[PATCH] D49561: AMDGPU: Try to make isKnownNeverSNan more accurate

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec added a comment.

>> 1. Should we care about sNaNs with FP exceptions disabled?
> 
> Yes. This has to work. The OpenCL conformance tests check for this

OK. Makes sense. Just maybe we need to tell llvm that we actually support exceptions, which should not necessarily mean we trap on them.

>> 4. UnsafeAlgebra includes NoNaNs and thus all of the above applies.
> 
> I do not agree with this. The per-instruction flags have decoupled the unsafe algebra properties from no-nans, and the per-function/global flags should follow suit.

OK, UnsafeAlgebra is probably not a right condition. FastMathFlags::isFast() definitely is.


https://reviews.llvm.org/D49561