[llvm] [Vectorizer] fix GEPs incorrectly marked as "inbounds" (PR #120730)

[Florian Mayer via llvm-commits]

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@@ -8344,10 +8344,10 @@ VPRecipeBuilder::tryToWidenMemory(Instruction *I, ArrayRef<VPValue *> Operands,
         Ptr->getUnderlyingValue()->stripPointerCasts());
     VPSingleDefRecipe *VectorPtr;
     if (Reverse)
+      // N.B. we deliberately do pass getGEPNoWrapFlags here, because this
+      // transform can invalidate `inbounds`.
       VectorPtr = new VPReverseVectorPointerRecipe(
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fmayer wrote:

yeah, sgtm. i had the same thought when i uploaded the diffs but then was gone for the holidays.

https://github.com/llvm/llvm-project/pull/120730