Include the Intel MKL's iomp dll in the output folder to reduce confusino for windows users.

dlib/CMakeLists.txt

@@ -9,6 +9,9 @@ cmake_minimum_required(VERSION 2.8.12)
 if(POLICY CMP0048)
    cmake_policy(SET CMP0048 NEW)
 endif()
+if(POLICY CMP0077)
+   cmake_policy(SET CMP0077 NEW)
+endif()
 
 project(dlib)
 
@@ -954,4 +957,22 @@ if (COMMAND pybind11_add_module)
    set_target_properties(dlib PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
 endif()
 
+if (WIN32 AND mkl_iomp_dll)
+   # If we are using the Intel MKL on windows then try and copy the iomp dll
+   # file to the output folder.  We do this since a very large number of
+   # windows users don't understand that they need to add the Intel MKL's
+   # folders to their PATH to use the Intel MKL.  They then complain on the
+   # dlib forums.  Copying the Intel MKL dlls to the output directory removes
+   # the need to add the Intel MKL to the PATH.
+   if (CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+      add_custom_command(TARGET dlib POST_BUILD
+         COMMAND ${CMAKE_COMMAND} -E copy "${mkl_iomp_dll}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}
+         )
+   else()
+      add_custom_command(TARGET dlib POST_BUILD
+         COMMAND ${CMAKE_COMMAND} -E copy "${mkl_iomp_dll}" ${CMAKE_BINARY_DIR}/$<CONFIG>
+         )
+   endif()
+endif()
+
 add_library(dlib::dlib ALIAS dlib)

dlib/cmake_utils/find_blas.cmake

@@ -302,6 +302,7 @@ elseif(WIN32 AND NOT MINGW)
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries_*/windows/compiler/lib/intel64" 
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/mkl/lib/intel64"
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/tbb/lib/intel64/vc14"
+         "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/tbb/lib/intel64/vc_mt"
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/compiler/lib/intel64" 
          "C:/Program Files (x86)/Intel/Composer XE/mkl/lib/intel64"
          "C:/Program Files (x86)/Intel/Composer XE/tbb/lib/intel64/vc14"
@@ -310,6 +311,9 @@ elseif(WIN32 AND NOT MINGW)
          "C:/Program Files/Intel/Composer XE/tbb/lib/intel64/vc14"
          "C:/Program Files/Intel/Composer XE/compiler/lib/intel64"
          )
+      set (mkl_redist_path
+         "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/redist/intel64/compiler" 
+         )
       find_library(mkl_intel  mkl_intel_lp64 ${mkl_search_path})
    else()
       set( mkl_search_path
@@ -318,6 +322,7 @@ elseif(WIN32 AND NOT MINGW)
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries_*/windows/compiler/lib/ia32"
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/mkl/lib/ia32" 
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/tbb/lib/ia32/vc14" 
+         "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/tbb/lib/ia32/vc_mt"
          "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/compiler/lib/ia32"
          "C:/Program Files (x86)/Intel/Composer XE/mkl/lib/ia32"
          "C:/Program Files (x86)/Intel/Composer XE/tbb/lib/ia32/vc14"
@@ -326,6 +331,9 @@ elseif(WIN32 AND NOT MINGW)
          "C:/Program Files/Intel/Composer XE/tbb/lib/ia32/vc14"
          "C:/Program Files/Intel/Composer XE/compiler/lib/ia32"
          )
+      set (mkl_redist_path
+         "C:/Program Files (x86)/IntelSWTools/compilers_and_libraries/windows/redist/ia32/compiler" 
+         )
       find_library(mkl_intel  mkl_intel_c ${mkl_search_path})
    endif()
 
@@ -363,6 +371,18 @@ elseif(WIN32 AND NOT MINGW)
      find_library(mkl_iomp libiomp5md ${mkl_search_path})
      mark_as_advanced(mkl_thread mkl_iomp)
      list(APPEND mkl_libs ${mkl_thread} ${mkl_iomp})
+     if (mkl_iomp)
+        # See if we can find the dll that goes with this, so we can copy it to
+        # the output folder, since a very large number of windows users don't
+        # understand that they need to add the Intel MKL's folders to their
+        # PATH to use the Intel MKL.  They then complain on the dlib forums.
+        # Copying the Intel MKL dlls to the output directory removes the need
+        # to add the Intel MKL to the PATH.
+        find_file(mkl_iomp_dll "libiomp5md.dll" ${mkl_redist_path})
+        if (mkl_iomp_dll)
+            message(STATUS "FOUND libiomp5md.dll: ${mkl_iomp_dll}")
+        endif()
+     endif()
    endif()
 
    # If we found the MKL