Revert r354244 "[DAGCombiner] Eliminate dead stores to stack."

Breaks some bots.

llvm-svn: 354245

1 files changed, 0 insertions, 75 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
index c21ecfca13a..5666c1293e9 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp
@@ -79,81 +79,6 @@ bool BaseIndexOffset::equalBaseIndex(const BaseIndexOffset &Other,
   return false;
 }
 
-bool BaseIndexOffset::computeAliasing(const BaseIndexOffset &BasePtr0,
-                                      const int64_t NumBytes0,
-                                      const BaseIndexOffset &BasePtr1,
-                                      const int64_t NumBytes1,
-                                      const SelectionDAG &DAG, bool &IsAlias) {
-  if (!(BasePtr0.getBase().getNode() && BasePtr1.getBase().getNode()))
-    return false;
-  int64_t PtrDiff;
-  if (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(int64_t Size, const BaseIndexOffset &Other,
-                               int64_t OtherSize,
-                               const SelectionDAG &DAG) const {
-  int64_t Offset;
-  if (!equalBaseIndex(Other, DAG, Offset))
-    return false;
-  if (Offset >= 0) {
-    // Other is after *this:
-    // [-------*this---------]
-    //            [---Other--]
-    // ==Offset==>
-    return Offset + OtherSize <= Size;
-  }
-  // Other starts strictly before *this, it cannot be fully contained.
-  //    [-------*this---------]
-  // [--Other--]
-  return false;
-}
-
 /// Parses tree in Ptr for base, index, offset addresses.
 BaseIndexOffset BaseIndexOffset::match(const LSBaseSDNode *N,
                                        const SelectionDAG &DAG) {