openblas下載安裝與使用

openblas下載

• 官方地址
• zip文件
• tar文件

openblas安裝

直接執行

git clone https://github.com/xianyi/OpenBLAS.git
cd OpenBLAS
make
make PREFIX=/path/to/your/installation install

openblas使用

將相應的頭文件及庫文件考到相應的位置

cp ~/software/openblas/include/* ./include/
cp ~/software/openblas/lib/libopenblas.a ./lib/

cmake文件如下：

cmake_minimum_required (VERSION 2.6)
project (TEST)

set (TEST_VERSION 0.1)
 
set(CMAKE_BUILD_TYPE "Debug")
set(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g -ggdb -DDEBUG")
set(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -O3 -Wall")
  
set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/../bin)

aux_source_directory(${PROJECT_SOURCE_DIR}/src DIR_SRC)
 
include_directories(${PROJECT_SOURCE_DIR}/src)

include_directories(${PROJECT_SOURCE_DIR}/include)

link_directories(${PROJECT_SOURCE_DIR}/lib)
add_executable(main ${DIR_SRC})

target_link_libraries(main libopenblas.a)
target_link_libraries(main -lm)
target_link_libraries(main -lpthread)

注意最后多連接了兩個庫：

target_link_libraries(main -lm)
target_link_libraries(main -lpthread)

測試程序如下：

#include <cblas.h>
#include <stdio.h>

void main() {

    int i = 0;
    double A[6] = {1.0,2.0,1.0,-3.0,4.0,-1.0};         
    double B[6] = {1.0,2.0,1.0,-3.0,4.0,-1.0};  
    double C[9] = {.5,.5,.5,.5,.5,.5,.5,.5,.5}; 

    int M = 3; // row of A and C
    int N = 3; // col of B and C
    int K = 2; // col of A and row of B

    double alpha = 1.0;
    double beta = 0.0;

    cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, M, N, K, alpha, A, K, B, N, beta, C, N);

    for (i = 0; i < 9; i++) {
        printf("%lf ", C[i]);
    }
    printf("\n");
}

保存為main.c,放在文件夾src中，執行

mkdir build
cd build
cmake ..
make

生成執行文件在文件夾bin中。

接口說明

• 接口說明
  如果出現

/usr/bin/ld: 找不到 -lopenblas

則要在openblas的lib文件夾中找到libopenblas.a執行

sudo cp ./lib/libopenblas.a /usr/local/lib/