[Openmp-commits] [PATCH] D54967: [OPENMP][NVPTX]Basic support for reductions across the teams.

[Alexey Bataev via Phabricator via Openmp-commits]

ABataev created this revision.
ABataev added reviewers: gtbercea, kkwli0.
Herald added subscribers: jfb, guansong.

Added functions __kmpc_nvptx_teams_reduce_nowait_simple and
__kmpc_nvptx_teams_end_reduce_nowait_simple to implement basic support
for reductions across the teams.


Repository:
  rOMP OpenMP

https://reviews.llvm.org/D54967

Files:
  libomptarget/deviceRTLs/nvptx/src/interface.h
  libomptarget/deviceRTLs/nvptx/src/reduction.cu


Index: libomptarget/deviceRTLs/nvptx/src/reduction.cu
===================================================================
--- libomptarget/deviceRTLs/nvptx/src/reduction.cu
+++ libomptarget/deviceRTLs/nvptx/src/reduction.cu
@@ -430,3 +430,21 @@
                                    /*isSPMDExecutionMode=*/false,
                                    /*isRuntimeUninitialized=*/true);
 }
+
+EXTERN int32_t __kmpc_nvptx_teams_reduce_nowait_simple(kmp_Ident *loc,
+                                                       int32_t global_tid,
+                                                       kmp_CriticalName *crit) {
+  if (checkSPMDMode(loc) && GetThreadIdInBlock() != 0)
+    return 0;
+  // The master thread of the team actually does the reduction.
+  while (atomicCAS((uint32_t *)crit, 0, 1))
+    ;
+  return 1;
+}
+
+EXTERN void
+__kmpc_nvptx_teams_end_reduce_nowait_simple(kmp_Ident *loc, int32_t global_tid,
+                                            kmp_CriticalName *crit) {
+  (void)atomicExch((uint32_t *)crit, 0);
+}
+
Index: libomptarget/deviceRTLs/nvptx/src/interface.h
===================================================================
--- libomptarget/deviceRTLs/nvptx/src/interface.h
+++ libomptarget/deviceRTLs/nvptx/src/interface.h
@@ -419,6 +419,12 @@
     int32_t global_tid, int32_t num_vars, size_t reduce_size, void *reduce_data,
     kmp_ShuffleReductFctPtr shflFct, kmp_InterWarpCopyFctPtr cpyFct,
     kmp_CopyToScratchpadFctPtr sratchFct, kmp_LoadReduceFctPtr ldFct);
+EXTERN int32_t __kmpc_nvptx_teams_reduce_nowait_simple(kmp_Ident *loc,
+                                                       int32_t global_tid,
+                                                       kmp_CriticalName *crit);
+EXTERN void __kmpc_nvptx_teams_end_reduce_nowait_simple(kmp_Ident *loc,
+                                                        int32_t global_tid,
+                                                        kmp_CriticalName *crit);
 EXTERN int32_t __kmpc_shuffle_int32(int32_t val, int16_t delta, int16_t size);
 EXTERN int64_t __kmpc_shuffle_int64(int64_t val, int16_t delta, int16_t size);
 


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