Demo CMakeLists add openmp flag. (#27848)

paddle/fluid/inference/api/demo_ci/CMakeLists.txt

@@ -47,19 +47,24 @@ if (WIN32)
   add_definitions("/DGOOGLE_GLOG_DLL_DECL=")
   option(MSVC_STATIC_CRT "use static C Runtime library by default" ON)
   if (MSVC_STATIC_CRT)
-    set(CMAKE_C_FLAGS_DEBUG   "${CMAKE_C_FLAGS_DEBUG} /bigobj /MTd")
-    set(CMAKE_C_FLAGS_RELEASE  "${CMAKE_C_FLAGS_RELEASE} /bigobj /MT")
-    set(CMAKE_CXX_FLAGS_DEBUG  "${CMAKE_CXX_FLAGS_DEBUG} /bigobj /MTd")
-    set(CMAKE_CXX_FLAGS_RELEASE   "${CMAKE_CXX_FLAGS_RELEASE} /bigobj /MT")
+    if (WITH_MKL)
+      set(FLAG_OPENMP "/openmp")
+    endif()
+    set(CMAKE_C_FLAGS_DEBUG   "${CMAKE_C_FLAGS_DEBUG} /bigobj /MTd ${FLAG_OPENMP}")
+    set(CMAKE_C_FLAGS_RELEASE  "${CMAKE_C_FLAGS_RELEASE} /bigobj /MT ${FLAG_OPENMP}")
+    set(CMAKE_CXX_FLAGS_DEBUG  "${CMAKE_CXX_FLAGS_DEBUG} /bigobj /MTd ${FLAG_OPENMP}")
+    set(CMAKE_CXX_FLAGS_RELEASE   "${CMAKE_CXX_FLAGS_RELEASE} /bigobj /MT ${FLAG_OPENMP}")
     safe_set_static_flag()
     if (WITH_STATIC_LIB)
       add_definitions(-DSTATIC_LIB)
     endif()
   endif()
 else()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+  if(WITH_MKL)
+    set(FLAG_OPENMP "-fopenmp")
+  endif()
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 ${FLAG_OPENMP}")
 endif()
-message("flags" ${CMAKE_CXX_FLAGS})
 
 if(WITH_GPU)
   if(NOT WIN32)