[cmake] clean up blas discovery (#47940)

Summary:
remove useless variable changes in blas discovery

Pull Request resolved: #47940

Reviewed By: malfet

Differential Revision: D25122228

Pulled By: walterddr

fbshipit-source-id: 12bc3ce9e4f89a72b6a92c10d14024e5941f4b96

cmake/Dependencies.cmake

@@ -107,6 +107,8 @@ if(CAFFE2_CMAKE_BUILDING_WITH_MAIN_REPO)
 endif()
 
 # ---[ BLAS
+
+# setting default preferred BLAS options if not already present.
 if(NOT INTERN_BUILD_MOBILE)
   set(BLAS "MKL" CACHE STRING "Selected BLAS library")
 else()
@@ -146,7 +148,6 @@ elseif(BLAS STREQUAL "MKL")
     set(CAFFE2_USE_MKL ON)
   else()
     message(WARNING "MKL could not be found. Defaulting to Eigen")
-    set(BLAS "Eigen" CACHE STRING "Selected BLAS library")
     set(CAFFE2_USE_EIGEN_FOR_BLAS ON)
     set(CAFFE2_USE_MKL OFF)
   endif()
@@ -173,9 +174,6 @@ if(NOT INTERN_BUILD_MOBILE)
     find_package(BLAS)
     if(NOT BLAS_FOUND)
       set(USE_BLAS 0)
-      set(BLAS "" CACHE STRING "Selected BLAS library")
-    else()
-      set(BLAS BLAS_INFO CACHE STRING "Selected BLAS library")
     endif()
   endif()
 
@@ -190,6 +188,11 @@ if(NOT INTERN_BUILD_MOBILE)
     endif()
     set(AT_MKL_ENABLED 1)
   endif()
+elseif(INTERN_USE_EIGEN_BLAS)
+  # Eigen BLAS for Mobile
+  set(USE_BLAS 1)
+  include(${CMAKE_CURRENT_LIST_DIR}/External/EigenBLAS.cmake)
+  list(APPEND Caffe2_DEPENDENCY_LIBS eigen_blas)
 endif()
 
 # ---[ Dependencies
@@ -285,13 +288,6 @@ set(CONFU_DEPENDENCIES_SOURCE_DIR ${PROJECT_BINARY_DIR}/confu-srcs
 set(CONFU_DEPENDENCIES_BINARY_DIR ${PROJECT_BINARY_DIR}/confu-deps
   CACHE PATH "Confu-style dependencies binary directory")
 
-# ---[ Eigen BLAS for Mobile
-if(INTERN_BUILD_MOBILE AND INTERN_USE_EIGEN_BLAS)
-  set(USE_BLAS 1)
-  include(${CMAKE_CURRENT_LIST_DIR}/External/EigenBLAS.cmake)
-  list(APPEND Caffe2_DEPENDENCY_LIBS eigen_blas)
-endif()
-
 # ---[ pthreadpool
 # Only add a dependency on pthreadpool if we are on a mobile build
 # or are building any of the libraries in the {Q/X}NNPACK family.

cmake/Modules/FindBLAS.cmake

@@ -83,7 +83,7 @@ MACRO(Check_Fortran_Libraries LIBRARIES _prefix _name _flags _list)
       check_fortran_function_exists(${_name} ${_prefix}${_combined_name}_WORKS)
     else (CMAKE_Fortran_COMPILER_WORKS)
       check_function_exists("${_name}_" ${_prefix}${_combined_name}_WORKS)
-    endif (CMAKE_Fortran_COMPILER_WORKS)
+    endif(CMAKE_Fortran_COMPILER_WORKS)
     set(CMAKE_REQUIRED_LIBRARIES)
     mark_as_advanced(${_prefix}${_combined_name}_WORKS)
     set(_libraries_work ${${_prefix}${_combined_name}_WORKS})
@@ -117,33 +117,46 @@ if((NOT BLAS_LIBRARIES)
   if (BLAS_LIBRARIES)
     set(BLAS_INFO "accelerate")
     set(BLAS_IS_ACCELERATE 1)
-  endif (BLAS_LIBRARIES)
+  endif(BLAS_LIBRARIES)
 endif()
 
 if((NOT BLAS_LIBRARIES)
     AND ((NOT WITH_BLAS) OR (WITH_BLAS STREQUAL "veclib")))
-  check_fortran_libraries(
-    BLAS_LIBRARIES
-    BLAS
-    sgemm
-    ""
-    "vecLib")
-  if (BLAS_LIBRARIES)
-    set(BLAS_INFO "veclib")
-  endif (BLAS_LIBRARIES)
+  FIND_PACKAGE(vecLib)
+  if(vecLib_FOUND)
+    SET(BLAS_INFO "veclib")
+  else()
+    check_fortran_libraries(
+      BLAS_LIBRARIES
+      BLAS
+      sgemm
+      ""
+      "vecLib")
+    if (BLAS_LIBRARIES)
+      set(BLAS_INFO "veclib")
+    endif(BLAS_LIBRARIES)
+  endif()
 endif()
 
 if((NOT BLAS_LIBRARIES)
     AND ((NOT WITH_BLAS) OR (WITH_BLAS STREQUAL "open")))
-  check_fortran_libraries(
-  BLAS_LIBRARIES
-  BLAS
-  sgemm
-  ""
-  "openblas")
-  if(BLAS_LIBRARIES)
-    set(BLAS_INFO "open")
-  endif(BLAS_LIBRARIES)
+  FIND_PACKAGE(OpenBLAS)
+  if(OpenBLAS_FOUND)
+    SET(BLAS_INFO "open")
+    SET(BLAS_LIBRARIES ${OpenBLAS_LIB})
+    SET(BLAS_INCLUDE_DIR ${OpenBLAS_INCLUDE_DIR})
+    SET(BLAS_VERSION ${OpenBLAS_VERSION})
+  else()
+    check_fortran_libraries(
+    BLAS_LIBRARIES
+    BLAS
+    sgemm
+    ""
+    "openblas")
+    if(BLAS_LIBRARIES)
+      set(BLAS_INFO "open")
+    endif(BLAS_LIBRARIES)
+  endif()
 endif()
 
 if((NOT BLAS_LIBRARIES)
@@ -182,7 +195,7 @@ if((NOT BLAS_LIBRARIES)
   "goto2;gfortran")
   if (BLAS_LIBRARIES)
     set(BLAS_INFO "goto")
-  endif (BLAS_LIBRARIES)
+  endif(BLAS_LIBRARIES)
 endif()
 
 if((NOT BLAS_LIBRARIES)
@@ -195,7 +208,7 @@ if((NOT BLAS_LIBRARIES)
   "goto2;gfortran;pthread")
   if (BLAS_LIBRARIES)
     set(BLAS_INFO "goto")
-  endif (BLAS_LIBRARIES)
+  endif(BLAS_LIBRARIES)
 endif()
 
 if((NOT BLAS_LIBRARIES)
@@ -208,7 +221,7 @@ if((NOT BLAS_LIBRARIES)
   "acml;gfortran")
   if (BLAS_LIBRARIES)
     set(BLAS_INFO "acml")
-  endif (BLAS_LIBRARIES)
+  endif(BLAS_LIBRARIES)
 endif()
 
 if((NOT BLAS_LIBRARIES)
@@ -222,21 +235,26 @@ if((NOT BLAS_LIBRARIES)
   "blis")
   if (BLAS_LIBRARIES)
     set(BLAS_INFO "FLAME")
-  endif (BLAS_LIBRARIES)
+  endif(BLAS_LIBRARIES)
 endif()
 
 # BLAS in ATLAS library? (http://math-atlas.sourceforge.net/)
 if((NOT BLAS_LIBRARIES)
     AND ((NOT WITH_BLAS) OR (WITH_BLAS STREQUAL "atlas")))
-  check_fortran_libraries(
-  BLAS_LIBRARIES
-  BLAS
-  sgemm
-  ""
-  "ptf77blas;atlas;gfortran")
-  if (BLAS_LIBRARIES)
-    set(BLAS_INFO "atlas")
-  endif (BLAS_LIBRARIES)
+  FIND_PACKAGE(Atlas)
+  if(Atlas_FOUND)
+    SET(BLAS_INFO "atlas")
+  else()
+    check_fortran_libraries(
+      BLAS_LIBRARIES
+      BLAS
+      sgemm
+      ""
+      "ptf77blas;atlas;gfortran")
+    if (BLAS_LIBRARIES)
+      set(BLAS_INFO "atlas")
+    endif(BLAS_LIBRARIES)
+  endif()
 endif()
 
 # Generic BLAS library?
@@ -250,7 +268,7 @@ if((NOT BLAS_LIBRARIES)
   "blas")
   if (BLAS_LIBRARIES)
     set(BLAS_INFO "generic")
-  endif (BLAS_LIBRARIES)
+  endif(BLAS_LIBRARIES)
 endif()
 
 # Determine if blas was compiled with the f2c conventions
@@ -287,7 +305,7 @@ int main() {
     SET(BLAS_F2C TRUE)
   ELSE (BLAS_F2C_DOUBLE_WORKS AND NOT BLAS_F2C_FLOAT_WORKS)
     SET(BLAS_F2C FALSE)
-  ENDIF (BLAS_F2C_DOUBLE_WORKS AND NOT BLAS_F2C_FLOAT_WORKS)
+  ENDIF(BLAS_F2C_DOUBLE_WORKS AND NOT BLAS_F2C_FLOAT_WORKS)
   CHECK_C_SOURCE_RUNS("
 #include <stdlib.h>
 #include <stdio.h>
@@ -303,7 +321,7 @@ int main() {
     SET(BLAS_USE_CBLAS_DOT TRUE)
   ELSE (BLAS_USE_CBLAS_DOT)
     SET(BLAS_USE_CBLAS_DOT FALSE)
-  ENDIF (BLAS_USE_CBLAS_DOT)
+  ENDIF(BLAS_USE_CBLAS_DOT)
   SET(CMAKE_REQUIRED_LIBRARIES)
 ENDIF(BLAS_LIBRARIES)
 
@@ -317,10 +335,10 @@ endif(BLAS_LIBRARIES)
 
 IF (NOT BLAS_FOUND AND BLAS_FIND_REQUIRED)
   message(FATAL_ERROR "Cannot find a library with BLAS API. Please specify library location.")
-ENDIF (NOT BLAS_FOUND AND BLAS_FIND_REQUIRED)
+ENDIF(NOT BLAS_FOUND AND BLAS_FIND_REQUIRED)
 IF(NOT BLAS_FIND_QUIETLY)
   IF(BLAS_FOUND)
-    MESSAGE(STATUS "Found a library with BLAS API (${BLAS_INFO}).")
+    MESSAGE(STATUS "Found a library with BLAS API (${BLAS_INFO}). Full path: (${BLAS_LIBRARIES})")
   ELSE(BLAS_FOUND)
     MESSAGE(STATUS "Cannot find a library with BLAS API. Not using BLAS.")
   ENDIF(BLAS_FOUND)