    // that correspond to the original function's return values. +    Optional<ISD::NodeType> AssertOp; +    if (CLI.RetSExt) +      AssertOp = ISD::AssertSext; +    else if (CLI.RetZExt) +      AssertOp = ISD::AssertZext; +    unsigned CurReg = 0; +    for (unsigned I = 0, E = RetTys.size(); I != E; ++I) { +      EVT VT = RetTys[I]; +      MVT RegisterVT = +          getRegisterTypeForCallingConv(CLI.RetTy->getContext(), VT); +      unsigned NumRegs = +          getNumRegistersForCallingConv(CLI.RetTy->getContext(), VT); + +      ReturnValues.push_back(getCopyFromParts(CLI.DAG, CLI.DL, &InVals[CurReg], +                                              NumRegs, RegisterVT, VT, nullptr, +                                              AssertOp, true)); +      CurReg += NumRegs; +    } + +    // For a function returning void, there is no return value. We can't create +    // such a node, so we just return a null return value in that case. In +    // that case, nothing will actually look at the value. +    if (ReturnValues.empty()) +      return std::make_pair(SDValue(), CLI.Chain); +  } + +  SDValue Res = CLI.DAG.getNode(ISD::MERGE_VALUES, CLI.DL, +                                CLI.DAG.getVTList(RetTys), ReturnValues); +  return std::make_pair(Res, CLI.Chain); +} + +void TargetLowering::LowerOperationWrapper(SDNode *N, +                                           SmallVectorImpl<SDValue> &Results, +                                           SelectionDAG &DAG) const { +  if (SDValue Res = LowerOperation(SDValue(N, 0), DAG)) +    Results.push_back(Res); +} + +SDValue TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { +  llvm_unreachable("LowerOperation not implemented for this target!"); +} + +void +SelectionDAGBuilder::CopyValueToVirtualRegister(const Value *V, unsigned Reg) { +  SDValue Op = getNonRegisterValue(V); +  assert((Op.getOpcode() != ISD::CopyFromReg || +          cast<RegisterSDNode>(Op.getOperand(1))->getReg() != Reg) && +         "Copy from a reg to the same reg!"); +  assert(!TargetRegisterInfo::isPhysicalRegister(Reg) && "Is a physreg"); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  // If this is an InlineAsm we have to match the registers required, not the +  // notional registers required by the type. +  bool IsABIRegCopy = +    V && ((isa<CallInst>(V) && +           !(static_cast<const CallInst *>(V))->isInlineAsm()) || +          isa<ReturnInst>(V)); + +  RegsForValue RFV(V->getContext(), TLI, DAG.getDataLayout(), Reg, +                   V->getType(), IsABIRegCopy); +  SDValue Chain = DAG.getEntryNode(); + +  ISD::NodeType ExtendType = (FuncInfo.PreferredExtendType.find(V) == +                              FuncInfo.PreferredExtendType.end()) +                                 ? ISD::ANY_EXTEND +                                 : FuncInfo.PreferredExtendType[V]; +  RFV.getCopyToRegs(Op, DAG, getCurSDLoc(), Chain, nullptr, V, ExtendType); +  PendingExports.push_back(Chain); +} + +#include "llvm/CodeGen/SelectionDAGISel.h" + +/// isOnlyUsedInEntryBlock - If the specified argument is only used in the +/// entry block, return true.  This includes arguments used by switches, since +/// the switch may expand into multiple basic blocks. +static bool isOnlyUsedInEntryBlock(const Argument *A, bool FastISel) { +  // With FastISel active, we may be splitting blocks, so force creation +  // of virtual registers for all non-dead arguments. +  if (FastISel) +    return A->use_empty(); + +  const BasicBlock &Entry = A->getParent()->front(); +  for (const User *U : A->users()) +    if (cast<Instruction>(U)->getParent() != &Entry || isa<SwitchInst>(U)) +      return false;  // Use not in entry block. + +  return true; +} + +typedef DenseMap<const Argument *, +                 std::pair<const AllocaInst *, const StoreInst *>> +    ArgCopyElisionMapTy; + +/// Scan the entry block of the function in FuncInfo for arguments that look +/// like copies into a local alloca. Record any copied arguments in +/// ArgCopyElisionCandidates. +static void +findArgumentCopyElisionCandidates(const DataLayout &DL, +                                  FunctionLoweringInfo *FuncInfo, +                                  ArgCopyElisionMapTy &ArgCopyElisionCandidates) { +  // Record the state of every static alloca used in the entry block. Argument +  // allocas are all used in the entry block, so we need approximately as many +  // entries as we have arguments. +  enum StaticAllocaInfo { Unknown, Clobbered, Elidable }; +  SmallDenseMap<const AllocaInst *, StaticAllocaInfo, 8> StaticAllocas; +  unsigned NumArgs = FuncInfo->Fn->arg_size(); +  StaticAllocas.reserve(NumArgs * 2); + +  auto GetInfoIfStaticAlloca = [&](const Value *V) -> StaticAllocaInfo * { +    if (!V) +      return nullptr; +    V = V->stripPointerCasts(); +    const auto *AI = dyn_cast<AllocaInst>(V); +    if (!AI || !AI->isStaticAlloca() || !FuncInfo->StaticAllocaMap.count(AI)) +      return nullptr; +    auto Iter = StaticAllocas.insert({AI, Unknown}); +    return &Iter.first->second; +  }; + +  // Look for stores of arguments to static allocas. Look through bitcasts and +  // GEPs to handle type coercions, as long as the alloca is fully initialized +  // by the store. Any non-store use of an alloca escapes it and any subsequent +  // unanalyzed store might write it. +  // FIXME: Handle structs initialized with multiple stores. +  for (const Instruction &I : FuncInfo->Fn->getEntryBlock()) { +    // Look for stores, and handle non-store uses conservatively. +    const auto *SI = dyn_cast<StoreInst>(&I); +    if (!SI) { +      // We will look through cast uses, so ignore them completely. +      if (I.isCast()) +        continue; +      // Ignore debug info intrinsics, they don't escape or store to allocas. +      if (isa<DbgInfoIntrinsic>(I)) +        continue; +      // This is an unknown instruction. Assume it escapes or writes to all +      // static alloca operands. +      for (const Use &U : I.operands()) { +        if (StaticAllocaInfo *Info = GetInfoIfStaticAlloca(U)) +          *Info = StaticAllocaInfo::Clobbered; +      } +      continue; +    } + +    // If the stored value is a static alloca, mark it as escaped. +    if (StaticAllocaInfo *Info = GetInfoIfStaticAlloca(SI->getValueOperand())) +      *Info = StaticAllocaInfo::Clobbered; + +    // Check if the destination is a static alloca. +    const Value *Dst = SI->getPointerOperand()->stripPointerCasts(); +    StaticAllocaInfo *Info = GetInfoIfStaticAlloca(Dst); +    if (!Info) +      continue; +    const AllocaInst *AI = cast<AllocaInst>(Dst); + +    // Skip allocas that have been initialized or clobbered. +    if (*Info != StaticAllocaInfo::Unknown) +      continue; + +    // Check if the stored value is an argument, and that this store fully +    // initializes the alloca. Don't elide copies from the same argument twice. +    const Value *Val = SI->getValueOperand()->stripPointerCasts(); +    const auto *Arg = dyn_cast<Argument>(Val); +    if (!Arg || Arg->hasInAllocaAttr() || Arg->hasByValAttr() || +        Arg->getType()->isEmptyTy() || +        DL.getTypeStoreSize(Arg->getType()) != +            DL.getTypeAllocSize(AI->getAllocatedType()) || +        ArgCopyElisionCandidates.count(Arg)) { +      *Info = StaticAllocaInfo::Clobbered; +      continue; +    } + +    DEBUG(dbgs() << "Found argument copy elision candidate: " << *AI << '\n'); + +    // Mark this alloca and store for argument copy elision. +    *Info = StaticAllocaInfo::Elidable; +    ArgCopyElisionCandidates.insert({Arg, {AI, SI}}); + +    // Stop scanning if we've seen all arguments. This will happen early in -O0 +    // builds, which is useful, because -O0 builds have large entry blocks and +    // many allocas. +    if (ArgCopyElisionCandidates.size() == NumArgs) +      break; +  } +} + +/// Try to elide argument copies from memory into a local alloca. Succeeds if +/// ArgVal is a load from a suitable fixed stack object. +static void tryToElideArgumentCopy( +    FunctionLoweringInfo *FuncInfo, SmallVectorImpl<SDValue> &Chains, +    DenseMap<int, int> &ArgCopyElisionFrameIndexMap, +    SmallPtrSetImpl<const Instruction *> &ElidedArgCopyInstrs, +    ArgCopyElisionMapTy &ArgCopyElisionCandidates, const Argument &Arg, +    SDValue ArgVal, bool &ArgHasUses) { +  // Check if this is a load from a fixed stack object. +  auto *LNode = dyn_cast<LoadSDNode>(ArgVal); +  if (!LNode) +    return; +  auto *FINode = dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()); +  if (!FINode) +    return; + +  // Check that the fixed stack object is the right size and alignment. +  // Look at the alignment that the user wrote on the alloca instead of looking +  // at the stack object. +  auto ArgCopyIter = ArgCopyElisionCandidates.find(&Arg); +  assert(ArgCopyIter != ArgCopyElisionCandidates.end()); +  const AllocaInst *AI = ArgCopyIter->second.first; +  int FixedIndex = FINode->getIndex(); +  int &AllocaIndex = FuncInfo->StaticAllocaMap[AI]; +  int OldIndex = AllocaIndex; +  MachineFrameInfo &MFI = FuncInfo->MF->getFrameInfo(); +  if (MFI.getObjectSize(FixedIndex) != MFI.getObjectSize(OldIndex)) { +    DEBUG(dbgs() << "  argument copy elision failed due to bad fixed stack " +                    "object size\n"); +    return; +  } +  unsigned RequiredAlignment = AI->getAlignment(); +  if (!RequiredAlignment) { +    RequiredAlignment = FuncInfo->MF->getDataLayout().getABITypeAlignment( +        AI->getAllocatedType()); +  } +  if (MFI.getObjectAlignment(FixedIndex) < RequiredAlignment) { +    DEBUG(dbgs() << "  argument copy elision failed: alignment of alloca " +                    "greater than stack argument alignment (" +                 << RequiredAlignment << " vs " +                 << MFI.getObjectAlignment(FixedIndex) << ")\n"); +    return; +  } + +  // Perform the elision. Delete the old stack object and replace its only use +  // in the variable info map. Mark the stack object as mutable. +  DEBUG({ +    dbgs() << "Eliding argument copy from " << Arg << " to " << *AI << '\n' +           << "  Replacing frame index " << OldIndex << " with " << FixedIndex +           << '\n'; +  }); +  MFI.RemoveStackObject(OldIndex); +  MFI.setIsImmutableObjectIndex(FixedIndex, false); +  AllocaIndex = FixedIndex; +  ArgCopyElisionFrameIndexMap.insert({OldIndex, FixedIndex}); +  Chains.push_back(ArgVal.getValue(1)); + +  // Avoid emitting code for the store implementing the copy. +  const StoreInst *SI = ArgCopyIter->second.second; +  ElidedArgCopyInstrs.insert(SI); + +  // Check for uses of the argument again so that we can avoid exporting ArgVal +  // if it is't used by anything other than the store. +  for (const Value *U : Arg.users()) { +    if (U != SI) { +      ArgHasUses = true; +      break; +    } +  } +} + +void SelectionDAGISel::LowerArguments(const Function &F) { +  SelectionDAG &DAG = SDB->DAG; +  SDLoc dl = SDB->getCurSDLoc(); +  const DataLayout &DL = DAG.getDataLayout(); +  SmallVector<ISD::InputArg, 16> Ins; + +  if (!FuncInfo->CanLowerReturn) { +    // Put in an sret pointer parameter before all the other parameters. +    SmallVector<EVT, 1> ValueVTs; +    ComputeValueVTs(*TLI, DAG.getDataLayout(), +                    PointerType::getUnqual(F.getReturnType()), ValueVTs); + +    // NOTE: Assuming that a pointer will never break down to more than one VT +    // or one register. +    ISD::ArgFlagsTy Flags; +    Flags.setSRet(); +    MVT RegisterVT = TLI->getRegisterType(*DAG.getContext(), ValueVTs[0]); +    ISD::InputArg RetArg(Flags, RegisterVT, ValueVTs[0], true, +                         ISD::InputArg::NoArgIndex, 0); +    Ins.push_back(RetArg); +  } + +  // Look for stores of arguments to static allocas. Mark such arguments with a +  // flag to ask the target to give us the memory location of that argument if +  // available. +  ArgCopyElisionMapTy ArgCopyElisionCandidates; +  findArgumentCopyElisionCandidates(DL, FuncInfo, ArgCopyElisionCandidates); + +  // Set up the incoming argument description vector. +  for (const Argument &Arg : F.args()) { +    unsigned ArgNo = Arg.getArgNo(); +    SmallVector<EVT, 4> ValueVTs; +    ComputeValueVTs(*TLI, DAG.getDataLayout(), Arg.getType(), ValueVTs); +    bool isArgValueUsed = !Arg.use_empty(); +    unsigned PartBase = 0; +    Type *FinalType = Arg.getType(); +    if (Arg.hasAttribute(Attribute::ByVal)) +      FinalType = cast<PointerType>(FinalType)->getElementType(); +    bool NeedsRegBlock = TLI->functionArgumentNeedsConsecutiveRegisters( +        FinalType, F.getCallingConv(), F.isVarArg()); +    for (unsigned Value = 0, NumValues = ValueVTs.size(); +         Value != NumValues; ++Value) { +      EVT VT = ValueVTs[Value]; +      Type *ArgTy = VT.getTypeForEVT(*DAG.getContext()); +      ISD::ArgFlagsTy Flags; + +      // Certain targets (such as MIPS), may have a different ABI alignment +      // for a type depending on the context. Give the target a chance to +      // specify the alignment it wants. +      unsigned OriginalAlignment = +          TLI->getABIAlignmentForCallingConv(ArgTy, DL); + +      if (Arg.hasAttribute(Attribute::ZExt)) +        Flags.setZExt(); +      if (Arg.hasAttribute(Attribute::SExt)) +        Flags.setSExt(); +      if (Arg.hasAttribute(Attribute::InReg)) { +        // If we are using vectorcall calling convention, a structure that is +        // passed InReg - is surely an HVA +        if (F.getCallingConv() == CallingConv::X86_VectorCall && +            isa<StructType>(Arg.getType())) { +          // The first value of a structure is marked +          if (0 == Value) +            Flags.setHvaStart(); +          Flags.setHva(); +        } +        // Set InReg Flag +        Flags.setInReg(); +      } +      if (Arg.hasAttribute(Attribute::StructRet)) +        Flags.setSRet(); +      if (Arg.hasAttribute(Attribute::SwiftSelf)) +        Flags.setSwiftSelf(); +      if (Arg.hasAttribute(Attribute::SwiftError)) +        Flags.setSwiftError(); +      if (Arg.hasAttribute(Attribute::ByVal)) +        Flags.setByVal(); +      if (Arg.hasAttribute(Attribute::InAlloca)) { +        Flags.setInAlloca(); +        // Set the byval flag for CCAssignFn callbacks that don't know about +        // inalloca.  This way we can know how many bytes we should've allocated +        // and how many bytes a callee cleanup function will pop.  If we port +        // inalloca to more targets, we'll have to add custom inalloca handling +        // in the various CC lowering callbacks. +        Flags.setByVal(); +      } +      if (F.getCallingConv() == CallingConv::X86_INTR) { +        // IA Interrupt passes frame (1st parameter) by value in the stack. +        if (ArgNo == 0) +          Flags.setByVal(); +      } +      if (Flags.isByVal() || Flags.isInAlloca()) { +        PointerType *Ty = cast<PointerType>(Arg.getType()); +        Type *ElementTy = Ty->getElementType(); +        Flags.setByValSize(DL.getTypeAllocSize(ElementTy)); +        // For ByVal, alignment should be passed from FE.  BE will guess if +        // this info is not there but there are cases it cannot get right. +        unsigned FrameAlign; +        if (Arg.getParamAlignment()) +          FrameAlign = Arg.getParamAlignment(); +        else +          FrameAlign = TLI->getByValTypeAlignment(ElementTy, DL); +        Flags.setByValAlign(FrameAlign); +      } +      if (Arg.hasAttribute(Attribute::Nest)) +        Flags.setNest(); +      if (NeedsRegBlock) +        Flags.setInConsecutiveRegs(); +      Flags.setOrigAlign(OriginalAlignment); +      if (ArgCopyElisionCandidates.count(&Arg)) +        Flags.setCopyElisionCandidate(); + +      MVT RegisterVT = +          TLI->getRegisterTypeForCallingConv(*CurDAG->getContext(), VT); +      unsigned NumRegs = +          TLI->getNumRegistersForCallingConv(*CurDAG->getContext(), VT); +      for (unsigned i = 0; i != NumRegs; ++i) { +        ISD::InputArg MyFlags(Flags, RegisterVT, VT, isArgValueUsed, +                              ArgNo, PartBase+i*RegisterVT.getStoreSize()); +        if (NumRegs > 1 && i == 0) +          MyFlags.Flags.setSplit(); +        // if it isn't first piece, alignment must be 1 +        else if (i > 0) { +          MyFlags.Flags.setOrigAlign(1); +          if (i == NumRegs - 1) +            MyFlags.Flags.setSplitEnd(); +        } +        Ins.push_back(MyFlags); +      } +      if (NeedsRegBlock && Value == NumValues - 1) +        Ins[Ins.size() - 1].Flags.setInConsecutiveRegsLast(); +      PartBase += VT.getStoreSize(); +    } +  } + +  // Call the target to set up the argument values. +  SmallVector<SDValue, 8> InVals; +  SDValue NewRoot = TLI->LowerFormalArguments( +      DAG.getRoot(), F.getCallingConv(), F.isVarArg(), Ins, dl, DAG, InVals); + +  // Verify that the target's LowerFormalArguments behaved as expected. +  assert(NewRoot.getNode() && NewRoot.getValueType() == MVT::Other && +         "LowerFormalArguments didn't return a valid chain!"); +  assert(InVals.size() == Ins.size() && +         "LowerFormalArguments didn't emit the correct number of values!"); +  DEBUG({ +      for (unsigned i = 0, e = Ins.size(); i != e; ++i) { +        assert(InVals[i].getNode() && +               "LowerFormalArguments emitted a null value!"); +        assert(EVT(Ins[i].VT) == InVals[i].getValueType() && +               "LowerFormalArguments emitted a value with the wrong type!"); +      } +    }); + +  // Update the DAG with the new chain value resulting from argument lowering. +  DAG.setRoot(NewRoot); + +  // Set up the argument values. +  unsigned i = 0; +  if (!FuncInfo->CanLowerReturn) { +    // Create a virtual register for the sret pointer, and put in a copy +    // from the sret argument into it. +    SmallVector<EVT, 1> ValueVTs; +    ComputeValueVTs(*TLI, DAG.getDataLayout(), +                    PointerType::getUnqual(F.getReturnType()), ValueVTs); +    MVT VT = ValueVTs[0].getSimpleVT(); +    MVT RegVT = TLI->getRegisterType(*CurDAG->getContext(), VT); +    Optional<ISD::NodeType> AssertOp = None; +    SDValue ArgValue = getCopyFromParts(DAG, dl, &InVals[0], 1, +                                        RegVT, VT, nullptr, AssertOp); + +    MachineFunction& MF = SDB->DAG.getMachineFunction(); +    MachineRegisterInfo& RegInfo = MF.getRegInfo(); +    unsigned SRetReg = RegInfo.createVirtualRegister(TLI->getRegClassFor(RegVT)); +    FuncInfo->DemoteRegister = SRetReg; +    NewRoot = +        SDB->DAG.getCopyToReg(NewRoot, SDB->getCurSDLoc(), SRetReg, ArgValue); +    DAG.setRoot(NewRoot); + +    // i indexes lowered arguments.  Bump it past the hidden sret argument. +    ++i; +  } + +  SmallVector<SDValue, 4> Chains; +  DenseMap<int, int> ArgCopyElisionFrameIndexMap; +  for (const Argument &Arg : F.args()) { +    SmallVector<SDValue, 4> ArgValues; +    SmallVector<EVT, 4> ValueVTs; +    ComputeValueVTs(*TLI, DAG.getDataLayout(), Arg.getType(), ValueVTs); +    unsigned NumValues = ValueVTs.size(); +    if (NumValues == 0) +      continue; + +    bool ArgHasUses = !Arg.use_empty(); + +    // Elide the copying store if the target loaded this argument from a +    // suitable fixed stack object. +    if (Ins[i].Flags.isCopyElisionCandidate()) { +      tryToElideArgumentCopy(FuncInfo, Chains, ArgCopyElisionFrameIndexMap, +                             ElidedArgCopyInstrs, ArgCopyElisionCandidates, Arg, +                             InVals[i], ArgHasUses); +    } + +    // If this argument is unused then remember its value. It is used to generate +    // debugging information. +    bool isSwiftErrorArg = +        TLI->supportSwiftError() && +        Arg.hasAttribute(Attribute::SwiftError); +    if (!ArgHasUses && !isSwiftErrorArg) { +      SDB->setUnusedArgValue(&Arg, InVals[i]); + +      // Also remember any frame index for use in FastISel. +      if (FrameIndexSDNode *FI = +          dyn_cast<FrameIndexSDNode>(InVals[i].getNode())) +        FuncInfo->setArgumentFrameIndex(&Arg, FI->getIndex()); +    } + +    for (unsigned Val = 0; Val != NumValues; ++Val) { +      EVT VT = ValueVTs[Val]; +      MVT PartVT = +          TLI->getRegisterTypeForCallingConv(*CurDAG->getContext(), VT); +      unsigned NumParts = +          TLI->getNumRegistersForCallingConv(*CurDAG->getContext(), VT); + +      // Even an apparant 'unused' swifterror argument needs to be returned. So +      // we do generate a copy for it that can be used on return from the +      // function. +      if (ArgHasUses || isSwiftErrorArg) { +        Optional<ISD::NodeType> AssertOp; +        if (Arg.hasAttribute(Attribute::SExt)) +          AssertOp = ISD::AssertSext; +        else if (Arg.hasAttribute(Attribute::ZExt)) +          AssertOp = ISD::AssertZext; + +        ArgValues.push_back(getCopyFromParts(DAG, dl, &InVals[i], NumParts, +                                             PartVT, VT, nullptr, AssertOp, +                                             true)); +      } + +      i += NumParts; +    } + +    // We don't need to do anything else for unused arguments. +    if (ArgValues.empty()) +      continue; + +    // Note down frame index. +    if (FrameIndexSDNode *FI = +        dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode())) +      FuncInfo->setArgumentFrameIndex(&Arg, FI->getIndex()); + +    SDValue Res = DAG.getMergeValues(makeArrayRef(ArgValues.data(), NumValues), +                                     SDB->getCurSDLoc()); + +    SDB->setValue(&Arg, Res); +    if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::BUILD_PAIR) { +      if (LoadSDNode *LNode = +          dyn_cast<LoadSDNode>(Res.getOperand(0).getNode())) +        if (FrameIndexSDNode *FI = +            dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode())) +        FuncInfo->setArgumentFrameIndex(&Arg, FI->getIndex()); +    } + +    // Update the SwiftErrorVRegDefMap. +    if (Res.getOpcode() == ISD::CopyFromReg && isSwiftErrorArg) { +      unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg(); +      if (TargetRegisterInfo::isVirtualRegister(Reg)) +        FuncInfo->setCurrentSwiftErrorVReg(FuncInfo->MBB, +                                           FuncInfo->SwiftErrorArg, Reg); +    } + +    // If this argument is live outside of the entry block, insert a copy from +    // wherever we got it to the vreg that other BB's will reference it as. +    if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::CopyFromReg) { +      // If we can, though, try to skip creating an unnecessary vreg. +      // FIXME: This isn't very clean... it would be nice to make this more +      // general.  It's also subtly incompatible with the hacks FastISel +      // uses with vregs. +      unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg(); +      if (TargetRegisterInfo::isVirtualRegister(Reg)) { +        FuncInfo->ValueMap[&Arg] = Reg; +        continue; +      } +    } +    if (!isOnlyUsedInEntryBlock(&Arg, TM.Options.EnableFastISel)) { +      FuncInfo->InitializeRegForValue(&Arg); +      SDB->CopyToExportRegsIfNeeded(&Arg); +    } +  } + +  if (!Chains.empty()) { +    Chains.push_back(NewRoot); +    NewRoot = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Chains); +  } + +  DAG.setRoot(NewRoot); + +  assert(i == InVals.size() && "Argument register count mismatch!"); + +  // If any argument copy elisions occurred and we have debug info, update the +  // stale frame indices used in the dbg.declare variable info table. +  MachineFunction::VariableDbgInfoMapTy &DbgDeclareInfo = MF->getVariableDbgInfo(); +  if (!DbgDeclareInfo.empty() && !ArgCopyElisionFrameIndexMap.empty()) { +    for (MachineFunction::VariableDbgInfo &VI : DbgDeclareInfo) { +      auto I = ArgCopyElisionFrameIndexMap.find(VI.Slot); +      if (I != ArgCopyElisionFrameIndexMap.end()) +        VI.Slot = I->second; +    } +  } + +  // Finally, if the target has anything special to do, allow it to do so. +  EmitFunctionEntryCode(); +} + +/// Handle PHI nodes in successor blocks.  Emit code into the SelectionDAG to +/// ensure constants are generated when needed.  Remember the virtual registers +/// that need to be added to the Machine PHI nodes as input.  We cannot just +/// directly add them, because expansion might result in multiple MBB's for one +/// BB.  As such, the start of the BB might correspond to a different MBB than +/// the end. +/// +void +SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) { +  const TerminatorInst *TI = LLVMBB->getTerminator(); + +  SmallPtrSet<MachineBasicBlock *, 4> SuccsHandled; + +  // Check PHI nodes in successors that expect a value to be available from this +  // block. +  for (unsigned succ = 0, e = TI->getNumSuccessors(); succ != e; ++succ) { +    const BasicBlock *SuccBB = TI->getSuccessor(succ); +    if (!isa<PHINode>(SuccBB->begin())) continue; +    MachineBasicBlock *SuccMBB = FuncInfo.MBBMap[SuccBB]; + +    // If this terminator has multiple identical successors (common for +    // switches), only handle each succ once. +    if (!SuccsHandled.insert(SuccMBB).second) +      continue; + +    MachineBasicBlock::iterator MBBI = SuccMBB->begin(); + +    // At this point we know that there is a 1-1 correspondence between LLVM PHI +    // nodes and Machine PHI nodes, but the incoming operands have not been +    // emitted yet. +    for (BasicBlock::const_iterator I = SuccBB->begin(); +         const PHINode *PN = dyn_cast<PHINode>(I); ++I) { +      // Ignore dead phi's. +      if (PN->use_empty()) continue; + +      // Skip empty types +      if (PN->getType()->isEmptyTy()) +        continue; + +      unsigned Reg; +      const Value *PHIOp = PN->getIncomingValueForBlock(LLVMBB); + +      if (const Constant *C = dyn_cast<Constant>(PHIOp)) { +        unsigned &RegOut = ConstantsOut[C]; +        if (RegOut == 0) { +          RegOut = FuncInfo.CreateRegs(C->getType()); +          CopyValueToVirtualRegister(C, RegOut); +        } +        Reg = RegOut; +      } else { +        DenseMap<const Value *, unsigned>::iterator I = +          FuncInfo.ValueMap.find(PHIOp); +        if (I != FuncInfo.ValueMap.end()) +          Reg = I->second; +        else { +          assert(isa<AllocaInst>(PHIOp) && +                 FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(PHIOp)) && +                 "Didn't codegen value into a register!??"); +          Reg = FuncInfo.CreateRegs(PHIOp->getType()); +          CopyValueToVirtualRegister(PHIOp, Reg); +        } +      } + +      // Remember that this register needs to added to the machine PHI node as +      // the input for this MBB. +      SmallVector<EVT, 4> ValueVTs; +      const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +      ComputeValueVTs(TLI, DAG.getDataLayout(), PN->getType(), ValueVTs); +      for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) { +        EVT VT = ValueVTs[vti]; +        unsigned NumRegisters = TLI.getNumRegisters(*DAG.getContext(), VT); +        for (unsigned i = 0, e = NumRegisters; i != e; ++i) +          FuncInfo.PHINodesToUpdate.push_back( +              std::make_pair(&*MBBI++, Reg + i)); +        Reg += NumRegisters; +      } +    } +  } + +  ConstantsOut.clear(); +} + +/// Add a successor MBB to ParentMBB< creating a new MachineBB for BB if SuccMBB +/// is 0. +MachineBasicBlock * +SelectionDAGBuilder::StackProtectorDescriptor:: +AddSuccessorMBB(const BasicBlock *BB, +                MachineBasicBlock *ParentMBB, +                bool IsLikely, +                MachineBasicBlock *SuccMBB) { +  // If SuccBB has not been created yet, create it. +  if (!SuccMBB) { +    MachineFunction *MF = ParentMBB->getParent(); +    MachineFunction::iterator BBI(ParentMBB); +    SuccMBB = MF->CreateMachineBasicBlock(BB); +    MF->insert(++BBI, SuccMBB); +  } +  // Add it as a successor of ParentMBB. +  ParentMBB->addSuccessor( +      SuccMBB, BranchProbabilityInfo::getBranchProbStackProtector(IsLikely)); +  return SuccMBB; +} + +MachineBasicBlock *SelectionDAGBuilder::NextBlock(MachineBasicBlock *MBB) { +  MachineFunction::iterator I(MBB); +  if (++I == FuncInfo.MF->end()) +    return nullptr; +  return &*I; +} + +/// During lowering new call nodes can be created (such as memset, etc.). +/// Those will become new roots of the current DAG, but complications arise +/// when they are tail calls. In such cases, the call lowering will update +/// the root, but the builder still needs to know that a tail call has been +/// lowered in order to avoid generating an additional return. +void SelectionDAGBuilder::updateDAGForMaybeTailCall(SDValue MaybeTC) { +  // If the node is null, we do have a tail call. +  if (MaybeTC.getNode() != nullptr) +    DAG.setRoot(MaybeTC); +  else +    HasTailCall = true; +} + +uint64_t +SelectionDAGBuilder::getJumpTableRange(const CaseClusterVector &Clusters, +                                       unsigned First, unsigned Last) const { +  assert(Last >= First); +  const APInt &LowCase = Clusters[First].Low->getValue(); +  const APInt &HighCase = Clusters[Last].High->getValue(); +  assert(LowCase.getBitWidth() == HighCase.getBitWidth()); + +  // FIXME: A range of consecutive cases has 100% density, but only requires one +  // comparison to lower. We should discriminate against such consecutive ranges +  // in jump tables. + +  return (HighCase - LowCase).getLimitedValue((UINT64_MAX - 1) / 100) + 1; +} + +uint64_t SelectionDAGBuilder::getJumpTableNumCases( +    const SmallVectorImpl<unsigned> &TotalCases, unsigned First, +    unsigned Last) const { +  assert(Last >= First); +  assert(TotalCases[Last] >= TotalCases[First]); +  uint64_t NumCases = +      TotalCases[Last] - (First == 0 ? 0 : TotalCases[First - 1]); +  return NumCases; +} + +bool SelectionDAGBuilder::buildJumpTable(const CaseClusterVector &Clusters, +                                         unsigned First, unsigned Last, +                                         const SwitchInst *SI, +                                         MachineBasicBlock *DefaultMBB, +                                         CaseCluster &JTCluster) { +  assert(First <= Last); + +  auto Prob = BranchProbability::getZero(); +  unsigned NumCmps = 0; +  std::vector<MachineBasicBlock*> Table; +  DenseMap<MachineBasicBlock*, BranchProbability> JTProbs; + +  // Initialize probabilities in JTProbs. +  for (unsigned I = First; I <= Last; ++I) +    JTProbs[Clusters[I].MBB] = BranchProbability::getZero(); + +  for (unsigned I = First; I <= Last; ++I) { +    assert(Clusters[I].Kind == CC_Range); +    Prob += Clusters[I].Prob; +    const APInt &Low = Clusters[I].Low->getValue(); +    const APInt &High = Clusters[I].High->getValue(); +    NumCmps += (Low == High) ? 1 : 2; +    if (I != First) { +      // Fill the gap between this and the previous cluster. +      const APInt &PreviousHigh = Clusters[I - 1].High->getValue(); +      assert(PreviousHigh.slt(Low)); +      uint64_t Gap = (Low - PreviousHigh).getLimitedValue() - 1; +      for (uint64_t J = 0; J < Gap; J++) +        Table.push_back(DefaultMBB); +    } +    uint64_t ClusterSize = (High - Low).getLimitedValue() + 1; +    for (uint64_t J = 0; J < ClusterSize; ++J) +      Table.push_back(Clusters[I].MBB); +    JTProbs[Clusters[I].MBB] += Clusters[I].Prob; +  } + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  unsigned NumDests = JTProbs.size(); +  if (TLI.isSuitableForBitTests( +          NumDests, NumCmps, Clusters[First].Low->getValue(), +          Clusters[Last].High->getValue(), DAG.getDataLayout())) { +    // Clusters[First..Last] should be lowered as bit tests instead. +    return false; +  } + +  // Create the MBB that will load from and jump through the table. +  // Note: We create it here, but it's not inserted into the function yet. +  MachineFunction *CurMF = FuncInfo.MF; +  MachineBasicBlock *JumpTableMBB = +      CurMF->CreateMachineBasicBlock(SI->getParent()); + +  // Add successors. Note: use table order for determinism. +  SmallPtrSet<MachineBasicBlock *, 8> Done; +  for (MachineBasicBlock *Succ : Table) { +    if (Done.count(Succ)) +      continue; +    addSuccessorWithProb(JumpTableMBB, Succ, JTProbs[Succ]); +    Done.insert(Succ); +  } +  JumpTableMBB->normalizeSuccProbs(); + +  unsigned JTI = CurMF->getOrCreateJumpTableInfo(TLI.getJumpTableEncoding()) +                     ->createJumpTableIndex(Table); + +  // Set up the jump table info. +  JumpTable JT(-1U, JTI, JumpTableMBB, nullptr); +  JumpTableHeader JTH(Clusters[First].Low->getValue(), +                      Clusters[Last].High->getValue(), SI->getCondition(), +                      nullptr, false); +  JTCases.emplace_back(std::move(JTH), std::move(JT)); + +  JTCluster = CaseCluster::jumpTable(Clusters[First].Low, Clusters[Last].High, +                                     JTCases.size() - 1, Prob); +  return true; +} + +void SelectionDAGBuilder::findJumpTables(CaseClusterVector &Clusters, +                                         const SwitchInst *SI, +                                         MachineBasicBlock *DefaultMBB) { +#ifndef NDEBUG +  // Clusters must be non-empty, sorted, and only contain Range clusters. +  assert(!Clusters.empty()); +  for (CaseCluster &C : Clusters) +    assert(C.Kind == CC_Range); +  for (unsigned i = 1, e = Clusters.size(); i < e; ++i) +    assert(Clusters[i - 1].High->getValue().slt(Clusters[i].Low->getValue())); +#endif + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  if (!TLI.areJTsAllowed(SI->getParent()->getParent())) +    return; + +  const int64_t N = Clusters.size(); +  const unsigned MinJumpTableEntries = TLI.getMinimumJumpTableEntries(); +  const unsigned SmallNumberOfEntries = MinJumpTableEntries / 2; + +  if (N < 2 || N < MinJumpTableEntries) +    return; + +  // TotalCases[i]: Total nbr of cases in Clusters[0..i]. +  SmallVector<unsigned, 8> TotalCases(N); +  for (unsigned i = 0; i < N; ++i) { +    const APInt &Hi = Clusters[i].High->getValue(); +    const APInt &Lo = Clusters[i].Low->getValue(); +    TotalCases[i] = (Hi - Lo).getLimitedValue() + 1; +    if (i != 0) +      TotalCases[i] += TotalCases[i - 1]; +  } + +  // Cheap case: the whole range may be suitable for jump table. +  uint64_t Range = getJumpTableRange(Clusters,0, N - 1); +  uint64_t NumCases = getJumpTableNumCases(TotalCases, 0, N - 1); +  assert(NumCases < UINT64_MAX / 100); +  assert(Range >= NumCases); +  if (TLI.isSuitableForJumpTable(SI, NumCases, Range)) { +    CaseCluster JTCluster; +    if (buildJumpTable(Clusters, 0, N - 1, SI, DefaultMBB, JTCluster)) { +      Clusters[0] = JTCluster; +      Clusters.resize(1); +      return; +    } +  } + +  // The algorithm below is not suitable for -O0. +  if (TM.getOptLevel() == CodeGenOpt::None) +    return; + +  // Split Clusters into minimum number of dense partitions. The algorithm uses +  // the same idea as Kannan & Proebsting "Correction to 'Producing Good Code +  // for the Case Statement'" (1994), but builds the MinPartitions array in +  // reverse order to make it easier to reconstruct the partitions in ascending +  // order. In the choice between two optimal partitionings, it picks the one +  // which yields more jump tables. + +  // MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1]. +  SmallVector<unsigned, 8> MinPartitions(N); +  // LastElement[i] is the last element of the partition starting at i. +  SmallVector<unsigned, 8> LastElement(N); +  // PartitionsScore[i] is used to break ties when choosing between two +  // partitionings resulting in the same number of partitions. +  SmallVector<unsigned, 8> PartitionsScore(N); +  // For PartitionsScore, a small number of comparisons is considered as good as +  // a jump table and a single comparison is considered better than a jump +  // table. +  enum PartitionScores : unsigned { +    NoTable = 0, +    Table = 1, +    FewCases = 1, +    SingleCase = 2 +  }; + +  // Base case: There is only one way to partition Clusters[N-1]. +  MinPartitions[N - 1] = 1; +  LastElement[N - 1] = N - 1; +  PartitionsScore[N - 1] = PartitionScores::SingleCase; + +  // Note: loop indexes are signed to avoid underflow. +  for (int64_t i = N - 2; i >= 0; i--) { +    // Find optimal partitioning of Clusters[i..N-1]. +    // Baseline: Put Clusters[i] into a partition on its own. +    MinPartitions[i] = MinPartitions[i + 1] + 1; +    LastElement[i] = i; +    PartitionsScore[i] = PartitionsScore[i + 1] + PartitionScores::SingleCase; + +    // Search for a solution that results in fewer partitions. +    for (int64_t j = N - 1; j > i; j--) { +      // Try building a partition from Clusters[i..j]. +      uint64_t Range = getJumpTableRange(Clusters, i, j); +      uint64_t NumCases = getJumpTableNumCases(TotalCases, i, j); +      assert(NumCases < UINT64_MAX / 100); +      assert(Range >= NumCases); +      if (TLI.isSuitableForJumpTable(SI, NumCases, Range)) { +        unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]); +        unsigned Score = j == N - 1 ? 0 : PartitionsScore[j + 1]; +        int64_t NumEntries = j - i + 1; + +        if (NumEntries == 1) +          Score += PartitionScores::SingleCase; +        else if (NumEntries <= SmallNumberOfEntries) +          Score += PartitionScores::FewCases; +        else if (NumEntries >= MinJumpTableEntries) +          Score += PartitionScores::Table; + +        // If this leads to fewer partitions, or to the same number of +        // partitions with better score, it is a better partitioning. +        if (NumPartitions < MinPartitions[i] || +            (NumPartitions == MinPartitions[i] && Score > PartitionsScore[i])) { +          MinPartitions[i] = NumPartitions; +          LastElement[i] = j; +          PartitionsScore[i] = Score; +        } +      } +    } +  } + +  // Iterate over the partitions, replacing some with jump tables in-place. +  unsigned DstIndex = 0; +  for (unsigned First = 0, Last; First < N; First = Last + 1) { +    Last = LastElement[First]; +    assert(Last >= First); +    assert(DstIndex <= First); +    unsigned NumClusters = Last - First + 1; + +    CaseCluster JTCluster; +    if (NumClusters >= MinJumpTableEntries && +        buildJumpTable(Clusters, First, Last, SI, DefaultMBB, JTCluster)) { +      Clusters[DstIndex++] = JTCluster; +    } else { +      for (unsigned I = First; I <= Last; ++I) +        std::memmove(&Clusters[DstIndex++], &Clusters[I], sizeof(Clusters[I])); +    } +  } +  Clusters.resize(DstIndex); +} + +bool SelectionDAGBuilder::buildBitTests(CaseClusterVector &Clusters, +                                        unsigned First, unsigned Last, +                                        const SwitchInst *SI, +                                        CaseCluster &BTCluster) { +  assert(First <= Last); +  if (First == Last) +    return false; + +  BitVector Dests(FuncInfo.MF->getNumBlockIDs()); +  unsigned NumCmps = 0; +  for (int64_t I = First; I <= Last; ++I) { +    assert(Clusters[I].Kind == CC_Range); +    Dests.set(Clusters[I].MBB->getNumber()); +    NumCmps += (Clusters[I].Low == Clusters[I].High) ? 1 : 2; +  } +  unsigned NumDests = Dests.count(); + +  APInt Low = Clusters[First].Low->getValue(); +  APInt High = Clusters[Last].High->getValue(); +  assert(Low.slt(High)); + +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  const DataLayout &DL = DAG.getDataLayout(); +  if (!TLI.isSuitableForBitTests(NumDests, NumCmps, Low, High, DL)) +    return false; + +  APInt LowBound; +  APInt CmpRange; + +  const int BitWidth = TLI.getPointerTy(DL).getSizeInBits(); +  assert(TLI.rangeFitsInWord(Low, High, DL) && +         "Case range must fit in bit mask!"); + +  // Check if the clusters cover a contiguous range such that no value in the +  // range will jump to the default statement. +  bool ContiguousRange = true; +  for (int64_t I = First + 1; I <= Last; ++I) { +    if (Clusters[I].Low->getValue() != Clusters[I - 1].High->getValue() + 1) { +      ContiguousRange = false; +      break; +    } +  } + +  if (Low.isStrictlyPositive() && High.slt(BitWidth)) { +    // Optimize the case where all the case values fit in a word without having +    // to subtract minValue. In this case, we can optimize away the subtraction. +    LowBound = APInt::getNullValue(Low.getBitWidth()); +    CmpRange = High; +    ContiguousRange = false; +  } else { +    LowBound = Low; +    CmpRange = High - Low; +  } + +  CaseBitsVector CBV; +  auto TotalProb = BranchProbability::getZero(); +  for (unsigned i = First; i <= Last; ++i) { +    // Find the CaseBits for this destination. +    unsigned j; +    for (j = 0; j < CBV.size(); ++j) +      if (CBV[j].BB == Clusters[i].MBB) +        break; +    if (j == CBV.size()) +      CBV.push_back( +          CaseBits(0, Clusters[i].MBB, 0, BranchProbability::getZero())); +    CaseBits *CB = &CBV[j]; + +    // Update Mask, Bits and ExtraProb. +    uint64_t Lo = (Clusters[i].Low->getValue() - LowBound).getZExtValue(); +    uint64_t Hi = (Clusters[i].High->getValue() - LowBound).getZExtValue(); +    assert(Hi >= Lo && Hi < 64 && "Invalid bit case!"); +    CB->Mask |= (-1ULL >> (63 - (Hi - Lo))) << Lo; +    CB->Bits += Hi - Lo + 1; +    CB->ExtraProb += Clusters[i].Prob; +    TotalProb += Clusters[i].Prob; +  } + +  BitTestInfo BTI; +  std::sort(CBV.begin(), CBV.end(), [](const CaseBits &a, const CaseBits &b) { +    // Sort by probability first, number of bits second. +    if (a.ExtraProb != b.ExtraProb) +      return a.ExtraProb > b.ExtraProb; +    return a.Bits > b.Bits; +  }); + +  for (auto &CB : CBV) { +    MachineBasicBlock *BitTestBB = +        FuncInfo.MF->CreateMachineBasicBlock(SI->getParent()); +    BTI.push_back(BitTestCase(CB.Mask, BitTestBB, CB.BB, CB.ExtraProb)); +  } +  BitTestCases.emplace_back(std::move(LowBound), std::move(CmpRange), +                            SI->getCondition(), -1U, MVT::Other, false, +                            ContiguousRange, nullptr, nullptr, std::move(BTI), +                            TotalProb); + +  BTCluster = CaseCluster::bitTests(Clusters[First].Low, Clusters[Last].High, +                                    BitTestCases.size() - 1, TotalProb); +  return true; +} + +void SelectionDAGBuilder::findBitTestClusters(CaseClusterVector &Clusters, +                                              const SwitchInst *SI) { +// Partition Clusters into as few subsets as possible, where each subset has a +// range that fits in a machine word and has <= 3 unique destinations. + +#ifndef NDEBUG +  // Clusters must be sorted and contain Range or JumpTable clusters. +  assert(!Clusters.empty()); +  assert(Clusters[0].Kind == CC_Range || Clusters[0].Kind == CC_JumpTable); +  for (const CaseCluster &C : Clusters) +    assert(C.Kind == CC_Range || C.Kind == CC_JumpTable); +  for (unsigned i = 1; i < Clusters.size(); ++i) +    assert(Clusters[i-1].High->getValue().slt(Clusters[i].Low->getValue())); +#endif + +  // The algorithm below is not suitable for -O0. +  if (TM.getOptLevel() == CodeGenOpt::None) +    return; + +  // If target does not have legal shift left, do not emit bit tests at all. +  const TargetLowering &TLI = DAG.getTargetLoweringInfo(); +  const DataLayout &DL = DAG.getDataLayout(); + +  EVT PTy = TLI.getPointerTy(DL); +  if (!TLI.isOperationLegal(ISD::SHL, PTy)) +    return; + +  int BitWidth = PTy.getSizeInBits(); +  const int64_t N = Clusters.size(); + +  // MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1]. +  SmallVector<unsigned, 8> MinPartitions(N); +  // LastElement[i] is the last element of the partition starting at i. +  SmallVector<unsigned, 8> LastElement(N); + +  // FIXME: This might not be the best algorithm for finding bit test clusters. + +  // Base case: There is only one way to partition Clusters[N-1]. +  MinPartitions[N - 1] = 1; +  LastElement[N - 1] = N - 1; + +  // Note: loop indexes are signed to avoid underflow. +  for (int64_t i = N - 2; i >= 0; --i) { +    // Find optimal partitioning of Clusters[i..N-1]. +    // Baseline: Put Clusters[i] into a partition on its own. +    MinPartitions[i] = MinPartitions[i + 1] + 1; +    LastElement[i] = i; + +    // Search for a solution that results in fewer partitions. +    // Note: the search is limited by BitWidth, reducing time complexity. +    for (int64_t j = std::min(N - 1, i + BitWidth - 1); j > i; --j) { +      // Try building a partition from Clusters[i..j]. + +      // Check the range. +      if (!TLI.rangeFitsInWord(Clusters[i].Low->getValue(), +                               Clusters[j].High->getValue(), DL)) +        continue; + +      // Check nbr of destinations and cluster types. +      // FIXME: This works, but doesn't seem very efficient. +      bool RangesOnly = true; +      BitVector Dests(FuncInfo.MF->getNumBlockIDs()); +      for (int64_t k = i; k <= j; k++) { +        if (Clusters[k].Kind != CC_Range) { +          RangesOnly = false; +          break; +        } +        Dests.set(Clusters[k].MBB->getNumber()); +      } +      if (!RangesOnly || Dests.count() > 3) +        break; + +      // Check if it's a better partition. +      unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]); +      if (NumPartitions < MinPartitions[i]) { +        // Found a better partition. +        MinPartitions[i] = NumPartitions; +        LastElement[i] = j; +      } +    } +  } + +  // Iterate over the partitions, replacing with bit-test clusters in-place. +  unsigned DstIndex = 0; +  for (unsigned First = 0, Last; First < N; First = Last + 1) { +    Last = LastElement[First]; +    assert(First <= Last); +    assert(DstIndex <= First); + +    CaseCluster BitTestCluster; +    if (buildBitTests(Clusters, First, Last, SI, BitTestCluster)) { +      Clusters[DstIndex++] = BitTestCluster; +    } else { +      size_t NumClusters = Last - First + 1; +      std::memmove(&Clusters[DstIndex], &Clusters[First], +                   sizeof(Clusters[0]) * NumClusters); +      DstIndex += NumClusters; +    } +  } +  Clusters.resize(DstIndex); +} + +void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond, +                                        MachineBasicBlock *SwitchMBB, +                                        MachineBasicBlock *DefaultMBB) { +  MachineFunction *CurMF = FuncInfo.MF; +  MachineBasicBlock *NextMBB = nullptr; +  MachineFunction::iterator BBI(W.MBB); +  if (++BBI != FuncInfo.MF->end()) +    NextMBB = &*BBI; + +  unsigned Size = W.LastCluster - W.FirstCluster + 1; + +  BranchProbabilityInfo *BPI = FuncInfo.BPI; + +  if (Size == 2 && W.MBB == SwitchMBB) { +    // If any two of the cases has the same destination, and if one value +    // is the same as the other, but has one bit unset that the other has set, +    // use bit manipulation to do two compares at once.  For example: +    // "if (X == 6 || X == 4)" -> "if ((X|2) == 6)" +    // TODO: This could be extended to merge any 2 cases in switches with 3 +    // cases. +    // TODO: Handle cases where W.CaseBB != SwitchBB. +    CaseCluster &Small = *W.FirstCluster; +    CaseCluster &Big = *W.LastCluster; + +    if (Small.Low == Small.High && Big.Low == Big.High && +        Small.MBB == Big.MBB) { +      const APInt &SmallValue = Small.Low->getValue(); +      const APInt &BigValue = Big.Low->getValue(); + +      // Check that there is only one bit different. +      APInt CommonBit = BigValue ^ SmallValue; +      if (CommonBit.isPowerOf2()) { +        SDValue CondLHS = getValue(Cond); +        EVT VT = CondLHS.getValueType(); +        SDLoc DL = getCurSDLoc(); + +        SDValue Or = DAG.getNode(ISD::OR, DL, VT, CondLHS, +                                 DAG.getConstant(CommonBit, DL, VT)); +        SDValue Cond = DAG.getSetCC( +            DL, MVT::i1, Or, DAG.getConstant(BigValue | SmallValue, DL, VT), +            ISD::SETEQ); + +        // Update successor info. +        // Both Small and Big will jump to Small.BB, so we sum up the +        // probabilities. +        addSuccessorWithProb(SwitchMBB, Small.MBB, Small.Prob + Big.Prob); +        if (BPI) +          addSuccessorWithProb( +              SwitchMBB, DefaultMBB, +              // The default destination is the first successor in IR. +              BPI->getEdgeProbability(SwitchMBB->getBasicBlock(), (unsigned)0)); +        else +          addSuccessorWithProb(SwitchMBB, DefaultMBB); + +        // Insert the true branch. +        SDValue BrCond = +            DAG.getNode(ISD::BRCOND, DL, MVT::Other, getControlRoot(), Cond, +                        DAG.getBasicBlock(Small.MBB)); +        // Insert the false branch. +        BrCond = DAG.getNode(ISD::BR, DL, MVT::Other, BrCond, +                             DAG.getBasicBlock(DefaultMBB)); + +        DAG.setRoot(BrCond); +        return; +      } +    } +  } + +  if (TM.getOptLevel() != CodeGenOpt::None) { +    // Order cases by probability so the most likely case will be checked first. +    std::sort(W.FirstCluster, W.LastCluster + 1, +              [](const CaseCluster &a, const CaseCluster &b) { +      return a.Prob > b.Prob; +    }); + +    // Rearrange the case blocks so that the last one falls through if possible +    // without without changing the order of probabilities. +    for (CaseClusterIt I = W.LastCluster; I > W.FirstCluster; ) { +      --I; +      if (I->Prob > W.LastCluster->Prob) +        break; +      if (I->Kind == CC_Range && I->MBB == NextMBB) { +        std::swap(*I, *W.LastCluster); +        break; +      } +    } +  } + +  // Compute total probability. +  BranchProbability DefaultProb = W.DefaultProb; +  BranchProbability UnhandledProbs = DefaultProb; +  for (CaseClusterIt I = W.FirstCluster; I <= W.LastCluster; ++I) +    UnhandledProbs += I->Prob; + +  MachineBasicBlock *CurMBB = W.MBB; +  for (CaseClusterIt I = W.FirstCluster, E = W.LastCluster; I <= E; ++I) { +    MachineBasicBlock *Fallthrough; +    if (I == W.LastCluster) { +      // For the last cluster, fall through to the default destination. +      Fallthrough = DefaultMBB; +    } else { +      Fallthrough = CurMF->CreateMachineBasicBlock(CurMBB->getBasicBlock()); +      CurMF->insert(BBI, Fallthrough); +      // Put Cond in a virtual register to make it available from the new blocks. +      ExportFromCurrentBlock(Cond); +    } +    UnhandledProbs -= I->Prob; + +    switch (I->Kind) { +      case CC_JumpTable: { +        // FIXME: Optimize away range check based on pivot comparisons. +        JumpTableHeader *JTH = &JTCases[I->JTCasesIndex].first; +        JumpTable *JT = &JTCases[I->JTCasesIndex].second; + +        // The jump block hasn't been inserted yet; insert it here. +        MachineBasicBlock *JumpMBB = JT->MBB; +        CurMF->insert(BBI, JumpMBB); + +        auto JumpProb = I->Prob; +        auto FallthroughProb = UnhandledProbs; + +        // If the default statement is a target of the jump table, we evenly +        // distribute the default probability to successors of CurMBB. Also +        // update the probability on the edge from JumpMBB to Fallthrough. +        for (MachineBasicBlock::succ_iterator SI = JumpMBB->succ_begin(), +                                              SE = JumpMBB->succ_end(); +             SI != SE; ++SI) { +          if (*SI == DefaultMBB) { +            JumpProb += DefaultProb / 2; +            FallthroughProb -= DefaultProb / 2; +            JumpMBB->setSuccProbability(SI, DefaultProb / 2); +            JumpMBB->normalizeSuccProbs(); +            break; +          } +        } + +        addSuccessorWithProb(CurMBB, Fallthrough, FallthroughProb); +        addSuccessorWithProb(CurMBB, JumpMBB, JumpProb); +        CurMBB->normalizeSuccProbs(); + +        // The jump table header will be inserted in our current block, do the +        // range check, and fall through to our fallthrough block. +        JTH->HeaderBB = CurMBB; +        JT->Default = Fallthrough; // FIXME: Move Default to JumpTableHeader. + +        // If we're in the right place, emit the jump table header right now. +        if (CurMBB == SwitchMBB) { +          visitJumpTableHeader(*JT, *JTH, SwitchMBB); +          JTH->Emitted = true; +        } +        break; +      } +      case CC_BitTests: { +        // FIXME: Optimize away range check based on pivot comparisons. +        BitTestBlock *BTB = &BitTestCases[I->BTCasesIndex]; + +        // The bit test blocks haven't been inserted yet; insert them here. +        for (BitTestCase &BTC : BTB->Cases) +          CurMF->insert(BBI, BTC.ThisBB); + +        // Fill in fields of the BitTestBlock. +        BTB->Parent = CurMBB; +        BTB->Default = Fallthrough; + +        BTB->DefaultProb = UnhandledProbs; +        // If the cases in bit test don't form a contiguous range, we evenly +        // distribute the probability on the edge to Fallthrough to two +        // successors of CurMBB. +        if (!BTB->ContiguousRange) { +          BTB->Prob += DefaultProb / 2; +          BTB->DefaultProb -= DefaultProb / 2; +        } + +        // If we're in the right place, emit the bit test header right now. +        if (CurMBB == SwitchMBB) { +          visitBitTestHeader(*BTB, SwitchMBB); +          BTB->Emitted = true; +        } +        break; +      } +      case CC_Range: { +        const Value *RHS, *LHS, *MHS; +        ISD::CondCode CC; +        if (I->Low == I->High) { +          // Check Cond == I->Low. +          CC = ISD::SETEQ; +          LHS = Cond; +          RHS=I->Low; +          MHS = nullptr; +        } else { +          // Check I->Low <= Cond <= I->High. +          CC = ISD::SETLE; +          LHS = I->Low; +          MHS = Cond; +          RHS = I->High; +        } + +        // The false probability is the sum of all unhandled cases. +        CaseBlock CB(CC, LHS, RHS, MHS, I->MBB, Fallthrough, CurMBB, I->Prob, +                     UnhandledProbs); + +        if (CurMBB == SwitchMBB) +          visitSwitchCase(CB, SwitchMBB); +        else +          SwitchCases.push_back(CB); + +        break; +      } +    } +    CurMBB = Fallthrough; +  } +} + +unsigned SelectionDAGBuilder::caseClusterRank(const CaseCluster &CC, +                                              CaseClusterIt First, +                                              CaseClusterIt Last) { +  return std::count_if(First, Last + 1, [&](const CaseCluster &X) { +    if (X.Prob != CC.Prob) +      return X.Prob > CC.Prob; + +    // Ties are broken by comparing the case value. +    return X.Low->getValue().slt(CC.Low->getValue()); +  }); +} + +void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList, +                                        const SwitchWorkListItem &W, +                                        Value *Cond, +                                        MachineBasicBlock *SwitchMBB) { +  assert(W.FirstCluster->Low->getValue().slt(W.LastCluster->Low->getValue()) && +         "Clusters not sorted?"); + +  assert(W.LastCluster - W.FirstCluster + 1 >= 2 && "Too small to split!"); + +  // Balance the tree based on branch probabilities to create a near-optimal (in +  // terms of search time given key frequency) binary search tree. See e.g. Kurt +  // Mehlhorn "Nearly Optimal Binary Search Trees" (1975). +  CaseClusterIt LastLeft = W.FirstCluster; +  CaseClusterIt FirstRight = W.LastCluster; +  auto LeftProb = LastLeft->Prob + W.DefaultProb / 2; +  auto RightProb = FirstRight->Prob + W.DefaultProb / 2; + +  // Move LastLeft and FirstRight towards each other from opposite directions to +  // find a partitioning of the clusters which balances the probability on both +  // sides. If LeftProb and RightProb are equal, alternate which side is +  // taken to ensure 0-probability nodes are distributed evenly. +  unsigned I = 0; +  while (LastLeft + 1 < FirstRight) { +    if (LeftProb < RightProb || (LeftProb == RightProb && (I & 1))) +      LeftProb += (++LastLeft)->Prob; +    else +      RightProb += (--FirstRight)->Prob; +    I++; +  } + +  for (;;) { +    // Our binary search tree differs from a typical BST in that ours can have up +    // to three values in each leaf. The pivot selection above doesn't take that +    // into account, which means the tree might require more nodes and be less +    // efficient. We compensate for this here. + +    unsigned NumLeft = LastLeft - W.FirstCluster + 1; +    unsigned NumRight = W.LastCluster - FirstRight + 1; + +    if (std::min(NumLeft, NumRight) < 3 && std::max(NumLeft, NumRight) > 3) { +      // If one side has less than 3 clusters, and the other has more than 3, +      // consider taking a cluster from the other side. + +      if (NumLeft < NumRight) { +        // Consider moving the first cluster on the right to the left side. +        CaseCluster &CC = *FirstRight; +        unsigned RightSideRank = caseClusterRank(CC, FirstRight, W.LastCluster); +        unsigned LeftSideRank = caseClusterRank(CC, W.FirstCluster, LastLeft); +        if (LeftSideRank <= RightSideRank) { +          // Moving the cluster to the left does not demote it. +          ++LastLeft; +          ++FirstRight; +          continue; +        } +      } else { +        assert(NumRight < NumLeft); +        // Consider moving the last element on the left to the right side. +        CaseCluster &CC = *LastLeft; +        unsigned LeftSideRank = caseClusterRank(CC, W.FirstCluster, LastLeft); +        unsigned RightSideRank = caseClusterRank(CC, FirstRight, W.LastCluster); +        if (RightSideRank <= LeftSideRank) { +          // Moving the cluster to the right does not demot it. +          --LastLeft; +          --FirstRight; +          continue; +        } +      } +    } +    break; +  } + +  assert(LastLeft + 1 == FirstRight); +  assert(LastLeft >= W.FirstCluster); +  assert(FirstRight <= W.LastCluster); + +  // Use the first element on the right as pivot since we will make less-than +  // comparisons against it. +  CaseClusterIt PivotCluster = FirstRight; +  assert(PivotCluster > W.FirstCluster); +  assert(PivotCluster <= W.LastCluster); + +  CaseClusterIt FirstLeft = W.FirstCluster; +  CaseClusterIt LastRight = W.LastCluster; + +  const ConstantInt *Pivot = PivotCluster->Low; + +  // New blocks will be inserted immediately after the current one. +  MachineFunction::iterator BBI(W.MBB); +  ++BBI; + +  // We will branch to the LHS if Value < Pivot. If LHS is a single cluster, +  // we can branch to its destination directly if it's squeezed exactly in +  // between the known lower bound and Pivot - 1. +  MachineBasicBlock *LeftMBB; +  if (FirstLeft == LastLeft && FirstLeft->Kind == CC_Range && +      FirstLeft->Low == W.GE && +      (FirstLeft->High->getValue() + 1LL) == Pivot->getValue()) { +    LeftMBB = FirstLeft->MBB; +  } else { +    LeftMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock()); +    FuncInfo.MF->insert(BBI, LeftMBB); +    WorkList.push_back( +        {LeftMBB, FirstLeft, LastLeft, W.GE, Pivot, W.DefaultProb / 2}); +    // Put Cond in a virtual register to make it available from the new blocks. +    ExportFromCurrentBlock(Cond); +  } + +  // Similarly, we will branch to the RHS if Value >= Pivot. If RHS is a +  // single cluster, RHS.Low == Pivot, and we can branch to its destination +  // directly if RHS.High equals the current upper bound. +  MachineBasicBlock *RightMBB; +  if (FirstRight == LastRight && FirstRight->Kind == CC_Range && +      W.LT && (FirstRight->High->getValue() + 1ULL) == W.LT->getValue()) { +    RightMBB = FirstRight->MBB; +  } else { +    RightMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock()); +    FuncInfo.MF->insert(BBI, RightMBB); +    WorkList.push_back( +        {RightMBB, FirstRight, LastRight, Pivot, W.LT, W.DefaultProb / 2}); +    // Put Cond in a virtual register to make it available from the new blocks. +    ExportFromCurrentBlock(Cond); +  } + +  // Create the CaseBlock record that will be used to lower the branch. +  CaseBlock CB(ISD::SETLT, Cond, Pivot, nullptr, LeftMBB, RightMBB, W.MBB, +               LeftProb, RightProb); + +  if (W.MBB == SwitchMBB) +    visitSwitchCase(CB, SwitchMBB); +  else +    SwitchCases.push_back(CB); +} + +void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) { +  // Extract cases from the switch. +  BranchProbabilityInfo *BPI = FuncInfo.BPI; +  CaseClusterVector Clusters; +  Clusters.reserve(SI.getNumCases()); +  for (auto I : SI.cases()) { +    MachineBasicBlock *Succ = FuncInfo.MBBMap[I.getCaseSuccessor()]; +    const ConstantInt *CaseVal = I.getCaseValue(); +    BranchProbability Prob = +        BPI ? BPI->getEdgeProbability(SI.getParent(), I.getSuccessorIndex()) +            : BranchProbability(1, SI.getNumCases() + 1); +    Clusters.push_back(CaseCluster::range(CaseVal, CaseVal, Succ, Prob)); +  } + +  MachineBasicBlock *DefaultMBB = FuncInfo.MBBMap[SI.getDefaultDest()]; + +  // Cluster adjacent cases with the same destination. We do this at all +  // optimization levels because it's cheap to do and will make codegen faster +  // if there are many clusters. +  sortAndRangeify(Clusters); + +  if (TM.getOptLevel() != CodeGenOpt::None) { +    // Replace an unreachable default with the most popular destination. +    // FIXME: Exploit unreachable default more aggressively. +    bool UnreachableDefault = +        isa<UnreachableInst>(SI.getDefaultDest()->getFirstNonPHIOrDbg()); +    if (UnreachableDefault && !Clusters.empty()) { +      DenseMap<const BasicBlock *, unsigned> Popularity; +      unsigned MaxPop = 0; +      const BasicBlock *MaxBB = nullptr; +      for (auto I : SI.cases()) { +        const BasicBlock *BB = I.getCaseSuccessor(); +        if (++Popularity[BB] > MaxPop) { +          MaxPop = Popularity[BB]; +          MaxBB = BB; +        } +      } +      // Set new default. +      assert(MaxPop > 0 && MaxBB); +      DefaultMBB = FuncInfo.MBBMap[MaxBB]; + +      // Remove cases that were pointing to the destination that is now the +      // default. +      CaseClusterVector New; +      New.reserve(Clusters.size()); +      for (CaseCluster &CC : Clusters) { +        if (CC.MBB != DefaultMBB) +          New.push_back(CC); +      } +      Clusters = std::move(New); +    } +  } + +  // If there is only the default destination, jump there directly. +  MachineBasicBlock *SwitchMBB = FuncInfo.MBB; +  if (Clusters.empty()) { +    SwitchMBB->addSuccessor(DefaultMBB); +    if (DefaultMBB != NextBlock(SwitchMBB)) { +      DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other, +                              getControlRoot(), DAG.getBasicBlock(DefaultMBB))); +    } +    return; +  } + +  findJumpTables(Clusters, &SI, DefaultMBB); +  findBitTestClusters(Clusters, &SI); + +  DEBUG({ +    dbgs() << "Case clusters: "; +    for (const CaseCluster &C : Clusters) { +      if (C.Kind == CC_JumpTable) dbgs() << "JT:"; +      if (C.Kind == CC_BitTests) dbgs() << "BT:"; + +      C.Low->getValue().print(dbgs(), true); +      if (C.Low != C.High) { +        dbgs() << '-'; +        C.High->getValue().print(dbgs(), true); +      } +      dbgs() << ' '; +    } +    dbgs() << '\n'; +  }); + +  assert(!Clusters.empty()); +  SwitchWorkList WorkList; +  CaseClusterIt First = Clusters.begin(); +  CaseClusterIt Last = Clusters.end() - 1; +  auto DefaultProb = getEdgeProbability(SwitchMBB, DefaultMBB); +  WorkList.push_back({SwitchMBB, First, Last, nullptr, nullptr, DefaultProb}); + +  while (!WorkList.empty()) { +    SwitchWorkListItem W = WorkList.back(); +    WorkList.pop_back(); +    unsigned NumClusters = W.LastCluster - W.FirstCluster + 1; + +    if (NumClusters > 3 && TM.getOptLevel() != CodeGenOpt::None && +        !DefaultMBB->getParent()->getFunction()->optForMinSize()) { +      // For optimized builds, lower large range as a balanced binary tree. +      splitWorkItem(WorkList, W, SI.getCondition(), SwitchMBB); +      continue; +    } + +    lowerWorkItem(W, SI.getCondition(), SwitchMBB, DefaultMBB); +  } +}  | 
