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

Shilei Tian via Openmp-commits openmp-commits at lists.llvm.org
Sat Jun 1 21:14:38 PDT 2024


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

>From 497e3225f216b23a27cd64a2fd952bfbe07f0875 Mon Sep 17 00:00:00 2001
From: Shilei Tian <i at tianshilei.me>
Date: Sun, 2 Jun 2024 00:13:59 -0400
Subject: [PATCH] Reapply "[OpenMP][OMPX] Add shfl_down_sync (#93311)"

---
 offload/DeviceRTL/include/Utils.h             |  2 +
 offload/DeviceRTL/src/Mapping.cpp             | 24 ++++++-
 offload/DeviceRTL/src/Utils.cpp               | 15 ++--
 .../offloading/ompx_bare_shfl_down_sync.cpp   | 71 +++++++++++++++++++
 openmp/runtime/src/include/ompx.h.var         | 68 +++++++++++++++---
 5 files changed, 166 insertions(+), 14 deletions(-)
 create mode 100644 offload/test/offloading/ompx_bare_shfl_down_sync.cpp

diff --git a/offload/DeviceRTL/include/Utils.h b/offload/DeviceRTL/include/Utils.h
index d43b7f5c95de1..82e2397b5958b 100644
--- a/offload/DeviceRTL/include/Utils.h
+++ b/offload/DeviceRTL/include/Utils.h
@@ -25,6 +25,8 @@ int32_t shuffle(uint64_t Mask, int32_t Var, int32_t SrcLane);
 
 int32_t shuffleDown(uint64_t Mask, int32_t Var, uint32_t Delta, int32_t Width);
 
+int64_t shuffleDown(uint64_t Mask, int64_t Var, uint32_t Delta, int32_t Width);
+
 uint64_t ballotSync(uint64_t Mask, int32_t Pred);
 
 /// Return \p LowBits and \p HighBits packed into a single 64 bit value.
diff --git a/offload/DeviceRTL/src/Mapping.cpp b/offload/DeviceRTL/src/Mapping.cpp
index 4f39d2a299ee6..c1ce878746a69 100644
--- a/offload/DeviceRTL/src/Mapping.cpp
+++ b/offload/DeviceRTL/src/Mapping.cpp
@@ -364,8 +364,30 @@ _TGT_KERNEL_LANGUAGE(block_id, getBlockIdInKernel)
 _TGT_KERNEL_LANGUAGE(block_dim, getNumberOfThreadsInBlock)
 _TGT_KERNEL_LANGUAGE(grid_dim, getNumberOfBlocksInKernel)
 
-extern "C" uint64_t ompx_ballot_sync(uint64_t mask, int pred) {
+extern "C" {
+uint64_t ompx_ballot_sync(uint64_t mask, int pred) {
   return utils::ballotSync(mask, pred);
 }
 
+int ompx_shfl_down_sync_i(uint64_t mask, int var, unsigned delta, int width) {
+  return utils::shuffleDown(mask, var, delta, width);
+}
+
+float ompx_shfl_down_sync_f(uint64_t mask, float var, unsigned delta,
+                            int width) {
+  return utils::convertViaPun<float>(utils::shuffleDown(
+      mask, utils::convertViaPun<int32_t>(var), delta, width));
+}
+
+long ompx_shfl_down_sync_l(uint64_t mask, long var, unsigned delta, int width) {
+  return utils::shuffleDown(mask, var, delta, width);
+}
+
+double ompx_shfl_down_sync_d(uint64_t mask, double var, unsigned delta,
+                             int width) {
+  return utils::convertViaPun<double>(utils::shuffleDown(
+      mask, utils::convertViaPun<int64_t>(var), delta, width));
+}
+}
+
 #pragma omp end declare target
diff --git a/offload/DeviceRTL/src/Utils.cpp b/offload/DeviceRTL/src/Utils.cpp
index 606e3bec0d33c..53cc803234867 100644
--- a/offload/DeviceRTL/src/Utils.cpp
+++ b/offload/DeviceRTL/src/Utils.cpp
@@ -113,6 +113,15 @@ int32_t utils::shuffleDown(uint64_t Mask, int32_t Var, uint32_t Delta,
   return impl::shuffleDown(Mask, Var, Delta, Width);
 }
 
+int64_t utils::shuffleDown(uint64_t Mask, int64_t Var, uint32_t Delta,
+                           int32_t Width) {
+  uint32_t Lo, Hi;
+  utils::unpack(Var, Lo, Hi);
+  Hi = impl::shuffleDown(Mask, Hi, Delta, Width);
+  Lo = impl::shuffleDown(Mask, Lo, Delta, Width);
+  return utils::pack(Lo, Hi);
+}
+
 uint64_t utils::ballotSync(uint64_t Mask, int32_t Pred) {
   return impl::ballotSync(Mask, Pred);
 }
@@ -125,11 +134,7 @@ int32_t __kmpc_shuffle_int32(int32_t Val, int16_t Delta, int16_t SrcLane) {
 }
 
 int64_t __kmpc_shuffle_int64(int64_t Val, int16_t Delta, int16_t Width) {
-  uint32_t lo, hi;
-  utils::unpack(Val, lo, hi);
-  hi = impl::shuffleDown(lanes::All, hi, Delta, Width);
-  lo = impl::shuffleDown(lanes::All, lo, Delta, Width);
-  return utils::pack(lo, hi);
+  return utils::shuffleDown(lanes::All, Val, Delta, Width);
 }
 }
 
diff --git a/offload/test/offloading/ompx_bare_shfl_down_sync.cpp b/offload/test/offloading/ompx_bare_shfl_down_sync.cpp
new file mode 100644
index 0000000000000..4af321ccec33c
--- /dev/null
+++ b/offload/test/offloading/ompx_bare_shfl_down_sync.cpp
@@ -0,0 +1,71 @@
+// RUN: %libomptarget-compilexx-run-and-check-generic
+//
+// UNSUPPORTED: x86_64-pc-linux-gnu
+// UNSUPPORTED: x86_64-pc-linux-gnu-LTO
+// UNSUPPORTED: aarch64-unknown-linux-gnu
+// UNSUPPORTED: aarch64-unknown-linux-gnu-LTO
+// UNSUPPORTED: s390x-ibm-linux-gnu
+// UNSUPPORTED: s390x-ibm-linux-gnu-LTO
+
+#include <cassert>
+#include <cmath>
+#include <cstdint>
+#include <cstdio>
+#include <limits>
+#include <ompx.h>
+#include <type_traits>
+
+template <typename T, std::enable_if_t<std::is_integral<T>::value, bool> = true>
+bool equal(T LHS, T RHS) {
+  return LHS == RHS;
+}
+
+template <typename T,
+          std::enable_if_t<std::is_floating_point<T>::value, bool> = true>
+bool equal(T LHS, T RHS) {
+  return std::abs(LHS - RHS) < std::numeric_limits<T>::epsilon();
+}
+
+template <typename T> void test() {
+  constexpr const int num_blocks = 1;
+  constexpr const int block_size = 256;
+  constexpr const int N = num_blocks * block_size;
+  T *data = new T[N];
+  int *res = new int[N];
+
+  for (int i = 0; i < N; ++i)
+    data[i] = i;
+
+#pragma omp target teams ompx_bare num_teams(num_blocks) thread_limit(block_size) \
+        map(to: data[0:N]) map(from: res[0:N])
+  {
+    int tid = ompx_thread_id_x();
+    data[tid] = ompx::shfl_down_sync(~0U, data[tid], 1);
+#ifdef __AMDGCN_WAVEFRONT_SIZE
+    int warp_size = __AMDGCN_WAVEFRONT_SIZE;
+#else
+    int warp_size = 32;
+#endif
+    if ((tid & (warp_size - 1)) != warp_size - 1)
+      res[tid] = equal(data[tid], static_cast<T>(tid + 1));
+    else
+      res[tid] = equal(data[tid], static_cast<T>(tid));
+  }
+
+  for (int i = 0; i < N; ++i)
+    assert(res[i]);
+
+  delete[] res;
+  delete[] data;
+}
+
+int main(int argc, char *argv[]) {
+  test<int32_t>();
+  test<int64_t>();
+  test<float>();
+  test<double>();
+  // CHECK: PASS
+  printf("PASS\n");
+
+  return 0;
+}
diff --git a/openmp/runtime/src/include/ompx.h.var b/openmp/runtime/src/include/ompx.h.var
index 19851880c3ac3..623f0b9c315bd 100644
--- a/openmp/runtime/src/include/ompx.h.var
+++ b/openmp/runtime/src/include/ompx.h.var
@@ -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
+#endif
+
 typedef unsigned long uint64_t;
 
 #ifdef __cplusplus
@@ -75,11 +81,11 @@ _TGT_KERNEL_LANGUAGE_HOST_IMPL_GRID_C(grid_dim, 1)
   static inline RETTY ompx_##NAME(ARGS) { BODY; }
 
 _TGT_KERNEL_LANGUAGE_HOST_IMPL_SYNC_C(void, sync_block, int Ordering,
-                                      _Pragma("omp barrier"));
+                                      _Pragma("omp barrier"))
 _TGT_KERNEL_LANGUAGE_HOST_IMPL_SYNC_C(void, sync_block_acq_rel, void,
-                                      ompx_sync_block(ompx_acq_rel));
+                                      ompx_sync_block(ompx_acq_rel))
 _TGT_KERNEL_LANGUAGE_HOST_IMPL_SYNC_C(void, sync_block_divergent, int Ordering,
-                                      ompx_sync_block(Ordering));
+                                      ompx_sync_block(Ordering))
 #undef _TGT_KERNEL_LANGUAGE_HOST_IMPL_SYNC_C
 ///}
 
@@ -87,6 +93,22 @@ static inline uint64_t ompx_ballot_sync(uint64_t mask, int pred) {
   __builtin_trap();
 }
 
+/// ompx_shfl_down_sync_{i,f,l,d}
+///{
+#define _TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC_HOST_IMPL(TYPE, TY)                \
+  static inline TYPE ompx_shfl_down_sync_##TY(uint64_t mask, TYPE var,         \
+                                              unsigned delta, int width) {     \
+    __builtin_trap();                                                          \
+  }
+
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC_HOST_IMPL(int, i)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC_HOST_IMPL(float, f)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC_HOST_IMPL(long, l)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC_HOST_IMPL(double, d)
+
+#undef _TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC_HOST_IMPL
+///}
+
 #pragma omp end declare variant
 
 /// ompx_{sync_block}_{,divergent}
@@ -94,9 +116,9 @@ static inline uint64_t ompx_ballot_sync(uint64_t mask, int pred) {
 #define _TGT_KERNEL_LANGUAGE_DECL_SYNC_C(RETTY, NAME, ARGS)         \
   RETTY ompx_##NAME(ARGS);
 
-_TGT_KERNEL_LANGUAGE_DECL_SYNC_C(void, sync_block, int Ordering);
-_TGT_KERNEL_LANGUAGE_DECL_SYNC_C(void, sync_block_acq_rel, void);
-_TGT_KERNEL_LANGUAGE_DECL_SYNC_C(void, sync_block_divergent, int Ordering);
+_TGT_KERNEL_LANGUAGE_DECL_SYNC_C(void, sync_block, int Ordering)
+_TGT_KERNEL_LANGUAGE_DECL_SYNC_C(void, sync_block_acq_rel, void)
+_TGT_KERNEL_LANGUAGE_DECL_SYNC_C(void, sync_block_divergent, int Ordering)
 #undef _TGT_KERNEL_LANGUAGE_DECL_SYNC_C
 ///}
 
@@ -117,6 +139,20 @@ _TGT_KERNEL_LANGUAGE_DECL_GRID_C(grid_dim)
 
 uint64_t ompx_ballot_sync(uint64_t mask, int pred);
 
+/// ompx_shfl_down_sync_{i,f,l,d}
+///{
+#define _TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(TYPE, TY)                          \
+  TYPE ompx_shfl_down_sync_##TY(uint64_t mask, TYPE var, unsigned delta,       \
+                                int width);
+
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(int, i)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(float, f)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(long, l)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(double, d)
+
+#undef _TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC
+///}
+
 #ifdef __cplusplus
 }
 #endif
@@ -162,9 +198,9 @@ _TGT_KERNEL_LANGUAGE_HOST_IMPL_GRID_CXX(grid_dim)
   }
 
 _TGT_KERNEL_LANGUAGE_HOST_IMPL_SYNC_CXX(void, sync_block, int Ordering = acc_rel,
-                                        Ordering);
+                                        Ordering)
 _TGT_KERNEL_LANGUAGE_HOST_IMPL_SYNC_CXX(void, sync_block_divergent,
-                                        int Ordering = acc_rel, Ordering);
+                                        int Ordering = acc_rel, Ordering)
 #undef _TGT_KERNEL_LANGUAGE_HOST_IMPL_SYNC_CXX
 ///}
 
@@ -172,6 +208,22 @@ static inline uint64_t ballot_sync(uint64_t mask, int pred) {
   return ompx_ballot_sync(mask, pred);
 }
 
+/// shfl_down_sync
+///{
+#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) {                 \
+    return ompx_shfl_down_sync_##TY(mask, var, delta, width);                  \
+  }
+
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(int, i)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(float, f)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(long, l)
+_TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC(double, d)
+
+#undef _TGT_KERNEL_LANGUAGE_SHFL_DOWN_SYNC
+///}
+
 } // namespace ompx
 #endif
 



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