[PATCH] D40150: [LibCallSimplifier] fix pow(x, 0.5) -> sqrt() transforms

[Sanjay Patel via Phabricator via llvm-commits]

spatel created this revision.
Herald added a subscriber: mcrosier.

This would be a lot simpler if we could disregard errno when we have relaxed FP math, but I'm assuming it's possible to do something like '-ffast-math -fmath-errno' and still expect errno to be set for domain errors?

As the first test shows, we could transform an llvm intrinsic into a libcall which could then set errno, so that's just wrong...unless I'm not seeing some loophole. The second test diff is a phantom change (same output as before), but I've updated the CHECK lines to highlight that we get that case right on purpose now.


https://reviews.llvm.org/D40150

Files:
  include/llvm/Transforms/Utils/SimplifyLibCalls.h
  lib/Transforms/Utils/SimplifyLibCalls.cpp
  test/Transforms/InstCombine/pow-sqrt.ll

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