[llvm] [OpenMP] Replace use of target address space with <gpuintrin.h> local (PR #126119)
Joseph Huber via llvm-commits
llvm-commits at lists.llvm.org
Thu Feb 6 12:08:24 PST 2025
https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/126119
Summary:
This definition is more portable since it defines the correct value for
the target. I got rid of the helper mostly because I think it's easy
enough to use now that it's a type and being explicit about what's
`undef` or `poison` is good.
>From 5c612ef3fe7e76155595bdd5de30a2cf0153de88 Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Thu, 6 Feb 2025 14:06:07 -0600
Subject: [PATCH] [OpenMP] Replace use of target address space with
<gpuintrin.h> local
Summary:
This definition is more portable since it defines the correct value for
the target. I got rid of the helper mostly because I think it's easy
enough to use now that it's a type and being explicit about what's
`undef` or `poison` is good.
---
offload/DeviceRTL/include/DeviceTypes.h | 14 +------------
offload/DeviceRTL/src/Configuration.cpp | 4 ++--
offload/DeviceRTL/src/Mapping.cpp | 2 +-
offload/DeviceRTL/src/Reduction.cpp | 24 +++++++++++------------
offload/DeviceRTL/src/State.cpp | 15 +++++++++-----
offload/DeviceRTL/src/Synchronization.cpp | 2 +-
offload/DeviceRTL/src/Workshare.cpp | 5 +++--
7 files changed, 30 insertions(+), 36 deletions(-)
diff --git a/offload/DeviceRTL/include/DeviceTypes.h b/offload/DeviceRTL/include/DeviceTypes.h
index 308109b0749f05b..395d72eafbf4054 100644
--- a/offload/DeviceRTL/include/DeviceTypes.h
+++ b/offload/DeviceRTL/include/DeviceTypes.h
@@ -12,6 +12,7 @@
#ifndef OMPTARGET_TYPES_H
#define OMPTARGET_TYPES_H
+#include <gpuintrin.h>
#include <stddef.h>
#include <stdint.h>
@@ -155,19 +156,6 @@ typedef enum omp_allocator_handle_t {
#define __PRAGMA(STR) _Pragma(#STR)
#define OMP_PRAGMA(STR) __PRAGMA(omp STR)
-#define SHARED(NAME) \
- [[clang::address_space(3)]] NAME [[clang::loader_uninitialized]];
-
-// TODO: clang should use address space 5 for omp_thread_mem_alloc, but right
-// now that's not the case.
-#define THREAD_LOCAL(NAME) \
- [[clang::address_space(5)]] NAME [[clang::loader_uninitialized]]
-
-// TODO: clang should use address space 4 for omp_const_mem_alloc, maybe it
-// does?
-#define CONSTANT(NAME) \
- [[clang::address_space(4)]] NAME [[clang::loader_uninitialized]]
-
///}
#endif
diff --git a/offload/DeviceRTL/src/Configuration.cpp b/offload/DeviceRTL/src/Configuration.cpp
index a2dfa4a02a09478..796e9ee254f3ac8 100644
--- a/offload/DeviceRTL/src/Configuration.cpp
+++ b/offload/DeviceRTL/src/Configuration.cpp
@@ -28,8 +28,8 @@ using namespace ompx;
// This variable should be visible to the plugin so we override the default
// hidden visibility.
[[gnu::used, gnu::retain, gnu::weak,
- gnu::visibility("protected")]] DeviceEnvironmentTy
- CONSTANT(__omp_rtl_device_environment);
+ gnu::visibility("protected")]] DeviceEnvironmentTy __gpu_constant
+ __omp_rtl_device_environment;
uint32_t config::getAssumeTeamsOversubscription() {
return __omp_rtl_assume_teams_oversubscription;
diff --git a/offload/DeviceRTL/src/Mapping.cpp b/offload/DeviceRTL/src/Mapping.cpp
index a0c0f6721a84cce..bce62ec9546bc6a 100644
--- a/offload/DeviceRTL/src/Mapping.cpp
+++ b/offload/DeviceRTL/src/Mapping.cpp
@@ -308,7 +308,7 @@ uint32_t mapping::getNumberOfProcessorElements() {
// TODO: This is a workaround for initialization coming from kernels outside of
// the TU. We will need to solve this more correctly in the future.
-[[gnu::weak]] int SHARED(IsSPMDMode);
+[[clang::loader_uninitialized]] [[gnu::weak]] int __gpu_local IsSPMDMode;
void mapping::init(bool IsSPMD) {
if (mapping::isInitialThreadInLevel0(IsSPMD))
diff --git a/offload/DeviceRTL/src/Reduction.cpp b/offload/DeviceRTL/src/Reduction.cpp
index 25f34005532f7c6..3b5f911451cb7fa 100644
--- a/offload/DeviceRTL/src/Reduction.cpp
+++ b/offload/DeviceRTL/src/Reduction.cpp
@@ -71,16 +71,16 @@ static int32_t nvptx_parallel_reduce_nowait(void *reduce_data,
if (NumThreads == 1)
return 1;
- //
- // This reduce function handles reduction within a team. It handles
- // parallel regions in both L1 and L2 parallelism levels. It also
- // supports Generic, SPMD, and NoOMP modes.
- //
- // 1. Reduce within a warp.
- // 2. Warp master copies value to warp 0 via shared memory.
- // 3. Warp 0 reduces to a single value.
- // 4. The reduced value is available in the thread that returns 1.
- //
+ //
+ // This reduce function handles reduction within a team. It handles
+ // parallel regions in both L1 and L2 parallelism levels. It also
+ // supports Generic, SPMD, and NoOMP modes.
+ //
+ // 1. Reduce within a warp.
+ // 2. Warp master copies value to warp 0 via shared memory.
+ // 3. Warp 0 reduces to a single value.
+ // 4. The reduced value is available in the thread that returns 1.
+ //
#if __has_builtin(__nvvm_reflect)
if (__nvvm_reflect("__CUDA_ARCH") >= 700) {
@@ -196,8 +196,8 @@ int32_t __kmpc_nvptx_teams_reduce_nowait_v2(
uint32_t NumThreads = omp_get_num_threads();
uint32_t TeamId = omp_get_team_num();
uint32_t NumTeams = omp_get_num_teams();
- static unsigned SHARED(Bound);
- static unsigned SHARED(ChunkTeamCount);
+ [[clang::loader_uninitialized]] static unsigned __gpu_local Bound;
+ [[clang::loader_uninitialized]] static unsigned __gpu_local ChunkTeamCount;
// Block progress for teams greater than the current upper
// limit. We always only allow a number of teams less or equal
diff --git a/offload/DeviceRTL/src/State.cpp b/offload/DeviceRTL/src/State.cpp
index 89edb4802198c9c..0981b33dfdd4dce 100644
--- a/offload/DeviceRTL/src/State.cpp
+++ b/offload/DeviceRTL/src/State.cpp
@@ -32,11 +32,13 @@ using namespace ompx;
[[clang::address_space(3)]] DynamicSharedBuffer[];
/// The kernel environment passed to the init method by the compiler.
-static KernelEnvironmentTy *SHARED(KernelEnvironmentPtr);
+[[clang::loader_uninitialized]] static KernelEnvironmentTy *__gpu_local
+ KernelEnvironmentPtr;
/// The kernel launch environment passed as argument to the kernel by the
/// runtime.
-static KernelLaunchEnvironmentTy *SHARED(KernelLaunchEnvironmentPtr);
+[[clang::loader_uninitialized]] static KernelLaunchEnvironmentTy *__gpu_local
+ KernelLaunchEnvironmentPtr;
///}
@@ -108,7 +110,8 @@ static_assert(state::SharedScratchpadSize / mapping::MaxThreadsPerTeam <= 256,
"Shared scratchpad of this size not supported yet.");
/// The allocation of a single shared memory scratchpad.
-static SharedMemorySmartStackTy SHARED(SharedMemorySmartStack);
+[[clang::loader_uninitialized]] static SharedMemorySmartStackTy __gpu_local
+ SharedMemorySmartStack;
void SharedMemorySmartStackTy::init(bool IsSPMD) {
Usage[mapping::getThreadIdInBlock()] = 0;
@@ -220,8 +223,10 @@ void state::TeamStateTy::assertEqual(TeamStateTy &Other) const {
ASSERT(HasThreadState == Other.HasThreadState, nullptr);
}
-state::TeamStateTy SHARED(ompx::state::TeamState);
-state::ThreadStateTy **SHARED(ompx::state::ThreadStates);
+[[clang::loader_uninitialized]] state::TeamStateTy __gpu_local
+ ompx::state::TeamState;
+[[clang::loader_uninitialized]] state::ThreadStateTy **__gpu_local
+ ompx::state::ThreadStates;
namespace {
diff --git a/offload/DeviceRTL/src/Synchronization.cpp b/offload/DeviceRTL/src/Synchronization.cpp
index a5090b96560c8bc..55d6d75dfa7e61c 100644
--- a/offload/DeviceRTL/src/Synchronization.cpp
+++ b/offload/DeviceRTL/src/Synchronization.cpp
@@ -69,7 +69,7 @@ uint32_t atomicInc(uint32_t *A, uint32_t V, atomic::OrderingTy Ordering,
}
}
-uint32_t SHARED(namedBarrierTracker);
+[[clang::loader_uninitialized]] uint32_t __gpu_local namedBarrierTracker;
void namedBarrierInit() {
// Don't have global ctors, and shared memory is not zero init
diff --git a/offload/DeviceRTL/src/Workshare.cpp b/offload/DeviceRTL/src/Workshare.cpp
index b1f037a11bddf1f..9e34b94fe4b208c 100644
--- a/offload/DeviceRTL/src/Workshare.cpp
+++ b/offload/DeviceRTL/src/Workshare.cpp
@@ -45,7 +45,7 @@ struct DynamicScheduleTracker {
#define LAST_CHUNK 2
// TODO: This variable is a hack inherited from the old runtime.
-static uint64_t SHARED(Cnt);
+[[clang::loader_uninitialized]] static uint64_t __gpu_local Cnt;
template <typename T, typename ST> struct omptarget_nvptx_LoopSupport {
////////////////////////////////////////////////////////////////////////////////
@@ -457,7 +457,8 @@ template <typename T, typename ST> struct omptarget_nvptx_LoopSupport {
//
// __kmpc_dispatch_deinit
//
-static DynamicScheduleTracker **SHARED(ThreadDST);
+[[clang::loader_uninitialized]] static DynamicScheduleTracker **__gpu_local
+ ThreadDST;
// Create a new DST, link the current one, and define the new as current.
static DynamicScheduleTracker *pushDST() {
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