[libomptarget] Refactor shfl_down_sync macro to inline function

Summary:
[libomptarget] Refactor shfl_down_sync macro to inline function
See also abandoned D66846, split into this diff and others.

Reviewers: jdoerfert, ABataev, grokos, ronlieb, gregrodgers

Subscribers: openmp-commits

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D66853

llvm-svn: 370146

openmp/libomptarget/deviceRTLs/nvptx/src/omptarget-nvptx.h

@@ -51,13 +51,9 @@
 #ifndef CUDA_VERSION
 #error CUDA_VERSION macro is undefined, something wrong with cuda.
 #elif CUDA_VERSION >= 9000
-#define __SHFL_DOWN_SYNC(mask, var, delta, width)                              \
-  __shfl_down_sync((mask), (var), (delta), (width))
 #define __ACTIVEMASK() __activemask()
 #define __SYNCWARP(Mask) __syncwarp(Mask)
 #else
-#define __SHFL_DOWN_SYNC(mask, var, delta, width)                              \
-  __shfl_down((var), (delta), (width))
 #define __ACTIVEMASK() __ballot(1)
 // In Cuda < 9.0 no need to sync threads in warps.
 #define __SYNCWARP(Mask)

openmp/libomptarget/deviceRTLs/nvptx/src/reduction.cu

@@ -15,6 +15,7 @@
 #include <stdio.h>
 
 #include "omptarget-nvptx.h"
+#include "target_impl.h"
 
 EXTERN
 void __kmpc_nvptx_end_reduce(int32_t global_tid) {}
@@ -23,14 +24,14 @@ EXTERN
 void __kmpc_nvptx_end_reduce_nowait(int32_t global_tid) {}
 
 EXTERN int32_t __kmpc_shuffle_int32(int32_t val, int16_t delta, int16_t size) {
-  return __SHFL_DOWN_SYNC(0xFFFFFFFF, val, delta, size);
+  return __kmpc_impl_shfl_down_sync(0xFFFFFFFF, val, delta, size);
 }
 
 EXTERN int64_t __kmpc_shuffle_int64(int64_t val, int16_t delta, int16_t size) {
    int lo, hi;
    asm volatile("mov.b64 {%0,%1}, %2;" : "=r"(lo), "=r"(hi) : "l"(val));
-   hi = __SHFL_DOWN_SYNC(0xFFFFFFFF, hi, delta, size);
-   lo = __SHFL_DOWN_SYNC(0xFFFFFFFF, lo, delta, size);
+   hi = __kmpc_impl_shfl_down_sync(0xFFFFFFFF, hi, delta, size);
+   lo = __kmpc_impl_shfl_down_sync(0xFFFFFFFF, lo, delta, size);
    asm volatile("mov.b64 %0, {%1,%2};" : "=l"(val) : "r"(lo), "r"(hi));
    return val;
 }

openmp/libomptarget/deviceRTLs/nvptx/src/target_impl.h

@@ -43,13 +43,23 @@ INLINE int __kmpc_impl_popc(uint32_t x) { return __popc(x); }
 #endif
 
 // In Cuda 9.0, the *_sync() version takes an extra argument 'mask'.
+
 INLINE int32_t __kmpc_impl_shfl_sync(__kmpc_impl_lanemask_t Mask, int32_t Var,
                                      int32_t SrcLane) {
 #if CUDA_VERSION >= 9000
   return __shfl_sync(Mask, Var, SrcLane);
 #else
   return __shfl(Var, SrcLane);
 #endif // CUDA_VERSION
+
+INLINE int32_t __kmpc_impl_shfl_down_sync(__kmpc_impl_lanemask_t Mask,
+                                          int32_t Var, uint32_t Delta,
+                                          int32_t Width) {
+#if CUDA_VERSION >= 9000
+  return __shfl_down_sync(Mask, Var, Delta, Width);
+#else
+  return __shfl_down(Var, Delta, Width);
+#endif // CUDA_VERSION
 }
 
 INLINE void __kmpc_impl_syncwarp(int32_t Mask) { __SYNCWARP(Mask); }