[PATCH] D92203: [ConstantFold] Fold operations to poison if possible

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


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Comment at: llvm/test/Transforms/InstSimplify/ConstProp/poison.ll:114
+  %i4 = select i1 true, i8 poison, i8 %x
+  call void (...) @use(i1 %i1, i1 %i2, i8 %i3, i8 %i4, i8* getelementptr (i8, i8* poison, i64 1))
+  ret void
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aqjune wrote:
> The GEP had to be written as a constant expr because InstSimplify's SimplifyGEPInst wasn't calling llvm::ConstantFoldGetElementPtr.
It looks like it does invoke constant folding, but there is an earlier check for an undef base pointer, which also catches poison. When that is replaced to check poison first, it should work correctly.


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  https://reviews.llvm.org/D92203/new/

https://reviews.llvm.org/D92203