[LLVM] Simplify GPU runtimes flag handling #159802
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Summary: The AMDGPU hack can be removed, and we no longer need to skip 90% of the `HandleLLVMOptions` if we work around NVPTX earlier. Simplifies the interface by removing duplicated logic and keeps the GPU targets from being weirdly divergent on some flags.
llvmbot
added
cmake
|
@llvm/pr-subscribers-libc Author: Joseph Huber (jhuber6) ChangesSummary: Full diff: https://github.com/llvm/llvm-project/pull/159802.diff 6 Files Affected:
diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
index 03db38fa4cdc1..cbd18d26c0b93 100644
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -418,11 +418,9 @@ macro(construct_compiler_rt_default_triple)
# Pass the necessary flags to make flag detection work.
if("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "amdgcn")
set(COMPILER_RT_GPU_BUILD ON)
- set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nogpulib")
elseif("${COMPILER_RT_DEFAULT_TARGET_ARCH}" MATCHES "nvptx")
set(COMPILER_RT_GPU_BUILD ON)
- set(CMAKE_REQUIRED_FLAGS
- "${CMAKE_REQUIRED_FLAGS} -flto -c -Wno-unused-command-line-argument")
+ set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -flto -c")
endif()
endif()
diff --git a/flang-rt/CMakeLists.txt b/flang-rt/CMakeLists.txt
index a45a66be6f833..cad39d0c71016 100644
--- a/flang-rt/CMakeLists.txt
+++ b/flang-rt/CMakeLists.txt
@@ -221,15 +221,6 @@ endif()
# System Introspection #
########################
-# The GPU targets require a few mandatory arguments to make the standard CMake
-# check flags happy.
-if ("${LLVM_RUNTIMES_TARGET}" MATCHES "^amdgcn")
- set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nogpulib")
-elseif ("${LLVM_RUNTIMES_TARGET}" MATCHES "^nvptx")
- set(CMAKE_REQUIRED_FLAGS
- "${CMAKE_REQUIRED_FLAGS} -flto -c -Wno-unused-command-line-argument")
-endif()
-
include(CheckCXXSymbolExists)
include(CheckCXXSourceCompiles)
check_cxx_symbol_exists(strerror_r string.h HAVE_STRERROR_R)
diff --git a/libc/cmake/modules/prepare_libc_gpu_build.cmake b/libc/cmake/modules/prepare_libc_gpu_build.cmake
index df1de1454c3eb..4d12a5917a56f 100644
--- a/libc/cmake/modules/prepare_libc_gpu_build.cmake
+++ b/libc/cmake/modules/prepare_libc_gpu_build.cmake
@@ -20,12 +20,6 @@ endif()
if(LIBC_TARGET_TRIPLE)
set(CMAKE_REQUIRED_FLAGS "--target=${LIBC_TARGET_TRIPLE}")
endif()
-if(LIBC_TARGET_ARCHITECTURE_IS_AMDGPU)
- set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nogpulib")
-elseif(LIBC_TARGET_ARCHITECTURE_IS_NVPTX)
- set(CMAKE_REQUIRED_FLAGS
- "${CMAKE_REQUIRED_FLAGS} -flto -c -Wno-unused-command-line-argument")
-endif()
# Optionally set up a job pool to limit the number of GPU tests run in parallel.
# This is sometimes necessary as running too many tests in parallel can cause
diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 24142c934b918..ba82f72df4f1e 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -144,12 +144,6 @@ if( LLVM_ENABLE_ASSERTIONS )
endif()
endif()
-# If we are targeting a GPU architecture in a runtimes build we want to ignore
-# all the standard flag handling.
-if(LLVM_RUNTIMES_GPU_BUILD)
- return()
-endif()
-
if(LLVM_ENABLE_EXPENSIVE_CHECKS)
# When LLVM_ENABLE_EXPENSIVE_CHECKS is ON, LLVM will intercept errors
# using assert(). An explicit check is performed here.
diff --git a/openmp/CMakeLists.txt b/openmp/CMakeLists.txt
index 1358e896d3cc5..a2b7e1054e02b 100644
--- a/openmp/CMakeLists.txt
+++ b/openmp/CMakeLists.txt
@@ -99,14 +99,6 @@ else()
set(CMAKE_CXX_EXTENSIONS NO)
endif()
-# Targeting the GPU directly requires a few flags to make CMake happy.
-if("${CMAKE_CXX_COMPILER_TARGET}" MATCHES "^amdgcn")
- set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -nogpulib")
-elseif("${CMAKE_CXX_COMPILER_TARGET}" MATCHES "^nvptx")
- set(CMAKE_REQUIRED_FLAGS
- "${CMAKE_REQUIRED_FLAGS} -flto -c -Wno-unused-command-line-argument")
-endif()
-
# Check and set up common compiler flags.
include(config-ix)
include(HandleOpenMPOptions)
diff --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
index 45a6517737b95..fac621a076aa4 100644
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -181,15 +181,14 @@ if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
endif()
endif()
+# The NVPTX target needs to override linking to pass compiler flag checks.
+if("${LLVM_RUNTIMES_TARGET}" MATCHES "^nvptx")
+ set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -flto -c")
+endif()
+
# Avoid checking whether the compiler is working.
set(LLVM_COMPILER_CHECKED ON)
-# This can be used to detect whether we're targeting a GPU architecture.
-if("${LLVM_RUNTIMES_TARGET}" MATCHES "^amdgcn" OR
- "${LLVM_RUNTIMES_TARGET}" MATCHES "^nvptx64")
- set(LLVM_RUNTIMES_GPU_BUILD ON)
-endif()
-
# Handle common options used by all runtimes.
include(AddLLVM)
include(HandleLLVMOptions)
|
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libcxx failure are unrelated |
michaelrj-google
approved these changes
Sep 19, 2025
|
LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/18/builds/21326 Here is the relevant piece of the build log for the reference |
YixingZhang007
pushed a commit
to YixingZhang007/llvm-project
that referenced
this pull request
Sep 27, 2025
Summary: The AMDGPU hack can be removed, and we no longer need to skip 90% of the `HandleLLVMOptions` if we work around NVPTX earlier. Simplifies the interface by removing duplicated logic and keeps the GPU targets from being weirdly divergent on some flags.
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Summary:
The AMDGPU hack can be removed, and we no longer need to skip 90% of the
HandleLLVMOptionsif we work around NVPTX earlier. Simplifies theinterface by removing duplicated logic and keeps the GPU targets from
being weirdly divergent on some flags.