[libclc] Base the build around `add_sources` instead of source list (#197034) Summary: The current build uses a curated + deduplicated source list. This PR seeks to simplify this a little bit and canonicalize the behavior. Now we create the target up-front, `clc` and `opencl`. We add the directories which add sources to this target. We normalize the architecture to the variants. We always add target specific versions first. When we add sources we check if the file already exists and defer to the architecture specific one. This normalized the behavior, the directories are now laid out like this `clc/<arch>/<os>`. We normalize these to `amdgpu`, `nvptx`, and `spirv` respectively. We use the OS for the newly created vulkan target. We now control variants via checking if the directory for that exists, so it's nested more naturally. Hopefully this makes more sense, the goal is to exercise the fact that we have individual builds now. Previously this did not work because you could not add_subdirectory more than once. GitOrigin-RevId: 14bf8e76c021c200b6e37b9df996dbfc0b5dbd4e
libclc is an open source implementation of the library requirements of the OpenCL C programming language, as specified by the OpenCL 1.1 Specification. The following sections of the specification impose library requirements:
libclc is intended to be used with the Clang compiler's OpenCL frontend.
libclc is designed to be portable and extensible. To this end, it provides generic implementations of most library requirements, allowing the target to override the generic implementation at the granularity of individual functions.
libclc currently supports PTX, AMDGPU, SPIRV and CLSPV targets, but support for more targets is welcome.
libclc is built as part of an LLVM runtimes build.
Select the targets to build with LLVM_RUNTIME_TARGETS, and enable libclc for each selected target with the matching RUNTIMES_<target-triple>_LLVM_ENABLE_RUNTIMES cache entry.
cd llvm-project mkdir build cd build cmake ../llvm -G Ninja -DLLVM_ENABLE_PROJECTS="clang" -DCMAKE_BUILD_TYPE=Release \ -DRUNTIMES_amdgcn-amd-amdhsa-llvm_LLVM_ENABLE_RUNTIMES=libclc \ -DLLVM_RUNTIME_TARGETS="amdgcn-amd-amdhsa-llvm"
cmake ../llvm -G Ninja -DLLVM_ENABLE_PROJECTS="clang" -DCMAKE_BUILD_TYPE=Release \ -DRUNTIMES_nvptx64-nvidia-cuda_LLVM_ENABLE_RUNTIMES=libclc \ -DLLVM_RUNTIME_TARGETS="nvptx64-nvidia-cuda"
cmake ../llvm -G Ninja -DLLVM_ENABLE_PROJECTS="clang" -DCMAKE_BUILD_TYPE=Release \ -DRUNTIMES_spirv64-unknown-vulkan_LLVM_ENABLE_RUNTIMES=libclc \ -DLLVM_RUNTIME_TARGETS="spirv64-unknown-vulkan"
cmake ../llvm -G Ninja -DLLVM_ENABLE_PROJECTS="clang" -DCMAKE_BUILD_TYPE=Release \ -DRUNTIMES_spirv-mesa-mesa3d_LLVM_ENABLE_RUNTIMES=libclc \ -DRUNTIMES_spirv64-mesa-mesa3d_LLVM_ENABLE_RUNTIMES=libclc \ -DLLVM_RUNTIME_TARGETS="spirv-mesa-mesa3d;spirv64-mesa-mesa3d"
To build multiple targets, pass them as a semicolon-separated list in LLVM_RUNTIME_TARGETS and provide a matching RUNTIMES_<target-triple>_LLVM_ENABLE_RUNTIMES=libclc entry for each target.
ninja
ninja install
Note you can use the DESTDIR Makefile variable to do staged installs.
DESTDIR=/path/for/staged/install ninja install
libclc utilizes the LLVM testing infrastructure.
To execute all per-target tests for libclc.
ninja check-libclc
check-libclc is a top-level target that aggregates all per-target tests.
If you are working on a specific target, you can run tests for just that target triple:
ninja check-libclc-<target-triple>
Alternatively, you can run target-specific tests via the runtimes build by pointing to the target-specific build directory:
ninja -C runtimes/runtimes-<target-triple>-bins check-libclc
To build out of tree, or in other words, against an existing LLVM build or install:
CC=$(<path-to>/llvm-config --bindir)/clang cmake \ <path-to>/llvm-project/libclc/CMakeLists.txt -DCMAKE_BUILD_TYPE=Release \ -G Ninja -DLLVM_DIR=$(<path-to>/llvm-config --cmakedir) \ -DLLVM_RUNTIMES_TARGET=<target-triple> $ ninja
Then install as before.
In both cases, the LLVM used must include the targets you want libclc support for (AMDGPU and NVPTX are enabled in LLVM by default). Apart from SPIRV where you do not need an LLVM target but you do need the llvm-spirv tool available. Either build this in-tree, or place it in the directory pointed to by LLVM_TOOLS_BINARY_DIR.