[libc-commits] [libc] 1484e0f - [libc] Use CMAKE_CROSSCOMPILING_EMULATOR instead searching for `llvm-gpu-loader' (#189417)
via libc-commits
libc-commits at lists.llvm.org
Fri Apr 3 07:58:12 PDT 2026
Author: Joseph Huber
Date: 2026-04-03T09:58:04-05:00
New Revision: 1484e0f16a14421de6fa46a5425f7b07da9eeaac
URL: https://github.com/llvm/llvm-project/commit/1484e0f16a14421de6fa46a5425f7b07da9eeaac
DIFF: https://github.com/llvm/llvm-project/commit/1484e0f16a14421de6fa46a5425f7b07da9eeaac.diff
LOG: [libc] Use CMAKE_CROSSCOMPILING_EMULATOR instead searching for `llvm-gpu-loader' (#189417)
Summary:
We already handle this with other targets, we should be able to unify
the handling here.
Added:
Modified:
libc/CMakeLists.txt
libc/cmake/modules/LLVMLibCTestRules.cmake
libc/cmake/modules/prepare_libc_gpu_build.cmake
libc/docs/gpu/building.rst
libc/docs/gpu/testing.rst
libc/test/CMakeLists.txt
libc/test/lit.site.cfg.py.in
llvm/runtimes/CMakeLists.txt
Removed:
################################################################################
diff --git a/libc/CMakeLists.txt b/libc/CMakeLists.txt
index 5229940e76f8f..5b5fe981f2195 100644
--- a/libc/CMakeLists.txt
+++ b/libc/CMakeLists.txt
@@ -34,7 +34,6 @@ if (CMAKE_BUILD_TYPE STREQUAL "Debug")
add_definitions("-D_DEBUG")
endif()
-
# Default to C++17
set(CMAKE_CXX_STANDARD 17)
diff --git a/libc/cmake/modules/LLVMLibCTestRules.cmake b/libc/cmake/modules/LLVMLibCTestRules.cmake
index 11773fc78bd4b..6b69f5ca1f3fe 100644
--- a/libc/cmake/modules/LLVMLibCTestRules.cmake
+++ b/libc/cmake/modules/LLVMLibCTestRules.cmake
@@ -643,12 +643,6 @@ function(add_integration_test test_name)
libc.test.IntegrationTest.test
${INTEGRATION_TEST_DEPENDS})
- # Tests on the GPU require an external loader utility to launch the kernel.
- if(TARGET libc.utils.gpu.loader)
- add_dependencies(${fq_build_target_name} libc.utils.gpu.loader)
- get_target_property(gpu_loader_exe libc.utils.gpu.loader "EXECUTABLE")
- endif()
-
# We have to use a separate var to store the command as a list because
# the COMMAND option of `add_custom_target` cannot handle empty vars in the
# command. For example, if INTEGRATION_TEST_ENV is empty, the actual
@@ -658,7 +652,6 @@ function(add_integration_test test_name)
set(test_cmd
${INTEGRATION_TEST_ENV}
$<$<BOOL:${LIBC_TARGET_ARCHITECTURE_IS_NVPTX}>:LIBOMPTARGET_STACK_SIZE=3072>
- $<$<BOOL:${LIBC_TARGET_OS_IS_GPU}>:${gpu_loader_exe}>
${CMAKE_CROSSCOMPILING_EMULATOR}
${INTEGRATION_TEST_LOADER_ARGS}
$<TARGET_FILE:${fq_build_target_name}> ${INTEGRATION_TEST_ARGS})
@@ -896,12 +889,6 @@ function(add_libc_hermetic test_name)
)
endif()
- # Tests on the GPU require an external loader utility to launch the kernel.
- if(TARGET libc.utils.gpu.loader)
- add_dependencies(${fq_build_target_name} libc.utils.gpu.loader)
- get_target_property(gpu_loader_exe libc.utils.gpu.loader "EXECUTABLE")
- endif()
-
if(NOT HERMETIC_TEST_NO_RUN_POSTBUILD)
if (LIBC_TEST_CMD)
# In the form of "<command> binary=@BINARY@", e.g. "qemu-system-arm -loader$<COMMA>file=@BINARY@"
@@ -910,7 +897,7 @@ function(add_libc_hermetic test_name)
else()
set(test_cmd ${HERMETIC_TEST_ENV}
$<$<BOOL:${LIBC_TARGET_ARCHITECTURE_IS_NVPTX}>:LIBOMPTARGET_STACK_SIZE=3072>
- $<$<BOOL:${LIBC_TARGET_OS_IS_GPU}>:${gpu_loader_exe}> ${CMAKE_CROSSCOMPILING_EMULATOR} ${HERMETIC_TEST_LOADER_ARGS}
+ ${CMAKE_CROSSCOMPILING_EMULATOR} ${HERMETIC_TEST_LOADER_ARGS}
$<TARGET_FILE:${fq_build_target_name}> ${HERMETIC_TEST_ARGS})
endif()
diff --git a/libc/cmake/modules/prepare_libc_gpu_build.cmake b/libc/cmake/modules/prepare_libc_gpu_build.cmake
index fcf0e38db81af..c87a1df926c85 100644
--- a/libc/cmake/modules/prepare_libc_gpu_build.cmake
+++ b/libc/cmake/modules/prepare_libc_gpu_build.cmake
@@ -66,24 +66,6 @@ else()
endif()
set(LIBC_GPU_TARGET_ARCHITECTURE "${gpu_test_architecture}")
-# Identify the GPU loader utility used to run tests.
-set(LIBC_GPU_LOADER_EXECUTABLE "" CACHE STRING "Executable for the GPU loader.")
-if(LIBC_GPU_LOADER_EXECUTABLE)
- set(gpu_loader_executable ${LIBC_GPU_LOADER_EXECUTABLE})
-else()
- find_program(gpu_loader_executable
- NAMES llvm-gpu-loader NO_DEFAULT_PATH
- PATHS ${LLVM_BINARY_DIR}/bin ${compiler_path})
-endif()
-if(NOT TARGET libc.utils.gpu.loader AND gpu_loader_executable)
- add_custom_target(libc.utils.gpu.loader)
- set_target_properties(
- libc.utils.gpu.loader
- PROPERTIES
- EXECUTABLE "${gpu_loader_executable}"
- )
-endif()
-
# The AMDGPU environment uses
diff erent code objects to encode the ABI for
# kernel calls and intrinsic functions. We want to expose this to conform to
# whatever the test suite was built to handle.
diff --git a/libc/docs/gpu/building.rst b/libc/docs/gpu/building.rst
index d80ad0c0ff540..b8f5e79a430e3 100644
--- a/libc/docs/gpu/building.rst
+++ b/libc/docs/gpu/building.rst
@@ -195,6 +195,7 @@ standard runtime build.
commonly run out of resources if this is not constrained so it is recommended
to keep it low. The default value is a single thread.
-**LIBC_GPU_LOADER_EXECUTABLE**:STRING
- Overrides the default loader used for running GPU tests. If this is not
- provided the standard one will be built.
+**CMAKE_CROSSCOMPILING_EMULATOR**:STRING
+ Overrides the default loader used for running GPU tests. This is set
+ automatically to ``llvm-gpu-loader`` for GPU runtime targets when building
+ via the runtimes build.
diff --git a/libc/docs/gpu/testing.rst b/libc/docs/gpu/testing.rst
index 4115e68e5225a..c34467346b798 100644
--- a/libc/docs/gpu/testing.rst
+++ b/libc/docs/gpu/testing.rst
@@ -94,7 +94,7 @@ Running tests
Tests will only be built and run if a GPU target architecture is set and the
corresponding loader utility was built. These can be overridden with the
-``LIBC_GPU_TEST_ARCHITECTURE`` and ``LIBC_GPU_LOADER_EXECUTABLE`` :ref:`CMake
+``LIBC_GPU_TEST_ARCHITECTURE`` and ``CMAKE_CROSSCOMPILING_EMULATOR`` :ref:`CMake
options <gpu_cmake_options>`. Once built, they can be run like any other tests.
The CMake target depends on how the library was built.
diff --git a/libc/test/CMakeLists.txt b/libc/test/CMakeLists.txt
index 60478739aced4..5a154008c1867 100644
--- a/libc/test/CMakeLists.txt
+++ b/libc/test/CMakeLists.txt
@@ -16,11 +16,6 @@ add_custom_target(libc-hermetic-tests-build)
add_custom_target(libc-integration-tests-build)
add_custom_target(libc_include_tests-build)
-# Resolve the GPU loader executable path for the lit site config.
-if(TARGET libc.utils.gpu.loader)
- get_target_property(LIBC_GPU_LOADER_EXECUTABLE libc.utils.gpu.loader "EXECUTABLE")
-endif()
-
# Configure the site config file for lit
configure_lit_site_cfg(
${LIBC_SOURCE_DIR}/test/lit.site.cfg.py.in
@@ -34,7 +29,7 @@ configure_lit_site_cfg(
"LLVM_LIBS_DIR"
"LIBC_SOURCE_DIR"
"LIBC_BUILD_DIR"
- "LIBC_GPU_LOADER_EXECUTABLE"
+ "CMAKE_CROSSCOMPILING_EMULATOR"
)
add_lit_testsuite(check-libc-lit
@@ -46,8 +41,8 @@ add_lit_testsuite(check-libc-lit
add_subdirectory(UnitTest)
if(LIBC_TARGET_OS_IS_GPU)
- if(NOT TARGET libc.utils.gpu.loader)
- message(WARNING "Cannot build libc GPU tests, missing loader.")
+ if(NOT CMAKE_CROSSCOMPILING_EMULATOR)
+ message(WARNING "Cannot build libc GPU tests, set CMAKE_CROSS_COMPILING_EMULATOR.")
return()
elseif(LIBC_GPU_TESTS_DISABLED)
message(WARNING "Cannot build libc GPU tests, missing target architecture.")
diff --git a/libc/test/lit.site.cfg.py.in b/libc/test/lit.site.cfg.py.in
index 7773bdfdf0e9c..7727f16956d73 100644
--- a/libc/test/lit.site.cfg.py.in
+++ b/libc/test/lit.site.cfg.py.in
@@ -8,11 +8,11 @@ config.llvm_tools_dir = lit_config.substitute(path(r"@LLVM_TOOLS_DIR@"))
config.libc_src_root = path(r"@LIBC_SOURCE_DIR@")
config.libc_obj_root = path(r"@LIBC_BUILD_DIR@")
config.libc_test_cmd = "@LIBC_TEST_CMD@"
-config.libc_gpu_loader = path(r"@LIBC_GPU_LOADER_EXECUTABLE@")
+config.libc_crosscompiling_emulator = path(r"@CMAKE_CROSSCOMPILING_EMULATOR@")
-# If running GPU tests and no explicit test command is set, use the GPU loader.
-if not config.libc_test_cmd and config.libc_gpu_loader:
- config.libc_test_cmd = config.libc_gpu_loader + " @BINARY@"
+# If no explicit test command is set, use the cross-compiling emulator.
+if not config.libc_test_cmd and config.libc_crosscompiling_emulator:
+ config.libc_test_cmd = config.libc_crosscompiling_emulator + " @BINARY@"
# Add libc's utils directory to the path so we can import the test format.
site.addsitedir(os.path.join(config.libc_src_root, "utils"))
diff --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
index c3e8df91d1be5..20c79a2c2e2ef 100644
--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
@@ -591,6 +591,12 @@ if(build_runtimes)
endforeach()
endif()
if(LLVM_LIBC_GPU_BUILD)
+ set(_gpu_loader "${LLVM_TOOLS_BINARY_DIR}/llvm-gpu-loader${CMAKE_EXECUTABLE_SUFFIX}")
+ foreach(name ${LLVM_RUNTIME_TARGETS})
+ if(name MATCHES "^(amdgcn|nvptx)")
+ set(RUNTIMES_${name}_CMAKE_CROSSCOMPILING_EMULATOR "${_gpu_loader}" CACHE STRING "")
+ endif()
+ endforeach()
list(APPEND extra_cmake_args "-DLLVM_LIBC_GPU_BUILD=ON")
if(TARGET llvm-offload-binary)
list(APPEND extra_deps llvm-offload-binary)
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