Added option to link against mkl_sequential (#1302)

dlib/CMakeLists.txt

@@ -140,6 +140,8 @@ if (NOT TARGET dlib)
       "Disable this if you don't want to use a LAPACK library" )
    set (DLIB_USE_CUDA_STR
       "Disable this if you don't want to use NVIDIA CUDA" )
+   set (DLIB_USE_MKL_SEQUENTIAL_STR
+      "Enable this if you have MKL installed and want to use the sequential version" )
    set (DLIB_PNG_SUPPORT_STR
       "Disable this if you don't want to link against libpng" )
    set (DLIB_GIF_SUPPORT_STR
@@ -162,6 +164,7 @@ if (NOT TARGET dlib)
    toggle_preprocessor_switch(DLIB_NO_GUI_SUPPORT)
    option(DLIB_ENABLE_STACK_TRACE ${DLIB_ENABLE_STACK_TRACE_STR} OFF)
    toggle_preprocessor_switch(DLIB_ENABLE_STACK_TRACE)
+   option(DLIB_USE_MKL_SEQUENTIAL ${DLIB_USE_MKL_SEQUENTIAL_STR} OFF)
 
    if(DLIB_ENABLE_ASSERTS)
       # Set these variables so they are set in the config.h.in file when dlib

dlib/cmake_utils/find_blas.cmake

@@ -110,13 +110,14 @@ if (UNIX OR MINGW)
    find_path(mkl_include_dir mkl_version.h ${mkl_include_search_path})
    mark_as_advanced(mkl_include_dir)
 
+   if(NOT DLIB_USE_MKL_SEQUENTIAL)
       # Search for the needed libraries from the MKL.  We will try to link against the mkl_rt
       # file first since this way avoids linking bugs in some cases.
       find_library(mkl_rt mkl_rt ${mkl_search_path})
       find_library(openmp_libraries iomp5 ${mkl_search_path}) 
-   mark_as_advanced(  mkl_rt  openmp_libraries )
+      mark_as_advanced(mkl_rt  openmp_libraries)
       # if we found the MKL 
-   if ( mkl_rt)
+      if (mkl_rt)
          set(mkl_libraries  ${mkl_rt} )
          set(blas_libraries  ${mkl_rt} )
          set(lapack_libraries  ${mkl_rt} )
@@ -125,21 +126,32 @@ if (UNIX OR MINGW)
          set(found_intel_mkl 1)
          message(STATUS "Found Intel MKL BLAS/LAPACK library")
       endif()
+   endif()
+   
 
    if (NOT found_intel_mkl)
       # Search for the needed libraries from the MKL.  This time try looking for a different
       # set of MKL files and try to link against those.
       find_library(mkl_core mkl_core ${mkl_search_path})
+      set(mkl_libs ${mkl_intel} ${mkl_core})
+      mark_as_advanced(mkl_libs mkl_intel mkl_core)
+      if (DLIB_USE_MKL_SEQUENTIAL)
+         find_library(mkl_sequential mkl_sequential ${mkl_search_path})
+         mark_as_advanced(mkl_sequential)
+         list(APPEND mkl_libs ${mkl_sequential})
+      else()
          find_library(mkl_thread mkl_intel_thread ${mkl_search_path})
          find_library(mkl_iomp iomp5 ${mkl_search_path})
          find_library(mkl_pthread pthread ${mkl_search_path})
+         mark_as_advanced(mkl_thread mkl_iomp mkl_pthread)
+         list(APPEND mkl_libs ${mkl_thread} ${mkl_iomp} ${mkl_pthread})
+      endif()
    
-      mark_as_advanced( mkl_intel mkl_core mkl_thread mkl_iomp mkl_pthread)
       # If we found the MKL 
-      if (mkl_intel AND mkl_core AND mkl_thread AND mkl_iomp AND mkl_pthread)
-         set(mkl_libraries ${mkl_intel} ${mkl_core} ${mkl_thread} ${mkl_iomp} ${mkl_pthread})
-         set(blas_libraries ${mkl_intel} ${mkl_core} ${mkl_thread} ${mkl_iomp} ${mkl_pthread})
-         set(lapack_libraries ${mkl_intel} ${mkl_core} ${mkl_thread} ${mkl_iomp} ${mkl_pthread})
+      if (mkl_intel AND mkl_core AND ((mkl_thread AND mkl_iomp AND mkl_pthread) OR mkl_sequential))
+         set(mkl_libraries ${mkl_libs})
+         set(blas_libraries ${mkl_libs})
+         set(lapack_libraries ${mkl_libs})
          set(blas_found 1)
          set(lapack_found 1)
          set(found_intel_mkl 1)
@@ -302,14 +314,23 @@ elseif(WIN32 AND NOT MINGW)
 
    # Search for the needed libraries from the MKL.  
    find_library(mkl_core mkl_core ${mkl_search_path})
+   set(mkl_libs ${mkl_intel} ${mkl_core})
+   mark_as_advanced(mkl_libs mkl_intel mkl_core)
+   if (DLIB_USE_MKL_SEQUENTIAL)
+     find_library(mkl_sequential mkl_sequential ${mkl_search_path})
+     mark_as_advanced(mkl_sequential)
+     list(APPEND mkl_libs ${mkl_sequential})
+   else()
      find_library(mkl_thread mkl_intel_thread ${mkl_search_path})
      find_library(mkl_iomp libiomp5md ${mkl_search_path})
+     mark_as_advanced(mkl_thread mkl_iomp)
+     list(APPEND mkl_libs ${mkl_thread} ${mkl_iomp})
+   endif()
 
-   mark_as_advanced( mkl_intel mkl_core mkl_thread  mkl_iomp)
    # If we found the MKL 
-   if (mkl_intel AND mkl_core AND mkl_thread AND mkl_iomp )
-      set(blas_libraries ${mkl_intel} ${mkl_core} ${mkl_thread} ${mkl_iomp}  )
-      set(lapack_libraries ${mkl_intel} ${mkl_core} ${mkl_thread} ${mkl_iomp} )
+   if (mkl_intel AND mkl_core AND ((mkl_thread AND mkl_iomp) OR mkl_sequential))
+      set(blas_libraries ${mkl_libs})
+      set(lapack_libraries ${mkl_libs})
       set(blas_found 1)
       set(lapack_found 1)
       message(STATUS "Found Intel MKL BLAS/LAPACK library")
@@ -324,10 +345,7 @@ elseif(WIN32 AND NOT MINGW)
          set(blas_found 0)
          set(lapack_found 0)
       endif()
-
    endif()
-
-
 endif()