[PATCH] D99424: [BasicAA] Be more careful with modulo ops on VariableGEPIndex.

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


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Comment at: llvm/test/Analysis/BasicAA/gep-modulo.ll:133
 ; CHECK-NEXT:    PartialAlias: [16 x i8]* %ptr, i8* %gep.3
-; CHECK-NEXT:    NoAlias:  i8* %gep.3, i8* %gep.idx
+; CHECK-NEXT:    MayAlias:  i8* %gep.3, i8* %gep.idx
 ;
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nikic wrote:
> This is an example of the case I have in mind: This can be NoAlias (https://alive2.llvm.org/ce/z/yYFAAz) even though the mul+sub can wrap. Despite the wrapping, we are still guaranteed that the power-of-2 part of the GCD still holds.
Eh, maybe I'm wrong here regarding the general case. I'll have to think about it more carefully.


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  https://reviews.llvm.org/D99424/new/

https://reviews.llvm.org/D99424