We need to know which, if any, GPUs the user has on their system if we
want to be able to test the `libc` source code for the GPU. This patch
adds a basic check using the `amdgpu-arch` utility which is provided by
`clang`.
Checking for NVIDIA GPUs will be done later as this is a little
problematic right now. CMake provides a method that we use for Clang but
it will soon be deprecated, the replacement requires a newer CMake
version that we will have in the LLVM 17 branch in the future. CUDA also
provides `__nvcc_device_query` but it's very new so I'm not sure if we
should rely on it. I may introduce a new tool to do it similar to
`amdgpu-arch`.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D140422
message(FATAL_ERROR "LLVM_LIBC_FULL_BUILD must be enabled to build libc for "
"GPU.")
endif()
+
+# Identify any locally installed GPUs to use for testing.
+find_program(LIBC_AMDGPU_ARCH
+ NAMES amdgpu-arch
+ PATHS ${LLVM_BINARY_DIR}/bin /opt/rocm/llvm/bin/)
+if(LIBC_AMDGPU_ARCH)
+ execute_process(COMMAND ${LIBC_AMDGPU_ARCH}
+ OUTPUT_VARIABLE LIBC_AMDGPU_ARCH_OUTPUT
+ OUTPUT_STRIP_TRAILING_WHITESPACE)
+ string(FIND "${LIBC_AMDGPU_ARCH_OUTPUT}" "\n" first_arch_string)
+ string(SUBSTRING "${LIBC_AMDGPU_ARCH_OUTPUT}" 0 ${first_arch_string}
+ arch_string)
+ if(arch_string)
+ set(LIBC_GPU_TARGET_ARCHITECTURE_IS_AMDGPU TRUE)
+ set(LIBC_GPU_TARGET_TRIPLE "amdgcn-amd-amdhsa")
+ set(LIBC_GPU_TARGET_ARCHITECTURE "${arch_string}")
+ endif()
+endif()
+# TODO: Check for Nvidia GPUs.