Add Intel openmp as a submodule and build for x86 architectures (#8730)

* Refreshed branch intel_openmp

* Disable Intel OpenMP local build for Windows until a Windows user can fix

* Ignore 3rdparty license headers

.gitmodules

@@ -16,3 +16,6 @@
 [submodule "cub"]
 	path = cub
 	url = https://github.com/dmlc/cub
+[submodule "3rdparty/openmp"]
+	path = 3rdparty/openmp
+	url = https://github.com/llvm-mirror/openmp

CMakeLists.txt

@@ -54,10 +54,13 @@ if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/build/private/local_config.cmake)
   include(${CMAKE_CURRENT_SOURCE_DIR}/build/private/local_config.cmake)
 endif()
 
-set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/Modules;${CMAKE_MODULE_PATH}")
-
-
+if(MSVC)
+  set(SYSTEM_ARCHITECTURE x86_64)
+else()
+  EXECUTE_PROCESS( COMMAND uname -m COMMAND tr -d '\n' OUTPUT_VARIABLE SYSTEM_ARCHITECTURE)
+endif()
 
+set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake/Modules;${CMAKE_MODULE_PATH}")
 
 SET(EXTRA_OPERATORS "" CACHE PATH "EXTRA OPERATORS PATH")
 
@@ -263,11 +266,13 @@ endif()
 # ---[ OpenMP
 if(USE_OPENMP)
   find_package(OpenMP REQUIRED)
-  if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/openmp/CMakeLists.txt)
+  # This should build on Windows, but there's some problem and I don;t have a Windows box, so
+  # could a Windows user please fix?
+  if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/openmp/CMakeLists.txt AND SYSTEM_ARCHITECTURE STREQUAL "x86_64" AND NOT MSVC)
     # Intel/llvm OpenMP: https://github.com/llvm-mirror/openmp
     set(OPENMP_STANDALONE_BUILD TRUE)
     set(LIBOMP_ENABLE_SHARED FALSE)
-    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/openmp)
+    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/openmp)
     list(REMOVE_ITEM mxnet_LINKER_LIBS iomp5)
     list(APPEND mxnet_LINKER_LIBS omp)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")

LICENSE

@@ -234,6 +234,7 @@
     1. Fast R-CNN  - For details, see example/rcnn/LICENSE
     2. Faster R-CNN - For details, see example/rcnn/LICENSE
     3. tree_lstm - For details, see example/gluon/tree_lstm/LICENSE
+    4. OpenMP - For details, see 3rdparty/openmp/LICENSE.txt
 
 
     ========================================================================

tools/license_header.py

@@ -61,6 +61,7 @@
                'dmlc-core/',
                'mshadow/',
                'nnvm',
+               '3rdparty',   
                'ps-lite',
                'src/operator/mkl/',
                'src/operator/contrib/ctc_include/']