[llvm] bc0976e - [LAA] Strip non-inbounds offset in getPointerDiff() (NFC) (#118665)

[via llvm-commits]

Author: Nikita Popov
Date: 2024-12-10T13:05:34+01:00
New Revision: bc0976ed1f96c20546796d4aa18abf3acfc0850f

URL: https://github.com/llvm/llvm-project/commit/bc0976ed1f96c20546796d4aa18abf3acfc0850f
DIFF: https://github.com/llvm/llvm-project/commit/bc0976ed1f96c20546796d4aa18abf3acfc0850f.diff

LOG: [LAA] Strip non-inbounds offset in getPointerDiff() (NFC) (#118665)

I believe that this code doesn't care whether the offsets are known to
be inbounds a priori. For the same reason the change is not testable, as
the SCEV based fallback code will look through non-inbounds offsets
anyway. So make it clear that there is no special inbounds requirement
here.

Added: 
    

Modified: 
    llvm/lib/Analysis/LoopAccessAnalysis.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index 71582d5d86549b..2c75d5625cb66d 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1566,10 +1566,10 @@ std::optional<int> llvm::getPointersDiff(Type *ElemTyA, Value *PtrA,
   unsigned IdxWidth = DL.getIndexSizeInBits(ASA);
 
   APInt OffsetA(IdxWidth, 0), OffsetB(IdxWidth, 0);
-  const Value *PtrA1 =
-      PtrA->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetA);
-  const Value *PtrB1 =
-      PtrB->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetB);
+  const Value *PtrA1 = PtrA->stripAndAccumulateConstantOffsets(
+      DL, OffsetA, /*AllowNonInbounds=*/true);
+  const Value *PtrB1 = PtrB->stripAndAccumulateConstantOffsets(
+      DL, OffsetB, /*AllowNonInbounds=*/true);
 
   int Val;
   if (PtrA1 == PtrB1) {