[llvm-branch-commits] [llvm] InstCombine: Fold out nanless canonicalize pattern (PR #172998)

[Matt Arsenault via llvm-branch-commits]

arsenm wrote:

> I don't think your proof works: https://alive2.llvm.org/ce/z/T_dpgL See https://github.com/AliveToolkit/alive2/blob/20a8472b77ba8a1f0b172059d422a55cb4dff120/ir/instr.cpp#L1168-L1170 Looks like alive2 only respects the standard IEEE fp semantics.

I know I saw this catching issues with constant folding of canonicalize before. But this is broken even with IEEE because signaling nan quieting is still mandatory 


https://github.com/llvm/llvm-project/pull/172998