[Openmp-commits] [llvm] [openmp] Reapply "[OpenMP][OMPX] Add shfl_down_sync (#93311)" (PR #94139)

[Shilei Tian via Openmp-commits]

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@@ -9,6 +9,12 @@
 #ifndef __OMPX_H
 #define __OMPX_H
 
+#ifdef __AMDGCN_WAVEFRONT_SIZE
+#define __WARP_SIZE __AMDGCN_WAVEFRONT_SIZE
+#else
+#define __WARP_SIZE 32
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shiltian wrote:

For NVIDIA GPU it is 32. For AMDGPU, it is `__AMDGCN_WAVEFRONT_SIZE`.

https://github.com/llvm/llvm-project/pull/94139