[PATCH] D93179: [X86] Convert fmin/fmax _mm_reduce_* intrinsics to emit llvm.reduction intrinsics (PR47506)

[Sanjay Patel via Phabricator via cfe-commits]

spatel added inline comments.


================
Comment at: clang/lib/Headers/avx512fintrin.h:9305
+ * 1. The elements are reassociable when using fadd/fmul intrinsics;
+ * 2. There's no nan and signed zero in the elements when using fmin/max
+ intrinsics;
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If I understand correctly, there's nothing preventing -0.0 or NaN values in these ops. But if either of those are present, then the result is potentially indeterminate.

For the LLVM intrinsic, we have this text in LangRef:
"The result will always be a number unless all elements of the vector are NaN. For a vector with minimum element magnitude 0.0 and containing both +0.0 and -0.0 elements, the sign of the result is unspecified."


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https://reviews.llvm.org/D93179