added cmake detection of the OpenBLAS library

- thanks to
  https://github.com/BVLC/caffe/blob/master/cmake/Modules/FindOpenBLAS.cmake
- added dedicated openblas test, which has the same testing source the same as for the blas test

modules/math/openblas.cmake

@@ -0,0 +1,76 @@
+#.rst:
+#
+# Find and link to OpenBLAS.
+#
+# Variables defined::
+#
+#   OpenBLAS_FOUND
+#   OpenBLAS_LIB
+#   OpenBLAS_INCLUDE_DIR
+#
+# autocmake.yml configuration::
+#
+#   docopt: "--openblas Find and link to OpenBLAS [default: False]."
+#   define: "'-DENABLE_OPENBLAS={0}'.format(arguments['--openblas'])"
+
+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})
+
+SET(OpenBLAS_FOUND ON)
+
+#    Check include files
+IF(NOT OpenBLAS_INCLUDE_DIR)
+    SET(OpenBLAS_FOUND OFF)
+    MESSAGE(STATUS "Could not find OpenBLAS include. Turning OpenBLAS_FOUND off")
+ENDIF()
+
+#    Check libraries
+IF(NOT OpenBLAS_LIB)
+    SET(OpenBLAS_FOUND OFF)
+    MESSAGE(STATUS "Could not find OpenBLAS lib. Turning OpenBLAS_FOUND off")
+ENDIF()
+
+IF (OpenBLAS_FOUND)
+  IF (NOT OpenBLAS_FIND_QUIETLY)
+    MESSAGE(STATUS "Found OpenBLAS libraries: ${OpenBLAS_LIB}")
+    MESSAGE(STATUS "Found OpenBLAS include: ${OpenBLAS_INCLUDE_DIR}")
+  ENDIF (NOT OpenBLAS_FIND_QUIETLY)
+ELSE (OpenBLAS_FOUND)
+  IF (OpenBLAS_FIND_REQUIRED)
+    MESSAGE(FATAL_ERROR "Could not find OpenBLAS")
+  ENDIF (OpenBLAS_FIND_REQUIRED)
+ENDIF (OpenBLAS_FOUND)
+
+MARK_AS_ADVANCED(
+    OpenBLAS_INCLUDE_DIR
+    OpenBLAS_LIB
+    OpenBLAS
+)

test/fc_openblas/cmake/autocmake.yml

@@ -0,0 +1,11 @@
+name: example
+min_cmake_version: 2.8
+modules:
+- fc:
+  - source: ../../../modules/fc.cmake
+- math:
+  - source: ../../../modules/math/openblas.cmake
+- default_build_paths:
+  - source: ../../../modules/default_build_paths.cmake
+- src:
+  - source: ../../../modules/src.cmake

test/fc_openblas/src/CMakeLists.txt

@@ -0,0 +1,6 @@
+if(OpenBLAS_FOUND)
+    add_executable(example example.f90)
+    target_link_libraries(example ${OpenBLAS_LIB})
+else()
+    message(FATAL_ERROR "OpenBLAS library not found")
+endif()

test/fc_openblas/src/example.f90

@@ -0,0 +1,45 @@
+program example
+
+   implicit none
+
+   integer, parameter :: n = 10
+
+   integer :: i, j
+   logical :: test_ok
+
+   real(8), allocatable :: a(:, :)
+   real(8), allocatable :: b(:, :)
+   real(8), allocatable :: c(:, :)
+
+   allocate(a(n, n))
+   allocate(b(n, n))
+   allocate(c(n, n))
+
+   a = 1.0d0
+   b = 2.0d0
+   c = 0.0d0
+
+   call dgemm('n', 'n', n, n, n, 1.0d0, a, n, b, n, 0.0d0, c, n)
+
+   test_ok = .true.
+
+   do i = 1, n
+      do j = 1, n
+         if (dabs(c(i, j) - 20.0d0) > tiny(0.0d0)) then
+            print *, 'ERROR: element', i, j, 'is', c(i, j)
+            test_ok = .false.
+         end if
+      end do
+   end do
+
+   deallocate(a)
+   deallocate(b)
+   deallocate(c)
+
+   if (test_ok) then
+      print *, 'PASSED'
+   else
+      print *, 'FAILED'
+   end if
+
+end program