c29_为Eigen库使能向量化

​​代码在git​​

设置编译参数，这里是检查编译环境参数

#使用check_cxx_compiler_flag　前，必须　include(CheckCXXCompilerFlag)
include(CheckCXXCompilerFlag)
check_cxx_compiler_flag("-march=native" _march_native_works)
check_cxx_compiler_flag("-xHost" _xhost_works)
message("_march_native_works: ${_march_native_works}")

输出结构是_march_native_works: 1

_march_native_works: 1

cmake_minimum_required(VERSION 3.5 FATAL_ERROR)

project(recipe-06 LANGUAGES CXX)

### 设置c++ 版本
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_EXTENSIONS OFF)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

### 使用　Eigen3
find_package(Eigen3 3.3 REQUIRED CONFIG)

#使用check_cxx_compiler_flag　前，必须　include(CheckCXXCompilerFlag)
include(CheckCXXCompilerFlag)
check_cxx_compiler_flag("-march=native" _march_native_works)
check_cxx_compiler_flag("-xHost" _xhost_works)
message("_march_native_works: ${_march_native_works}")

set(_CXX_FLAGS)

if(_march_native_works)
  message(STATUS "Using processor's vector instructions (-march=native compiler flag set)")
  set(_CXX_FLAGS "-march=native")
elseif(_xhost_works)
  message(STATUS "Using processor's vector instructions (-xHost compiler flag set)")
  set(_CXX_FLAGS "-xHost")
else()
  message(STATUS "No suitable compiler flag found for vectorization")
endif()

add_executable(linear-algebra-unoptimized linear-algebra.cpp)

target_link_libraries(linear-algebra-unoptimized
  PRIVATE
    Eigen3::Eigen
  )

add_executable(linear-algebra linear-algebra.cpp)

target_compile_options(linear-algebra
  PRIVATE
    ${_CXX_FLAGS}
  )

target_link_libraries(linear-algebra
  PRIVATE
    Eigen3::Eigen
  )