[PATCH] D45616: [X86] Lower _mm[256|512]_cmp[.]_mask intrinsics to native llvm IR

Nikita Astafev via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Wed Nov 7 11:14:17 PST 2018

nastafev added a comment.

Hello. It seems you were well aware that you are changing the semantics of FP operation here by ignoring the signaling/quiet portion of the immediate. But what shall the user do now? There was no way to force quiet FP comparison behavior in C language, so intrinsics and reliance on quiet compare (and SAE bit in AVX512) were natural way of forcing it. And now you are taking them out. Is there a switch that could prevent this optimization? I think it could be more tolerable if you only did this under fast-math.

  rC Clang


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