From cdc1a949c072c4ceaa3f94c1cdd84acea8ca7f5c Mon Sep 17 00:00:00 2001 From: Ross Burton Date: Mon, 21 Jul 2025 14:24:24 +0100 Subject: clang: improve LLVM target selection logic The GPU targets are incredibly slow to build, so if the DISTRO_FEATURES doesn't include opengl or vulkan assume that the user will not be using a GPU and disable them. Alternatively, a distribution could state that they'll only be using one of the backends, and set LLVM_TARGETS_GPU explicitly. On my build machine, disabling the GPU targets reduces the build time of clang-native from 21m to 16m. (From OE-Core rev: 2273a0685757421f39541a352d77b67e5ba604d3) Signed-off-by: Ross Burton Signed-off-by: Richard Purdie --- meta/recipes-devtools/clang/clang_git.bb | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/meta/recipes-devtools/clang/clang_git.bb b/meta/recipes-devtools/clang/clang_git.bb index a85626c45a..484f065a55 100644 --- a/meta/recipes-devtools/clang/clang_git.bb +++ b/meta/recipes-devtools/clang/clang_git.bb @@ -112,16 +112,18 @@ CLANG_DEFAULT_CXX_STDLIB;CLANG_DEFAULT_RTLIB;CLANG_DEFAULT_UNWINDLIB;\ CLANG_DEFAULT_OPENMP_RUNTIME;LLVM_ENABLE_PER_TARGET_RUNTIME_DIR;\ LLVM_BUILD_TOOLS;LLVM_USE_HOST_TOOLS;LLVM_CONFIG_PATH;LLVM_EXTERNAL_SPIRV_HEADERS_SOURCE_DIR;\ " + +# By default we build all the supported CPU architectures, and the GPU targets +# if the opengl or vulkan DISTRO_FEATURES are enabled. +# +# For target builds we default to building that specific architecture, BPF, and the GPU targets if required. # -# Default to build all OE-Core supported target arches (user overridable). -# Gennerally setting LLVM_TARGETS_TO_BUILD = "" in local.conf is ok in most simple situations -# where only one target architecture is needed along with just one build arch (usually X86) -# Core tier targets: -# AArch64;AMDGPU;ARM;AVR;BPF;Hexagon;Lanai;LoongArch;Mips;MSP430;NVPTX;PowerPC;RISCV;Sparc;SPIRV;SystemZ;VE;WebAssembly;X86;XCore -# Known experimental targets: ARC;CSKY;DirectX;M68k;Xtensa - -LLVM_TARGETS_TO_BUILD ?= "AMDGPU;AArch64;ARM;BPF;Mips;PowerPC;RISCV;X86;LoongArch;NVPTX;SPIRV" -LLVM_TARGETS_TO_BUILD:class-target ?= "${@get_clang_host_arch(bb, d)};AMDGPU;BPF;NVPTX;SPIRV" +# The available target list can be seen in the source code +# in the LLVM_ALL_TARGETS assignment: +# https://github.com/llvm/llvm-project/blob/main/llvm/CMakeLists.txt +LLVM_TARGETS_GPU ?= "${@bb.utils.contains_any('DISTRO_FEATURES', 'opengl vulkan', 'AMDGPU;NVPTX;SPIRV', '', d)}" +LLVM_TARGETS_TO_BUILD ?= "AArch64;ARM;BPF;Mips;PowerPC;RISCV;X86;LoongArch;${LLVM_TARGETS_GPU}" +LLVM_TARGETS_TO_BUILD:class-target ?= "${@get_clang_host_arch(bb, d)};BPF;${LLVM_TARGETS_GPU}" LLVM_EXPERIMENTAL_TARGETS_TO_BUILD ?= "" -- cgit v1.2.3-54-g00ecf