[Openmp-commits] [openmp] [OpenMP] Remove declaration and usage of __AMDGCN_WAVEFRONT_SIZE (PR #143761)

[via Openmp-commits]

https://github.com/nicebert updated https://github.com/llvm/llvm-project/pull/143761

>From a8633717b6f5e7b5d914f5ed0b84839e6f3e1031 Mon Sep 17 00:00:00 2001
From: Nicole Aschenbrenner <nicole.aschenbrenner at amd.com>
Date: Wed, 11 Jun 2025 14:01:39 -0400
Subject: [PATCH 1/2] [OpenMP] Remove declaration and usage of
 __AMDGCN_WAVEFRONT_SIZE

Removes usage of __AMDGCN_WAVEFRONT_SIZE as compile time constant.
---
 openmp/runtime/src/include/ompx.h.var | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/openmp/runtime/src/include/ompx.h.var b/openmp/runtime/src/include/ompx.h.var
index 623f0b9c315bd..a6e8b4718f881 100644
--- a/openmp/runtime/src/include/ompx.h.var
+++ b/openmp/runtime/src/include/ompx.h.var
@@ -9,13 +9,21 @@
 #ifndef __OMPX_H
 #define __OMPX_H
 
-#ifdef __AMDGCN_WAVEFRONT_SIZE
-#define __WARP_SIZE __AMDGCN_WAVEFRONT_SIZE
-#else
-#define __WARP_SIZE 32
+#if (defined(__NVPTX__) || defined(__AMDGPU__))
+#include <gpuintrin.h>
+#define __OMPX_TARGET_IS_GPU
 #endif
 
 typedef unsigned long uint64_t;
+typedef unsigned int uint32_t;
+
+static inline uint32_t __warpSize(void) {
+  #ifdef __OMPX_TARGET_IS_GPU
+    return __gpu_num_lanes();
+  #else
+    __builtin_trap();
+  #endif
+}
 
 #ifdef __cplusplus
 extern "C" {
@@ -212,7 +220,7 @@ static inline uint64_t ballot_sync(uint64_t mask, int pred) {
 ///{
 #define _TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(TYPE, TY)                          \
   static inline TYPE shfl_down_sync(uint64_t mask, TYPE var, unsigned delta,   \
-                                    int width = __WARP_SIZE) {                 \
+                                    int width = __warpSize()) {                \
     return ompx_shfl_down_sync_##TY(mask, var, delta, width);                  \
   }
 

>From 321468ecd2ad042bab8c69a0f0948857debbc71b Mon Sep 17 00:00:00 2001
From: nicebert <110385235+nicebert at users.noreply.github.com>
Date: Fri, 13 Jun 2025 15:18:48 +0200
Subject: [PATCH 2/2] Update openmp/runtime/src/include/ompx.h.var

Removes whitespaces at start of line.

Co-authored-by: Shilei Tian <i at tianshilei.me>
---
 openmp/runtime/src/include/ompx.h.var | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/openmp/runtime/src/include/ompx.h.var b/openmp/runtime/src/include/ompx.h.var
index a6e8b4718f881..6884745f4240c 100644
--- a/openmp/runtime/src/include/ompx.h.var
+++ b/openmp/runtime/src/include/ompx.h.var
@@ -18,11 +18,11 @@ typedef unsigned long uint64_t;
 typedef unsigned int uint32_t;
 
 static inline uint32_t __warpSize(void) {
-  #ifdef __OMPX_TARGET_IS_GPU
-    return __gpu_num_lanes();
-  #else
-    __builtin_trap();
-  #endif
+#ifdef __OMPX_TARGET_IS_GPU
+  return __gpu_num_lanes();
+#else
+  __builtin_trap();
+#endif
 }
 
 #ifdef __cplusplus