cmake add half (#1609)

Former-commit-id: 58b9b56676f69c50ea6cdc80f474a3bde8d4becb

cmake/third_party.cmake

@@ -12,6 +12,7 @@ include(libjpeg-turbo)
 include(opencv)
 include(eigen)
 include(cocoapi)
+include(half)
 
 if (BUILD_CUDA)
   set(CUDA_SEPARABLE_COMPILATION ON)
@@ -90,6 +91,7 @@ set(oneflow_third_party_dependencies
   eigen
   cocoapi_copy_headers_to_destination
   cocoapi_copy_libs_to_destination
+  half_copy_headers_to_destination
 )
 
 include_directories(
@@ -104,6 +106,7 @@ include_directories(
     ${OPENCV_INCLUDE_DIR}
     ${EIGEN_INCLUDE_DIR}
     ${COCOAPI_INCLUDE_DIR}
+    ${HALF_INCLUDE_DIR}
 )
 
 if (BUILD_CUDA)
@@ -124,3 +127,5 @@ if (BUILD_CUDA)
     ${NCCL_INCLUDE_DIR}
 )
 endif()
+
+add_definitions(-DHALF_ENABLE_CPP11_USER_LITERALS=0)

cmake/third_party/half.cmake

+include (ExternalProject)
+
+set(HALF_INCLUDE_DIR ${THIRD_PARTY_DIR}/half/include)
+
+set(HALF_URL https://cfhcable.dl.sourceforge.net/project/half/half/1.12.0/half-1.12.0.zip)
+set(HALF_BASE_DIR ${CMAKE_CURRENT_BINARY_DIR}/half/src/half)
+
+set(HALF_HEADERS
+    "${HALF_BASE_DIR}/include/half.hpp"
+)
+
+if(BUILD_THIRD_PARTY)
+
+ExternalProject_Add(half
+    PREFIX half
+    URL ${HALF_URL}
+    UPDATE_COMMAND ""
+    CONFIGURE_COMMAND ""
+    BUILD_COMMAND ""
+    BUILD_IN_SOURCE 1
+    INSTALL_COMMAND ""
+)
+
+add_custom_target(half_create_header_dir
+    COMMAND ${CMAKE_COMMAND} -E make_directory ${HALF_INCLUDE_DIR}
+    DEPENDS half)
+
+add_custom_target(half_copy_headers_to_destination
+    DEPENDS half_create_header_dir)
+
+foreach(header_file ${HALF_HEADERS})
+    add_custom_command(TARGET half_copy_headers_to_destination PRE_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy_if_different ${header_file} ${HALF_INCLUDE_DIR})
+endforeach()
+endif(BUILD_THIRD_PARTY)