https://github.com/jhuber6 updated
https://github.com/llvm/llvm-project/pull/119091
>From 4c710e49eea97e542b97e0b5e78b7915acd32383 Mon Sep 17 00:00:00 2001
From: Joseph Huber <hube...@outlook.com>
Date: Sat, 7 Dec 2024 13:47:23 -0600
Subject: [PATCH 1/3] [OpenMP] Use generic IR for the OpenMP DeviceRTL
Summary:
We previously built this for every single architecture to deal with
incompatibility. This patch updates it to use the 'generic' IR that
`libc` and other projects use. Who knows if this will have any
side-effects, probably worth testing more but it passes the tests I
expect to pass on my side.
---
clang/lib/Driver/ToolChains/CommonArgs.cpp | 3 +-
clang/lib/Driver/ToolChains/Cuda.cpp | 1 -
offload/DeviceRTL/CMakeLists.txt | 70 ++++-------------
offload/DeviceRTL/src/Reduction.cpp | 89 +++++++++++-----------
4 files changed, 62 insertions(+), 101 deletions(-)
diff --git a/clang/lib/Driver/ToolChains/CommonArgs.cpp
b/clang/lib/Driver/ToolChains/CommonArgs.cpp
index 7d3d7f8f03c491..3dd90ecf8bca4c 100644
--- a/clang/lib/Driver/ToolChains/CommonArgs.cpp
+++ b/clang/lib/Driver/ToolChains/CommonArgs.cpp
@@ -2800,8 +2800,7 @@ void tools::addOpenMPDeviceRTL(const Driver &D,
: options::OPT_libomptarget_nvptx_bc_path_EQ;
StringRef ArchPrefix = Triple.isAMDGCN() ? "amdgpu" : "nvptx";
- std::string LibOmpTargetName =
- ("libomptarget-" + ArchPrefix + "-" + BitcodeSuffix + ".bc").str();
+ std::string LibOmpTargetName = ("libomptarget-" + ArchPrefix + ".bc").str();
// First check whether user specifies bc library
if (const Arg *A = DriverArgs.getLastArg(LibomptargetBCPathOpt)) {
diff --git a/clang/lib/Driver/ToolChains/Cuda.cpp
b/clang/lib/Driver/ToolChains/Cuda.cpp
index 102794829795da..214f1e5d83478f 100644
--- a/clang/lib/Driver/ToolChains/Cuda.cpp
+++ b/clang/lib/Driver/ToolChains/Cuda.cpp
@@ -851,7 +851,6 @@ void CudaToolChain::addClangTargetOptions(
HostTC.addClangTargetOptions(DriverArgs, CC1Args, DeviceOffloadingKind);
StringRef GpuArch = DriverArgs.getLastArgValue(options::OPT_march_EQ);
- assert(!GpuArch.empty() && "Must have an explicit GPU arch.");
assert((DeviceOffloadingKind == Action::OFK_OpenMP ||
DeviceOffloadingKind == Action::OFK_Cuda) &&
"Only OpenMP or CUDA offloading kinds are supported for NVIDIA
GPUs.");
diff --git a/offload/DeviceRTL/CMakeLists.txt b/offload/DeviceRTL/CMakeLists.txt
index 1bf3eb9da38aa1..cda633c41062b6 100644
--- a/offload/DeviceRTL/CMakeLists.txt
+++ b/offload/DeviceRTL/CMakeLists.txt
@@ -42,38 +42,6 @@ set(devicertl_base_directory ${CMAKE_CURRENT_SOURCE_DIR})
set(include_directory ${devicertl_base_directory}/include)
set(source_directory ${devicertl_base_directory}/src)
-set(all_amdgpu_architectures "gfx700;gfx701;gfx801;gfx803;gfx900;gfx902;gfx906"
-
"gfx908;gfx90a;gfx90c;gfx940;gfx941;gfx942;gfx950;gfx1010"
-
"gfx1012;gfx1030;gfx1031;gfx1032;gfx1033;gfx1034;gfx1035"
- "gfx1036;gfx1100;gfx1101;gfx1102;gfx1103;gfx1150"
- "gfx1151;gfx1152;gfx1153")
-set(all_nvptx_architectures "sm_35;sm_37;sm_50;sm_52;sm_53;sm_60;sm_61;sm_62"
- "sm_70;sm_72;sm_75;sm_80;sm_86;sm_87;sm_89;sm_90")
-set(all_gpu_architectures
- "${all_amdgpu_architectures};${all_nvptx_architectures}")
-
-set(LIBOMPTARGET_DEVICE_ARCHITECTURES "all" CACHE STRING
- "List of device architectures to be used to compile the OpenMP DeviceRTL.")
-
-if(LIBOMPTARGET_DEVICE_ARCHITECTURES STREQUAL "all")
- set(LIBOMPTARGET_DEVICE_ARCHITECTURES ${all_gpu_architectures})
-elseif(LIBOMPTARGET_DEVICE_ARCHITECTURES STREQUAL "amdgpu")
- set(LIBOMPTARGET_DEVICE_ARCHITECTURES ${all_amdgpu_architectures})
-elseif(LIBOMPTARGET_DEVICE_ARCHITECTURES STREQUAL "nvptx")
- set(LIBOMPTARGET_DEVICE_ARCHITECTURES ${all_nvptx_architectures})
-elseif(LIBOMPTARGET_DEVICE_ARCHITECTURES STREQUAL "auto" OR
- LIBOMPTARGET_DEVICE_ARCHITECTURES STREQUAL "native")
- if(NOT LIBOMPTARGET_NVPTX_ARCH AND NOT LIBOMPTARGET_AMDGPU_ARCH)
- message(FATAL_ERROR
- "Could not find 'amdgpu-arch' and 'nvptx-arch' tools required for
'auto'")
- elseif(NOT LIBOMPTARGET_FOUND_NVIDIA_GPU AND NOT
LIBOMPTARGET_FOUND_AMDGPU_GPU)
- message(FATAL_ERROR "No AMD or NVIDIA GPU found on the system when using
'auto'")
- endif()
- set(LIBOMPTARGET_DEVICE_ARCHITECTURES
-
"${LIBOMPTARGET_NVPTX_DETECTED_ARCH_LIST};${LIBOMPTARGET_AMDGPU_DETECTED_ARCH_LIST}")
-endif()
-list(REMOVE_DUPLICATES LIBOMPTARGET_DEVICE_ARCHITECTURES)
-
set(include_files
${include_directory}/Allocator.h
${include_directory}/Configuration.h
@@ -141,20 +109,21 @@ set(bc_flags -c -foffload-lto -std=c++17
-fvisibility=hidden
# first create an object target
add_library(omptarget.devicertl.all_objs OBJECT IMPORTED)
-function(compileDeviceRTLLibrary target_cpu target_name target_triple)
+function(compileDeviceRTLLibrary target_name target_triple)
set(target_bc_flags ${ARGN})
set(bc_files "")
foreach(src ${src_files})
get_filename_component(infile ${src} ABSOLUTE)
get_filename_component(outfile ${src} NAME)
- set(outfile "${outfile}-${target_cpu}.bc")
+ set(outfile "${outfile}-${target_name}.bc")
set(depfile "${outfile}.d")
add_custom_command(OUTPUT ${outfile}
COMMAND ${CLANG_TOOL}
${bc_flags}
- --offload-arch=${target_cpu}
+ -fopenmp-targets=${target_triple}
+ -Xopenmp-target=${target_triple} -march=
${target_bc_flags}
-MD -MF ${depfile}
${infile} -o ${outfile}
@@ -177,7 +146,7 @@ function(compileDeviceRTLLibrary target_cpu target_name
target_triple)
list(APPEND bc_files ${outfile})
endforeach()
- set(bclib_name "libomptarget-${target_name}-${target_cpu}.bc")
+ set(bclib_name "libomptarget-${target_name}.bc")
# Link to a bitcode library.
add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/linked_${bclib_name}
@@ -217,7 +186,7 @@ function(compileDeviceRTLLibrary target_cpu target_name
target_triple)
APPEND)
endif()
- set(bclib_target_name "omptarget-${target_name}-${target_cpu}-bc")
+ set(bclib_target_name "omptarget-${target_name}-bc")
add_custom_target(${bclib_target_name} DEPENDS
${CMAKE_CURRENT_BINARY_DIR}/${bclib_name})
# Copy library to destination.
@@ -239,7 +208,7 @@ function(compileDeviceRTLLibrary target_cpu target_name
target_triple)
# Package the bitcode in the bitcode and embed it in an ELF for the static
library
add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/packaged_${bclib_name}
COMMAND ${PACKAGER_TOOL} -o
${CMAKE_CURRENT_BINARY_DIR}/packaged_${bclib_name}
-
"--image=file=${CMAKE_CURRENT_BINARY_DIR}/${bclib_name},${target_feature},triple=${target_triple},arch=${target_cpu},kind=openmp"
+
"--image=file=${CMAKE_CURRENT_BINARY_DIR}/${bclib_name},${target_feature},triple=${target_triple},arch=generic,kind=openmp"
DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${bclib_name}
COMMENT "Packaging LLVM offloading binary ${bclib_name}.out"
)
@@ -249,14 +218,14 @@ function(compileDeviceRTLLibrary target_cpu target_name
target_triple)
APPEND)
endif()
- set(output_name
"${CMAKE_CURRENT_BINARY_DIR}/devicertl-${target_name}-${target_cpu}.o")
+ set(output_name "${CMAKE_CURRENT_BINARY_DIR}/devicertl-${target_name}.o")
add_custom_command(OUTPUT ${output_name}
COMMAND ${CLANG_TOOL} --std=c++17 -c -nostdlib
-Xclang
-fembed-offload-object=${CMAKE_CURRENT_BINARY_DIR}/packaged_${bclib_name}
-o ${output_name}
${source_directory}/Stub.cpp
DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/packaged_${bclib_name}
${source_directory}/Stub.cpp
- COMMENT "Embedding LLVM offloading binary in
devicertl-${target_name}-${target_cpu}.o"
+ COMMENT "Embedding LLVM offloading binary in devicertl-${target_name}.o"
VERBATIM
)
if(TARGET clang)
@@ -269,11 +238,11 @@ function(compileDeviceRTLLibrary target_cpu target_name
target_triple)
set_property(TARGET omptarget.devicertl.all_objs APPEND PROPERTY
IMPORTED_OBJECTS ${output_name})
if (CMAKE_EXPORT_COMPILE_COMMANDS)
- set(ide_target_name omptarget-ide-${target_name}-${target_cpu})
+ set(ide_target_name omptarget-ide-${target_name})
add_library(${ide_target_name} STATIC EXCLUDE_FROM_ALL ${src_files})
target_compile_options(${ide_target_name} PRIVATE
- -fopenmp --offload-arch=${target_cpu} -fopenmp-cuda-mode
- -mllvm -openmp-opt-disable
+ -fopenmp-targets=${target_triple} -Xopenmp-target=${target_triple}
-march=
+ -fopenmp -fopenmp-cuda-mode -mllvm -openmp-opt-disable
-foffload-lto -fvisibility=hidden --offload-device-only
-nocudalib -nogpulib -nogpuinc -nostdlibinc -Wno-unknown-cuda-version
)
@@ -288,18 +257,11 @@ function(compileDeviceRTLLibrary target_cpu target_name
target_triple)
endif()
endfunction()
-# Generate a Bitcode library for all the gpu architectures the user requested.
-add_custom_target(omptarget.devicertl.nvptx)
add_custom_target(omptarget.devicertl.amdgpu)
-foreach(gpu_arch ${LIBOMPTARGET_DEVICE_ARCHITECTURES})
- if("${gpu_arch}" IN_LIST all_amdgpu_architectures)
- compileDeviceRTLLibrary(${gpu_arch} amdgpu amdgcn-amd-amdhsa -Xclang
-mcode-object-version=none)
- elseif("${gpu_arch}" IN_LIST all_nvptx_architectures)
- compileDeviceRTLLibrary(${gpu_arch} nvptx nvptx64-nvidia-cuda
--cuda-feature=+ptx63)
- else()
- message(FATAL_ERROR "Unknown GPU architecture '${gpu_arch}'")
- endif()
-endforeach()
+compileDeviceRTLLibrary(amdgpu amdgcn-amd-amdhsa -Xclang
-mcode-object-version=none)
+
+add_custom_target(omptarget.devicertl.nvptx)
+compileDeviceRTLLibrary(nvptx nvptx64-nvidia-cuda --cuda-feature=+ptx63)
# Archive all the object files generated above into a static library
add_library(omptarget.devicertl STATIC)
diff --git a/offload/DeviceRTL/src/Reduction.cpp
b/offload/DeviceRTL/src/Reduction.cpp
index 57df159d3f28e5..d1aa9d3e474f71 100644
--- a/offload/DeviceRTL/src/Reduction.cpp
+++ b/offload/DeviceRTL/src/Reduction.cpp
@@ -44,7 +44,6 @@ void gpu_irregular_warp_reduce(void *reduce_data,
ShuffleReductFnTy shflFct,
}
}
-#if !defined(__CUDA_ARCH__) || __CUDA_ARCH__ < 700
static uint32_t gpu_irregular_simd_reduce(void *reduce_data,
ShuffleReductFnTy shflFct) {
uint32_t size, remote_id, physical_lane_id;
@@ -63,7 +62,6 @@ static uint32_t gpu_irregular_simd_reduce(void *reduce_data,
} while (logical_lane_id % 2 == 0 && size > 1);
return (logical_lane_id == 0);
}
-#endif
static int32_t nvptx_parallel_reduce_nowait(void *reduce_data,
ShuffleReductFnTy shflFct,
@@ -74,49 +72,53 @@ static int32_t nvptx_parallel_reduce_nowait(void
*reduce_data,
uint32_t NumThreads = omp_get_num_threads();
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.
- */
-
-#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ >= 700
- uint32_t WarpsNeeded =
- (NumThreads + mapping::getWarpSize() - 1) / mapping::getWarpSize();
- uint32_t WarpId = mapping::getWarpIdInBlock();
-
- // Volta execution model:
- // For the Generic execution mode a parallel region either has 1 thread and
- // beyond that, always a multiple of 32. For the SPMD execution mode we may
- // have any number of threads.
- if ((NumThreads % mapping::getWarpSize() == 0) || (WarpId < WarpsNeeded - 1))
- gpu_regular_warp_reduce(reduce_data, shflFct);
- else if (NumThreads > 1) // Only SPMD execution mode comes thru this case.
- gpu_irregular_warp_reduce(reduce_data, shflFct,
- /*LaneCount=*/NumThreads %
mapping::getWarpSize(),
- /*LaneId=*/mapping::getThreadIdInBlock() %
- mapping::getWarpSize());
- // When we have more than [mapping::getWarpSize()] number of threads
- // a block reduction is performed here.
//
- // Only L1 parallel region can enter this if condition.
- if (NumThreads > mapping::getWarpSize()) {
- // Gather all the reduced values from each warp
- // to the first warp.
- cpyFct(reduce_data, WarpsNeeded);
+ // 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 (WarpId == 0)
- gpu_irregular_warp_reduce(reduce_data, shflFct, WarpsNeeded,
- BlockThreadId);
+#if __has_builtin(__nvvm_reflect)
+ if (__nvvm_reflect("__CUDA_ARCH") >= 700) {
+ uint32_t WarpsNeeded =
+ (NumThreads + mapping::getWarpSize() - 1) / mapping::getWarpSize();
+ uint32_t WarpId = mapping::getWarpIdInBlock();
+
+ // Volta execution model:
+ // For the Generic execution mode a parallel region either has 1 thread and
+ // beyond that, always a multiple of 32. For the SPMD execution mode we may
+ // have any number of threads.
+ if ((NumThreads % mapping::getWarpSize() == 0) ||
+ (WarpId < WarpsNeeded - 1))
+ gpu_regular_warp_reduce(reduce_data, shflFct);
+ else if (NumThreads > 1) // Only SPMD execution mode comes thru this case.
+ gpu_irregular_warp_reduce(
+ reduce_data, shflFct,
+ /*LaneCount=*/NumThreads % mapping::getWarpSize(),
+ /*LaneId=*/mapping::getThreadIdInBlock() % mapping::getWarpSize());
+
+ // When we have more than [mapping::getWarpSize()] number of threads
+ // a block reduction is performed here.
+ //
+ // Only L1 parallel region can enter this if condition.
+ if (NumThreads > mapping::getWarpSize()) {
+ // Gather all the reduced values from each warp
+ // to the first warp.
+ cpyFct(reduce_data, WarpsNeeded);
+
+ if (WarpId == 0)
+ gpu_irregular_warp_reduce(reduce_data, shflFct, WarpsNeeded,
+ BlockThreadId);
+ }
+ return BlockThreadId == 0;
}
- return BlockThreadId == 0;
-#else
+#endif
__kmpc_impl_lanemask_t Liveness = mapping::activemask();
if (Liveness == lanes::All) // Full warp
gpu_regular_warp_reduce(reduce_data, shflFct);
@@ -150,10 +152,9 @@ static int32_t nvptx_parallel_reduce_nowait(void
*reduce_data,
return BlockThreadId == 0;
}
- // Get the OMP thread Id. This is different from BlockThreadId in the case of
- // an L2 parallel region.
+ // Get the OMP thread Id. This is different from BlockThreadId in the case
+ // of an L2 parallel region.
return BlockThreadId == 0;
-#endif // __CUDA_ARCH__ >= 700
}
uint32_t roundToWarpsize(uint32_t s) {
>From ae742d66d1c92d4ef95bbcafa05298fb72dcfa63 Mon Sep 17 00:00:00 2001
From: Joseph Huber <hube...@outlook.com>
Date: Sat, 7 Dec 2024 13:56:50 -0600
Subject: [PATCH 2/3] update with comment
---
offload/DeviceRTL/CMakeLists.txt | 1 +
offload/DeviceRTL/src/Reduction.cpp | 20 ++++++++++----------
2 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/offload/DeviceRTL/CMakeLists.txt b/offload/DeviceRTL/CMakeLists.txt
index cda633c41062b6..22940264f9b19a 100644
--- a/offload/DeviceRTL/CMakeLists.txt
+++ b/offload/DeviceRTL/CMakeLists.txt
@@ -119,6 +119,7 @@ function(compileDeviceRTLLibrary target_name target_triple)
set(outfile "${outfile}-${target_name}.bc")
set(depfile "${outfile}.d")
+ # Passing an empty CPU to -march= suppressed target specific metadata.
add_custom_command(OUTPUT ${outfile}
COMMAND ${CLANG_TOOL}
${bc_flags}
diff --git a/offload/DeviceRTL/src/Reduction.cpp
b/offload/DeviceRTL/src/Reduction.cpp
index d1aa9d3e474f71..d3b4528401953c 100644
--- a/offload/DeviceRTL/src/Reduction.cpp
+++ b/offload/DeviceRTL/src/Reduction.cpp
@@ -73,16 +73,16 @@ 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) {
>From f868bbfc0c724dbd985e13c4a9fbe1c66aafc46a Mon Sep 17 00:00:00 2001
From: Joseph Huber <hube...@outlook.com>
Date: Sat, 7 Dec 2024 14:04:55 -0600
Subject: [PATCH 3/3] release notes
---
clang/docs/ReleaseNotes.rst | 3 +++
openmp/docs/ReleaseNotes.rst | 7 +++++--
2 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 12d8ebf3251bc0..1b2bb3b98f0dc4 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1153,6 +1153,9 @@ OpenMP Support
- Added support for 'omp assume' directive.
- Added support for 'omp scope' directive.
- Added support for allocator-modifier in 'allocate' clause.
+- Changed the OpenMP DeviceRTL to use 'generic' IR. The
+ ``LIBOMPTARGET_DEVICE_ARCHITECTURES`` CMake argument is now unused and will
+ always build support for AMDGPU and NVPTX targets.
Improvements
^^^^^^^^^^^^
diff --git a/openmp/docs/ReleaseNotes.rst b/openmp/docs/ReleaseNotes.rst
index d4a4b1a99f7813..db594bd71d7e61 100644
--- a/openmp/docs/ReleaseNotes.rst
+++ b/openmp/docs/ReleaseNotes.rst
@@ -1,5 +1,4 @@
-===========================
-OpenMP 20.0.0 Release Notes
+
===========================
@@ -19,3 +18,7 @@ from the `LLVM releases web site
<https://llvm.org/releases/>`_.
Non-comprehensive list of changes in this release
=================================================
+
+- Changed the OpenMP DeviceRTL to use 'generic' IR. The
+ ``LIBOMPTARGET_DEVICE_ARCHITECTURES`` CMake argument is now unused and will
+ always build support for AMDGPU and NVPTX targets.
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