[PATCH] D118441: Preserve aliasing info during memory intrinsics lowering

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.
Herald added subscribers: mattd, gchakrabarti.


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Comment at: llvm/lib/Transforms/Utils/LowerMemIntrinsics.cpp:481
+    auto *DestSCEV = SE->getSCEV(Memcpy->getRawDest());
+    if (SE->isKnownPredicateAt(CmpInst::ICMP_NE, SrcSCEV, DestSCEV, Memcpy))
+      CanOverlap = false;
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Isn't this implied by the usual constraints of memcpy? The source and destination aren't allowed to overlap. Why does this need the SCEV check?


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  https://reviews.llvm.org/D118441/new/

https://reviews.llvm.org/D118441