Reputation: 960

Can CMake FindBLAS find OpenBLAS?

For demonstration, I use the 3-line CMakeLists.txt:

cmake_minimum_required(VERSION 2.8)
find_package( BLAS REQUIRED )
message( STATUS BLAS found: ${BLAS_LIBRARIES} )

I have cblas, ATLAS and OpenBLAS including developer packages installed on a Debian Linux system, plus CMake 2.8.9. When I call

cmake . -DBLA_VENDOR=ATLAS -DCMAKE_PREFIX_PATH=/usr/lib/atlas-base

the ATLAS library nicely appears found:

-- The C compiler identification is GNU 4.7.2
-- The CXX compiler identification is GNU 4.7.2
-- Check for working C compiler: /usr/bin/gcc
-- Check for working C compiler: /usr/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Looking for dgemm_
-- Looking for dgemm_ - found
-- A library with BLAS API found.
-- BLASfound:/usr/lib/atlas-base/libf77blas.so/usr/lib/atlas-base/libatlas.so
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp

Similarly, just

cmake .

will find /usr/lib/libblas.so for me. (I do not forget to remove the cache files before the second call.)

When I look into /usr/share/cmake-2.8/Modules/FindBLAS.cmake, I read as the permitted values of BLA_VENDOR:

##  Goto,ATLAS PhiPACK,CXML,DXML,SunPerf,SCSL,SGIMATH,IBMESSL,Intel10_32 (intel mkl v10 32 bit),Intel10_64lp (intel mkl v10 64 bit,lp thread model, lp64 model),
##  Intel10_64lp_seq (intel mkl v10 64 bit,sequential code, lp64 model),
##  Intel( older versions of mkl 32 and 64 bit), ACML,ACML_MP,ACML_GPU,Apple, NAS, Generic

That is, OpenBLAS is not listed. And a few random trials like

cmake . -DBLA_VENDOR=open -DCMAKE_PREFIX_PATH=/usr/lib/openblas-base

do not work either. Do I have to write my own FindBLAS in order to link to OpenBLAS with CMake?

Upvotes: 7

Answers (3)

Jayhello

Reputation: 6602

According to caffe, you can use it this way,below is my project structure:

FindOpenBLAS.cmake contents as below:

SET(Open_BLAS_INCLUDE_SEARCH_PATHS
    /usr/include
    /usr/include/openblas
    /usr/include/openblas-base
    /usr/local/include
    /usr/local/include/openblas
    /usr/local/include/openblas-base
    /opt/OpenBLAS/include
    $ENV{OpenBLAS_HOME}
    $ENV{OpenBLAS_HOME}/include
)

SET(Open_BLAS_LIB_SEARCH_PATHS
    /lib/
    /lib/openblas-base
    /lib64/
    /usr/lib
    /usr/lib/openblas-base
    /usr/lib64
    /usr/local/lib
    /usr/local/lib64
    /opt/OpenBLAS/lib
    $ENV{OpenBLAS}cd
    $ENV{OpenBLAS}/lib
    $ENV{OpenBLAS_HOME}
    $ENV{OpenBLAS_HOME}/lib
)

FIND_PATH(OpenBLAS_INCLUDE_DIR NAMES 
    cblas.h PATHS ${Open_BLAS_INCLUDE_SEARCH_PATHS}
)

FIND_LIBRARY(OpenBLAS_LIB NAMES 
    openblas PATHS ${Open_BLAS_LIB_SEARCH_PATHS}
)

message("OpenBLAS_INCLUDE_DIR: ${OpenBLAS_INCLUDE_DIR}, OpenBLAS_LIB: ${OpenBLAS_LIB}")

when use cmake it outputs :

The main CMakeLists.txt use the above FindOpenBLAS.cmake to find blas:

cmake_minimum_required(VERSION 3.5)
project(my_caffe)

set(CMAKE_CXX_STANDARD 11)


#dependence lib
set(CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)
find_package(OpenBLAS REQUIRED)

set(SOURCE_FILES main.cpp)
add_executable(my_caffe_test ${SOURCE_FILES})
# link blas
target_link_libraries(my_caffe_test
        ${OpenBLAS_LIB}
)

Upvotes: 2