[PATCH] D104904: [OpenMP][AMDGCN] Initial math headers support

[Jon Chesterfield via Phabricator via cfe-commits]

JonChesterfield added inline comments.


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Comment at: clang/lib/Headers/__clang_hip_cmath.h:43
+__DEVICE__ __CONSTEXPR__ long abs(long __n) { return ::labs(__n); }
+__DEVICE__ __CONSTEXPR__ float fma(float __x, float __y, float __z) {
   return ::fmaf(__x, __y, __z);
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I'm pretty sure it's UB, no diagnostic req to call a non-constexpr function from a constexpr one. Nevertheless, it does presently seem to be working for nvptx clang so will probably work for amdgcn.

Strictly I think we're supposed to detect when called at compile time and call one implementation and otherwise call the library one, where weirdly it's ok for them to return different answers. I think there's a built-in we can call to select between the two.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D104904/new/

https://reviews.llvm.org/D104904