1 files changed, 297 insertions, 0 deletions

diff --git a/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp b/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
new file mode 100644
index 000000000000..9592bc30a4e1
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
@@ -0,0 +1,297 @@
+//==- llvm/CodeGen/SelectionDAGAddressAnalysis.cpp - DAG Address Analysis --==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/SelectionDAGAddressAnalysis.h"
+#include "llvm/CodeGen/ISDOpcodes.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/CodeGen/SelectionDAGNodes.h"
+#include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/Support/Casting.h"
+#include <cstdint>
+
+using namespace llvm;
+
+bool BaseIndexOffset::equalBaseIndex(const BaseIndexOffset &Other,
+                                     const SelectionDAG &DAG,
+                                     int64_t &Off) const {
+  // Conservatively fail if we a match failed..
+  if (!Base.getNode() || !Other.Base.getNode())
+    return false;
+  if (!hasValidOffset() || !Other.hasValidOffset())
+    return false;
+  // Initial Offset difference.
+  Off = *Other.Offset - *Offset;
+
+  if ((Other.Index == Index) && (Other.IsIndexSignExt == IsIndexSignExt)) {
+    // Trivial match.
+    if (Other.Base == Base)
+      return true;
+
+    // Match GlobalAddresses
+    if (auto *A = dyn_cast<GlobalAddressSDNode>(Base))
+      if (auto *B = dyn_cast<GlobalAddressSDNode>(Other.Base))
+        if (A->getGlobal() == B->getGlobal()) {
+          Off += B->getOffset() - A->getOffset();
+          return true;
+        }
+
+    // Match Constants
+    if (auto *A = dyn_cast<ConstantPoolSDNode>(Base))
+      if (auto *B = dyn_cast<ConstantPoolSDNode>(Other.Base)) {
+        bool IsMatch =
+            A->isMachineConstantPoolEntry() == B->isMachineConstantPoolEntry();
+        if (IsMatch) {
+          if (A->isMachineConstantPoolEntry())
+            IsMatch = A->getMachineCPVal() == B->getMachineCPVal();
+          else
+            IsMatch = A->getConstVal() == B->getConstVal();
+        }
+        if (IsMatch) {
+          Off += B->getOffset() - A->getOffset();
+          return true;
+        }
+      }
+
+    const MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
+
+    // Match FrameIndexes.
+    if (auto *A = dyn_cast<FrameIndexSDNode>(Base))
+      if (auto *B = dyn_cast<FrameIndexSDNode>(Other.Base)) {
+        // Equal FrameIndexes - offsets are directly comparable.
+        if (A->getIndex() == B->getIndex())
+          return true;
+        // Non-equal FrameIndexes - If both frame indices are fixed
+        // we know their relative offsets and can compare them. Otherwise
+        // we must be conservative.
+        if (MFI.isFixedObjectIndex(A->getIndex()) &&
+            MFI.isFixedObjectIndex(B->getIndex())) {
+          Off += MFI.getObjectOffset(B->getIndex()) -
+                 MFI.getObjectOffset(A->getIndex());
+          return true;
+        }
+      }
+  }
+  return false;
+}
+
+bool BaseIndexOffset::computeAliasing(const SDNode *Op0,
+                                      const Optional<int64_t> NumBytes0,
+                                      const SDNode *Op1,
+                                      const Optional<int64_t> NumBytes1,
+                                      const SelectionDAG &DAG, bool &IsAlias) {
+
+  BaseIndexOffset BasePtr0 = match(Op0, DAG);
+  BaseIndexOffset BasePtr1 = match(Op1, DAG);
+
+  if (!(BasePtr0.getBase().getNode() && BasePtr1.getBase().getNode()))
+    return false;
+  int64_t PtrDiff;
+  if (NumBytes0.hasValue() && NumBytes1.hasValue() &&
+      BasePtr0.equalBaseIndex(BasePtr1, DAG, PtrDiff)) {
+    // BasePtr1 is PtrDiff away from BasePtr0. They alias if none of the
+    // following situations arise:
+    IsAlias = !(
+        // [----BasePtr0----]
+        //                         [---BasePtr1--]
+        // ========PtrDiff========>
+        (*NumBytes0 <= PtrDiff) ||
+        //                     [----BasePtr0----]
+        // [---BasePtr1--]
+        // =====(-PtrDiff)====>
+        (PtrDiff + *NumBytes1 <= 0)); // i.e. *NumBytes1 < -PtrDiff.
+    return true;
+  }
+  // If both BasePtr0 and BasePtr1 are FrameIndexes, we will not be
+  // able to calculate their relative offset if at least one arises
+  // from an alloca. However, these allocas cannot overlap and we
+  // can infer there is no alias.
+  if (auto *A = dyn_cast<FrameIndexSDNode>(BasePtr0.getBase()))
+    if (auto *B = dyn_cast<FrameIndexSDNode>(BasePtr1.getBase())) {
+      MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
+      // If the base are the same frame index but the we couldn't find a
+      // constant offset, (indices are different) be conservative.
+      if (A != B && (!MFI.isFixedObjectIndex(A->getIndex()) ||
+                     !MFI.isFixedObjectIndex(B->getIndex()))) {
+        IsAlias = false;
+        return true;
+      }
+    }
+
+  bool IsFI0 = isa<FrameIndexSDNode>(BasePtr0.getBase());
+  bool IsFI1 = isa<FrameIndexSDNode>(BasePtr1.getBase());
+  bool IsGV0 = isa<GlobalAddressSDNode>(BasePtr0.getBase());
+  bool IsGV1 = isa<GlobalAddressSDNode>(BasePtr1.getBase());
+  bool IsCV0 = isa<ConstantPoolSDNode>(BasePtr0.getBase());
+  bool IsCV1 = isa<ConstantPoolSDNode>(BasePtr1.getBase());
+
+  // If of mismatched base types or checkable indices we can check
+  // they do not alias.
+  if ((BasePtr0.getIndex() == BasePtr1.getIndex() || (IsFI0 != IsFI1) ||
+       (IsGV0 != IsGV1) || (IsCV0 != IsCV1)) &&
+      (IsFI0 || IsGV0 || IsCV0) && (IsFI1 || IsGV1 || IsCV1)) {
+    IsAlias = false;
+    return true;
+  }
+  return false; // Cannot determine whether the pointers alias.
+}
+
+bool BaseIndexOffset::contains(const SelectionDAG &DAG, int64_t BitSize,
+                               const BaseIndexOffset &Other,
+                               int64_t OtherBitSize, int64_t &BitOffset) const {
+  int64_t Offset;
+  if (!equalBaseIndex(Other, DAG, Offset))
+    return false;
+  if (Offset >= 0) {
+    // Other is after *this:
+    // [-------*this---------]
+    //            [---Other--]
+    // ==Offset==>
+    BitOffset = 8 * Offset;
+    return BitOffset + OtherBitSize <= BitSize;
+  }
+  // Other starts strictly before *this, it cannot be fully contained.
+  //    [-------*this---------]
+  // [--Other--]
+  return false;
+}
+
+/// Parses tree in Ptr for base, index, offset addresses.
+static BaseIndexOffset matchLSNode(const LSBaseSDNode *N,
+                                   const SelectionDAG &DAG) {
+  SDValue Ptr = N->getBasePtr();
+
+  // (((B + I*M) + c)) + c ...
+  SDValue Base = DAG.getTargetLoweringInfo().unwrapAddress(Ptr);
+  SDValue Index = SDValue();
+  int64_t Offset = 0;
+  bool IsIndexSignExt = false;
+
+  // pre-inc/pre-dec ops are components of EA.
+  if (N->getAddressingMode() == ISD::PRE_INC) {
+    if (auto *C = dyn_cast<ConstantSDNode>(N->getOffset()))
+      Offset += C->getSExtValue();
+    else // If unknown, give up now.
+      return BaseIndexOffset(SDValue(), SDValue(), 0, false);
+  } else if (N->getAddressingMode() == ISD::PRE_DEC) {
+    if (auto *C = dyn_cast<ConstantSDNode>(N->getOffset()))
+      Offset -= C->getSExtValue();
+    else // If unknown, give up now.
+      return BaseIndexOffset(SDValue(), SDValue(), 0, false);
+  }
+
+  // Consume constant adds & ors with appropriate masking.
+  while (true) {
+    switch (Base->getOpcode()) {
+    case ISD::OR:
+      // Only consider ORs which act as adds.
+      if (auto *C = dyn_cast<ConstantSDNode>(Base->getOperand(1)))
+        if (DAG.MaskedValueIsZero(Base->getOperand(0), C->getAPIntValue())) {
+          Offset += C->getSExtValue();
+          Base = DAG.getTargetLoweringInfo().unwrapAddress(Base->getOperand(0));
+          continue;
+        }
+      break;
+    case ISD::ADD:
+      if (auto *C = dyn_cast<ConstantSDNode>(Base->getOperand(1))) {
+        Offset += C->getSExtValue();
+        Base = DAG.getTargetLoweringInfo().unwrapAddress(Base->getOperand(0));
+        continue;
+      }
+      break;
+    case ISD::LOAD:
+    case ISD::STORE: {
+      auto *LSBase = cast<LSBaseSDNode>(Base.getNode());
+      unsigned int IndexResNo = (Base->getOpcode() == ISD::LOAD) ? 1 : 0;
+      if (LSBase->isIndexed() && Base.getResNo() == IndexResNo)
+        if (auto *C = dyn_cast<ConstantSDNode>(LSBase->getOffset())) {
+          auto Off = C->getSExtValue();
+          if (LSBase->getAddressingMode() == ISD::PRE_DEC ||
+              LSBase->getAddressingMode() == ISD::POST_DEC)
+            Offset -= Off;
+          else
+            Offset += Off;
+          Base = DAG.getTargetLoweringInfo().unwrapAddress(LSBase->getBasePtr());
+          continue;
+        }
+      break;
+    }
+    }
+    // If we get here break out of the loop.
+    break;
+  }
+
+  if (Base->getOpcode() == ISD::ADD) {
+    // TODO: The following code appears to be needless as it just
+    //       bails on some Ptrs early, reducing the cases where we
+    //       find equivalence. We should be able to remove this.
+    // Inside a loop the current BASE pointer is calculated using an ADD and a
+    // MUL instruction. In this case Base is the actual BASE pointer.
+    // (i64 add (i64 %array_ptr)
+    //          (i64 mul (i64 %induction_var)
+    //                   (i64 %element_size)))
+    if (Base->getOperand(1)->getOpcode() == ISD::MUL)
+      return BaseIndexOffset(Base, Index, Offset, IsIndexSignExt);
+
+    // Look at Base + Index + Offset cases.
+    Index = Base->getOperand(1);
+    SDValue PotentialBase = Base->getOperand(0);
+
+    // Skip signextends.
+    if (Index->getOpcode() == ISD::SIGN_EXTEND) {
+      Index = Index->getOperand(0);
+      IsIndexSignExt = true;
+    }
+
+    // Check if Index Offset pattern
+    if (Index->getOpcode() != ISD::ADD ||
+        !isa<ConstantSDNode>(Index->getOperand(1)))
+      return BaseIndexOffset(PotentialBase, Index, Offset, IsIndexSignExt);
+
+    Offset += cast<ConstantSDNode>(Index->getOperand(1))->getSExtValue();
+    Index = Index->getOperand(0);
+    if (Index->getOpcode() == ISD::SIGN_EXTEND) {
+      Index = Index->getOperand(0);
+      IsIndexSignExt = true;
+    } else
+      IsIndexSignExt = false;
+    Base = PotentialBase;
+  }
+  return BaseIndexOffset(Base, Index, Offset, IsIndexSignExt);
+}
+
+BaseIndexOffset BaseIndexOffset::match(const SDNode *N,
+                                       const SelectionDAG &DAG) {
+  if (const auto *LS0 = dyn_cast<LSBaseSDNode>(N))
+    return matchLSNode(LS0, DAG);
+  if (const auto *LN = dyn_cast<LifetimeSDNode>(N)) {
+    if (LN->hasOffset())
+      return BaseIndexOffset(LN->getOperand(1), SDValue(), LN->getOffset(),
+                             false);
+    return BaseIndexOffset(LN->getOperand(1), SDValue(), false);
+  }
+  return BaseIndexOffset();
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+
+LLVM_DUMP_METHOD void BaseIndexOffset::dump() const {
+  print(dbgs());
+}
+
+void BaseIndexOffset::print(raw_ostream& OS) const {
+  OS << "BaseIndexOffset base=[";
+  Base->print(OS);
+  OS << "] index=[";
+  if (Index)
+    Index->print(OS);
+  OS << "] offset=" << Offset;
+}
+
+#endif