[PATCH] D139312: ValueTracking: Teach CannotBeOrderedLessThanZero about copysign

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/test/Transforms/InstSimplify/floating-point-arithmetic.ll:964
+;
+  %sqrt = call ninf nnan float @llvm.sqrt.f32(float %sign)
+  %copysign = call float @llvm.copysign.f32(float %unknown, float %sqrt)
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spatel wrote:
> Something went wrong - this is a miscompile without 'nsz' on the sqrt (otherwise, it can return -0.0):
> https://alive2.llvm.org/ce/z/yqXQmQ
But this is being consumed by an fcmp - the sign of the zero shouldn't matter for the final result. Alive bug?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139312/new/

https://reviews.llvm.org/D139312