vendor/llvm/llvm-trunk-r300422

1 files changed, 516 insertions, 0 deletions

diff --git a/lib/Target/X86/X86InstructionSelector.cpp b/lib/Target/X86/X86InstructionSelector.cpp
new file mode 100644
index 0000000000000..6cc5e8b635975
--- /dev/null
+++ b/lib/Target/X86/X86InstructionSelector.cpp
@@ -0,0 +1,516 @@
+//===- X86InstructionSelector.cpp ----------------------------*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file implements the targeting of the InstructionSelector class for
+/// X86.
+/// \todo This should be generated by TableGen.
+//===----------------------------------------------------------------------===//
+
+#include "X86InstrBuilder.h"
+#include "X86InstrInfo.h"
+#include "X86RegisterBankInfo.h"
+#include "X86RegisterInfo.h"
+#include "X86Subtarget.h"
+#include "X86TargetMachine.h"
+#include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineOperand.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/IR/Type.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+
+#define DEBUG_TYPE "X86-isel"
+
+using namespace llvm;
+
+#ifndef LLVM_BUILD_GLOBAL_ISEL
+#error "You shouldn't build this"
+#endif
+
+namespace {
+
+class X86InstructionSelector : public InstructionSelector {
+public:
+  X86InstructionSelector(const X86Subtarget &STI,
+                         const X86RegisterBankInfo &RBI);
+
+  bool select(MachineInstr &I) const override;
+
+private:
+  /// tblgen-erated 'select' implementation, used as the initial selector for
+  /// the patterns that don't require complex C++.
+  bool selectImpl(MachineInstr &I) const;
+
+  // TODO: remove after selectImpl support pattern with a predicate.
+  unsigned getFAddOp(LLT &Ty, const RegisterBank &RB) const;
+  unsigned getFSubOp(LLT &Ty, const RegisterBank &RB) const;
+  unsigned getAddOp(LLT &Ty, const RegisterBank &RB) const;
+  unsigned getSubOp(LLT &Ty, const RegisterBank &RB) const;
+  unsigned getLoadStoreOp(LLT &Ty, const RegisterBank &RB, unsigned Opc,
+                          uint64_t Alignment) const;
+
+  bool selectBinaryOp(MachineInstr &I, MachineRegisterInfo &MRI,
+                      MachineFunction &MF) const;
+  bool selectLoadStoreOp(MachineInstr &I, MachineRegisterInfo &MRI,
+                         MachineFunction &MF) const;
+  bool selectFrameIndex(MachineInstr &I, MachineRegisterInfo &MRI,
+                        MachineFunction &MF) const;
+  bool selectConstant(MachineInstr &I, MachineRegisterInfo &MRI,
+                      MachineFunction &MF) const;
+
+  const X86Subtarget &STI;
+  const X86InstrInfo &TII;
+  const X86RegisterInfo &TRI;
+  const X86RegisterBankInfo &RBI;
+
+#define GET_GLOBALISEL_TEMPORARIES_DECL
+#include "X86GenGlobalISel.inc"
+#undef GET_GLOBALISEL_TEMPORARIES_DECL
+};
+
+} // end anonymous namespace
+
+#define GET_GLOBALISEL_IMPL
+#include "X86GenGlobalISel.inc"
+#undef GET_GLOBALISEL_IMPL
+
+X86InstructionSelector::X86InstructionSelector(const X86Subtarget &STI,
+                                               const X86RegisterBankInfo &RBI)
+    : InstructionSelector(), STI(STI), TII(*STI.getInstrInfo()),
+      TRI(*STI.getRegisterInfo()), RBI(RBI)
+#define GET_GLOBALISEL_TEMPORARIES_INIT
+#include "X86GenGlobalISel.inc"
+#undef GET_GLOBALISEL_TEMPORARIES_INIT
+{
+}
+
+// FIXME: This should be target-independent, inferred from the types declared
+// for each class in the bank.
+static const TargetRegisterClass *
+getRegClassForTypeOnBank(LLT Ty, const RegisterBank &RB) {
+  if (RB.getID() == X86::GPRRegBankID) {
+    if (Ty.getSizeInBits() == 32)
+      return &X86::GR32RegClass;
+    if (Ty.getSizeInBits() == 64)
+      return &X86::GR64RegClass;
+  }
+  if (RB.getID() == X86::VECRRegBankID) {
+    if (Ty.getSizeInBits() == 32)
+      return &X86::FR32XRegClass;
+    if (Ty.getSizeInBits() == 64)
+      return &X86::FR64XRegClass;
+    if (Ty.getSizeInBits() == 128)
+      return &X86::VR128XRegClass;
+    if (Ty.getSizeInBits() == 256)
+      return &X86::VR256XRegClass;
+    if (Ty.getSizeInBits() == 512)
+      return &X86::VR512RegClass;
+  }
+
+  llvm_unreachable("Unknown RegBank!");
+}
+
+// Set X86 Opcode and constrain DestReg.
+static bool selectCopy(MachineInstr &I, const TargetInstrInfo &TII,
+                       MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
+                       const RegisterBankInfo &RBI) {
+
+  unsigned DstReg = I.getOperand(0).getReg();
+  if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
+    assert(I.isCopy() && "Generic operators do not allow physical registers");
+    return true;
+  }
+
+  const RegisterBank &RegBank = *RBI.getRegBank(DstReg, MRI, TRI);
+  const unsigned DstSize = MRI.getType(DstReg).getSizeInBits();
+  (void)DstSize;
+  unsigned SrcReg = I.getOperand(1).getReg();
+  const unsigned SrcSize = RBI.getSizeInBits(SrcReg, MRI, TRI);
+  (void)SrcSize;
+  assert((!TargetRegisterInfo::isPhysicalRegister(SrcReg) || I.isCopy()) &&
+         "No phys reg on generic operators");
+  assert((DstSize == SrcSize ||
+          // Copies are a mean to setup initial types, the number of
+          // bits may not exactly match.
+          (TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
+           DstSize <= RBI.getSizeInBits(SrcReg, MRI, TRI))) &&
+         "Copy with different width?!");
+
+  const TargetRegisterClass *RC = nullptr;
+
+  switch (RegBank.getID()) {
+  case X86::GPRRegBankID:
+    assert((DstSize <= 64) && "GPRs cannot get more than 64-bit width values.");
+    RC = getRegClassForTypeOnBank(MRI.getType(DstReg), RegBank);
+    break;
+  case X86::VECRRegBankID:
+    RC = getRegClassForTypeOnBank(MRI.getType(DstReg), RegBank);
+    break;
+  default:
+    llvm_unreachable("Unknown RegBank!");
+  }
+
+  // No need to constrain SrcReg. It will get constrained when
+  // we hit another of its use or its defs.
+  // Copies do not have constraints.
+  const TargetRegisterClass *OldRC = MRI.getRegClassOrNull(DstReg);
+  if (!OldRC || !RC->hasSubClassEq(OldRC)) {
+    if (!RBI.constrainGenericRegister(DstReg, *RC, MRI)) {
+      DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
+                   << " operand\n");
+      return false;
+    }
+  }
+  I.setDesc(TII.get(X86::COPY));
+  return true;
+}
+
+bool X86InstructionSelector::select(MachineInstr &I) const {
+  assert(I.getParent() && "Instruction should be in a basic block!");
+  assert(I.getParent()->getParent() && "Instruction should be in a function!");
+
+  MachineBasicBlock &MBB = *I.getParent();
+  MachineFunction &MF = *MBB.getParent();
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+
+  unsigned Opcode = I.getOpcode();
+  if (!isPreISelGenericOpcode(Opcode)) {
+    // Certain non-generic instructions also need some special handling.
+
+    if (I.isCopy())
+      return selectCopy(I, TII, MRI, TRI, RBI);
+
+    // TODO: handle more cases - LOAD_STACK_GUARD, PHI
+    return true;
+  }
+
+  assert(I.getNumOperands() == I.getNumExplicitOperands() &&
+         "Generic instruction has unexpected implicit operands\n");
+
+  // TODO: This should be implemented by tblgen, pattern with predicate not
+  // supported yet.
+  if (selectBinaryOp(I, MRI, MF))
+    return true;
+  if (selectLoadStoreOp(I, MRI, MF))
+    return true;
+  if (selectFrameIndex(I, MRI, MF))
+    return true;
+  if (selectConstant(I, MRI, MF))
+    return true;
+
+  return selectImpl(I);
+}
+
+unsigned X86InstructionSelector::getFAddOp(LLT &Ty,
+                                           const RegisterBank &RB) const {
+
+  if (X86::VECRRegBankID != RB.getID())
+    return TargetOpcode::G_FADD;
+
+  if (Ty == LLT::scalar(32)) {
+    if (STI.hasAVX512()) {
+      return X86::VADDSSZrr;
+    } else if (STI.hasAVX()) {
+      return X86::VADDSSrr;
+    } else if (STI.hasSSE1()) {
+      return X86::ADDSSrr;
+    }
+  } else if (Ty == LLT::scalar(64)) {
+    if (STI.hasAVX512()) {
+      return X86::VADDSDZrr;
+    } else if (STI.hasAVX()) {
+      return X86::VADDSDrr;
+    } else if (STI.hasSSE2()) {
+      return X86::ADDSDrr;
+    }
+  } else if (Ty == LLT::vector(4, 32)) {
+    if ((STI.hasAVX512()) && (STI.hasVLX())) {
+      return X86::VADDPSZ128rr;
+    } else if (STI.hasAVX()) {
+      return X86::VADDPSrr;
+    } else if (STI.hasSSE1()) {
+      return X86::ADDPSrr;
+    }
+  }
+
+  return TargetOpcode::G_FADD;
+}
+
+unsigned X86InstructionSelector::getFSubOp(LLT &Ty,
+                                           const RegisterBank &RB) const {
+
+  if (X86::VECRRegBankID != RB.getID())
+    return TargetOpcode::G_FSUB;
+
+  if (Ty == LLT::scalar(32)) {
+    if (STI.hasAVX512()) {
+      return X86::VSUBSSZrr;
+    } else if (STI.hasAVX()) {
+      return X86::VSUBSSrr;
+    } else if (STI.hasSSE1()) {
+      return X86::SUBSSrr;
+    }
+  } else if (Ty == LLT::scalar(64)) {
+    if (STI.hasAVX512()) {
+      return X86::VSUBSDZrr;
+    } else if (STI.hasAVX()) {
+      return X86::VSUBSDrr;
+    } else if (STI.hasSSE2()) {
+      return X86::SUBSDrr;
+    }
+  } else if (Ty == LLT::vector(4, 32)) {
+    if ((STI.hasAVX512()) && (STI.hasVLX())) {
+      return X86::VSUBPSZ128rr;
+    } else if (STI.hasAVX()) {
+      return X86::VSUBPSrr;
+    } else if (STI.hasSSE1()) {
+      return X86::SUBPSrr;
+    }
+  }
+
+  return TargetOpcode::G_FSUB;
+}
+
+unsigned X86InstructionSelector::getAddOp(LLT &Ty,
+                                          const RegisterBank &RB) const {
+
+  if (X86::VECRRegBankID != RB.getID())
+    return TargetOpcode::G_ADD;
+
+  if (Ty == LLT::vector(4, 32)) {
+    if (STI.hasAVX512() && STI.hasVLX()) {
+      return X86::VPADDDZ128rr;
+    } else if (STI.hasAVX()) {
+      return X86::VPADDDrr;
+    } else if (STI.hasSSE2()) {
+      return X86::PADDDrr;
+    }
+  }
+
+  return TargetOpcode::G_ADD;
+}
+
+unsigned X86InstructionSelector::getSubOp(LLT &Ty,
+                                          const RegisterBank &RB) const {
+
+  if (X86::VECRRegBankID != RB.getID())
+    return TargetOpcode::G_SUB;
+
+  if (Ty == LLT::vector(4, 32)) {
+    if (STI.hasAVX512() && STI.hasVLX()) {
+      return X86::VPSUBDZ128rr;
+    } else if (STI.hasAVX()) {
+      return X86::VPSUBDrr;
+    } else if (STI.hasSSE2()) {
+      return X86::PSUBDrr;
+    }
+  }
+
+  return TargetOpcode::G_SUB;
+}
+
+bool X86InstructionSelector::selectBinaryOp(MachineInstr &I,
+                                            MachineRegisterInfo &MRI,
+                                            MachineFunction &MF) const {
+
+  const unsigned DefReg = I.getOperand(0).getReg();
+  LLT Ty = MRI.getType(DefReg);
+  const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
+
+  unsigned NewOpc = I.getOpcode();
+
+  switch (NewOpc) {
+  case TargetOpcode::G_FADD:
+    NewOpc = getFAddOp(Ty, RB);
+    break;
+  case TargetOpcode::G_FSUB:
+    NewOpc = getFSubOp(Ty, RB);
+    break;
+  case TargetOpcode::G_ADD:
+    NewOpc = getAddOp(Ty, RB);
+    break;
+  case TargetOpcode::G_SUB:
+    NewOpc = getSubOp(Ty, RB);
+    break;
+  default:
+    break;
+  }
+
+  if (NewOpc == I.getOpcode())
+    return false;
+
+  I.setDesc(TII.get(NewOpc));
+
+  return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
+}
+
+unsigned X86InstructionSelector::getLoadStoreOp(LLT &Ty, const RegisterBank &RB,
+                                                unsigned Opc,
+                                                uint64_t Alignment) const {
+  bool Isload = (Opc == TargetOpcode::G_LOAD);
+  bool HasAVX = STI.hasAVX();
+  bool HasAVX512 = STI.hasAVX512();
+  bool HasVLX = STI.hasVLX();
+
+  if (Ty == LLT::scalar(8)) {
+    if (X86::GPRRegBankID == RB.getID())
+      return Isload ? X86::MOV8rm : X86::MOV8mr;
+  } else if (Ty == LLT::scalar(16)) {
+    if (X86::GPRRegBankID == RB.getID())
+      return Isload ? X86::MOV16rm : X86::MOV16mr;
+  } else if (Ty == LLT::scalar(32)) {
+    if (X86::GPRRegBankID == RB.getID())
+      return Isload ? X86::MOV32rm : X86::MOV32mr;
+    if (X86::VECRRegBankID == RB.getID())
+      return Isload ? (HasAVX512 ? X86::VMOVSSZrm
+                                 : HasAVX ? X86::VMOVSSrm : X86::MOVSSrm)
+                    : (HasAVX512 ? X86::VMOVSSZmr
+                                 : HasAVX ? X86::VMOVSSmr : X86::MOVSSmr);
+  } else if (Ty == LLT::scalar(64)) {
+    if (X86::GPRRegBankID == RB.getID())
+      return Isload ? X86::MOV64rm : X86::MOV64mr;
+    if (X86::VECRRegBankID == RB.getID())
+      return Isload ? (HasAVX512 ? X86::VMOVSDZrm
+                                 : HasAVX ? X86::VMOVSDrm : X86::MOVSDrm)
+                    : (HasAVX512 ? X86::VMOVSDZmr
+                                 : HasAVX ? X86::VMOVSDmr : X86::MOVSDmr);
+  } else if (Ty.isVector() && Ty.getSizeInBits() == 128) {
+    if (Alignment >= 16)
+      return Isload ? (HasVLX ? X86::VMOVAPSZ128rm
+                              : HasAVX512
+                                    ? X86::VMOVAPSZ128rm_NOVLX
+                                    : HasAVX ? X86::VMOVAPSrm : X86::MOVAPSrm)
+                    : (HasVLX ? X86::VMOVAPSZ128mr
+                              : HasAVX512
+                                    ? X86::VMOVAPSZ128mr_NOVLX
+                                    : HasAVX ? X86::VMOVAPSmr : X86::MOVAPSmr);
+    else
+      return Isload ? (HasVLX ? X86::VMOVUPSZ128rm
+                              : HasAVX512
+                                    ? X86::VMOVUPSZ128rm_NOVLX
+                                    : HasAVX ? X86::VMOVUPSrm : X86::MOVUPSrm)
+                    : (HasVLX ? X86::VMOVUPSZ128mr
+                              : HasAVX512
+                                    ? X86::VMOVUPSZ128mr_NOVLX
+                                    : HasAVX ? X86::VMOVUPSmr : X86::MOVUPSmr);
+  }
+  return Opc;
+}
+
+bool X86InstructionSelector::selectLoadStoreOp(MachineInstr &I,
+                                               MachineRegisterInfo &MRI,
+                                               MachineFunction &MF) const {
+
+  unsigned Opc = I.getOpcode();
+
+  if (Opc != TargetOpcode::G_STORE && Opc != TargetOpcode::G_LOAD)
+    return false;
+
+  const unsigned DefReg = I.getOperand(0).getReg();
+  LLT Ty = MRI.getType(DefReg);
+  const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
+
+  auto &MemOp = **I.memoperands_begin();
+  unsigned NewOpc = getLoadStoreOp(Ty, RB, Opc, MemOp.getAlignment());
+  if (NewOpc == Opc)
+    return false;
+
+  I.setDesc(TII.get(NewOpc));
+  MachineInstrBuilder MIB(MF, I);
+  if (Opc == TargetOpcode::G_LOAD)
+    addOffset(MIB, 0);
+  else {
+    // G_STORE (VAL, Addr), X86Store instruction (Addr, VAL)
+    I.RemoveOperand(0);
+    addOffset(MIB, 0).addUse(DefReg);
+  }
+  return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
+}
+
+bool X86InstructionSelector::selectFrameIndex(MachineInstr &I,
+                                              MachineRegisterInfo &MRI,
+                                              MachineFunction &MF) const {
+  if (I.getOpcode() != TargetOpcode::G_FRAME_INDEX)
+    return false;
+
+  const unsigned DefReg = I.getOperand(0).getReg();
+  LLT Ty = MRI.getType(DefReg);
+
+  // Use LEA to calculate frame index.
+  unsigned NewOpc;
+  if (Ty == LLT::pointer(0, 64))
+    NewOpc = X86::LEA64r;
+  else if (Ty == LLT::pointer(0, 32))
+    NewOpc = STI.isTarget64BitILP32() ? X86::LEA64_32r : X86::LEA32r;
+  else
+    llvm_unreachable("Can't select G_FRAME_INDEX, unsupported type.");
+
+  I.setDesc(TII.get(NewOpc));
+  MachineInstrBuilder MIB(MF, I);
+  addOffset(MIB, 0);
+
+  return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
+}
+
+bool X86InstructionSelector::selectConstant(MachineInstr &I,
+                                            MachineRegisterInfo &MRI,
+                                            MachineFunction &MF) const {
+  if (I.getOpcode() != TargetOpcode::G_CONSTANT)
+    return false;
+
+  const unsigned DefReg = I.getOperand(0).getReg();
+  LLT Ty = MRI.getType(DefReg);
+
+  assert(Ty.isScalar() && "invalid element type.");
+
+  uint64_t Val = 0;
+  if (I.getOperand(1).isCImm()) {
+    Val = I.getOperand(1).getCImm()->getZExtValue();
+    I.getOperand(1).ChangeToImmediate(Val);
+  } else if (I.getOperand(1).isImm()) {
+    Val = I.getOperand(1).getImm();
+  } else
+    llvm_unreachable("Unsupported operand type.");
+
+  unsigned NewOpc;
+  switch (Ty.getSizeInBits()) {
+  case 8:
+    NewOpc = X86::MOV8ri;
+    break;
+  case 16:
+    NewOpc = X86::MOV16ri;
+    break;
+  case 32:
+    NewOpc = X86::MOV32ri;
+    break;
+  case 64: {
+    // TODO: in case isUInt<32>(Val), X86::MOV32ri can be used
+    if (isInt<32>(Val))
+      NewOpc = X86::MOV64ri32;
+    else
+      NewOpc = X86::MOV64ri;
+    break;
+  }
+  default:
+    llvm_unreachable("Can't select G_CONSTANT, unsupported type.");
+  }
+
+  I.setDesc(TII.get(NewOpc));
+  return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
+}
+
+InstructionSelector *
+llvm::createX86InstructionSelector(X86Subtarget &Subtarget,
+                                   X86RegisterBankInfo &RBI) {
+  return new X86InstructionSelector(Subtarget, RBI);
+}