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CPU INFOrmation library

BSD (2 clause) License Linux/Mac build status Windows build status

cpuinfo is a library to detect essential for performance optimization information about host CPU.

Features

Examples

Log processor name:

cpuinfo_initialize();
printf("Running on %s CPU\n", cpuinfo_get_package(0)->name);

Detect if target is a 32-bit or 64-bit ARM system:

#if CPUINFO_ARCH_ARM || CPUINFO_ARCH_ARM64
    /* 32-bit ARM-specific code here */
#endif

Check if the host CPU supports ARM NEON

cpuinfo_initialize();
if (cpuinfo_has_arm_neon()) {
    neon_implementation(arguments);
}

Check if the host CPU supports x86 AVX

cpuinfo_initialize();
if (cpuinfo_has_x86_avx()) {
    avx_implementation(arguments);
}

Check if the thread runs on a Cortex-A53 core

cpuinfo_initialize();
switch (cpuinfo_get_current_core()->uarch) {
    case cpuinfo_uarch_cortex_a53:
        cortex_a53_implementation(arguments);
        break;
    default:
        generic_implementation(arguments);
        break;
}

Get the size of level 1 data cache on the fastest core in the processor (e.g. big core in big.LITTLE ARM systems):

cpuinfo_initialize();
const size_t l1_size = cpuinfo_get_processor(0)->cache.l1d->size;

Pin thread to cores sharing L2 cache with the current core (Linux or Android)

cpuinfo_initialize();
cpu_set_t cpu_set;
CPU_ZERO(&cpu_set);
const struct cpuinfo_cache* current_l2 = cpuinfo_get_current_processor()->cache.l2;
for (uint32_t i = 0; i < current_l2->processor_count; i++) {
    CPU_SET(cpuinfo_get_processor(current_l2->processor_start + i)->linux_id, &cpu_set);
}
pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpu_set);

Use via pkg-config

If you would like to provide your project's build environment with the necessary compiler and linker flags in a portable manner, the library by default when built enables CPUINFO_BUILD_PKG_CONFIG and will generate a pkg-config manifest (libcpuinfo.pc). Here are several examples of how to use it:

Command Line

If you used your distro's package manager to install the library, you can verify that it is available to your build environment like so:

$ pkg-config --cflags --libs libcpuinfo
-I/usr/include/x86_64-linux-gnu/ -L/lib/x86_64-linux-gnu/ -lcpuinfo

If you have installed the library from source into a non-standard prefix, pkg-config may need help finding it:

$ PKG_CONFIG_PATH="/home/me/projects/cpuinfo/prefix/lib/pkgconfig/:$PKG_CONFIG_PATH" pkg-config --cflags --libs libcpuinfo
-I/home/me/projects/cpuinfo/prefix/include -L/home/me/projects/cpuinfo/prefix/lib -lcpuinfo

GNU Autotools

To use with the GNU Autotools include the following snippet in your project's configure.ac:

# CPU INFOrmation library...
PKG_CHECK_MODULES(
    [libcpuinfo], [libcpuinfo], [],
    [AC_MSG_ERROR([libcpuinfo missing...])])
YOURPROJECT_CXXFLAGS="$YOURPROJECT_CXXFLAGS $libcpuinfo_CFLAGS"
YOURPROJECT_LIBS="$YOURPROJECT_LIBS $libcpuinfo_LIBS"

Meson

To use with Meson you just need to add dependency('libcpuinfo') as a dependency for your executable.

project(
    'MyCpuInfoProject',
    'cpp',
    meson_version: '>=0.55.0'
)

executable(
    'MyCpuInfoExecutable',
    sources: 'main.cpp',
    dependencies: dependency('libcpuinfo')
)

Bazel

This project can be built using Bazel.

You can also use this library as a dependency to your Bazel project. Add to the WORKSPACE file:

load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")

git_repository(
    name = "org_pytorch_cpuinfo",
    branch = "master",
    remote = "https://github.com/Vertexwahn/cpuinfo.git",
)

And to your BUILD file:

cc_binary(
    name = "cpuinfo_test",
    srcs = [
        # ...
    ],
    deps = [
        "@org_pytorch_cpuinfo//:cpuinfo",
    ],
)

CMake

To use with CMake use the FindPkgConfig module. Here is an example:

cmake_minimum_required(VERSION 3.6)
project("MyCpuInfoProject")

find_package(PkgConfig)
pkg_check_modules(CpuInfo REQUIRED IMPORTED_TARGET libcpuinfo)

add_executable(${PROJECT_NAME} main.cpp)
target_link_libraries(${PROJECT_NAME} PkgConfig::CpuInfo)

Makefile

To use within a vanilla makefile, you can call pkg-config directly to supply compiler and linker flags using shell substitution.

CFLAGS=-g3 -Wall -Wextra -Werror ...
LDFLAGS=-lfoo ...
...
CFLAGS+= $(pkg-config --cflags libcpuinfo)
LDFLAGS+= $(pkg-config --libs libcpuinfo)

Exposed information

Supported environments:

Methods