add openmp support

CMakeLists.txt

@@ -16,6 +16,11 @@ file(GLOB_RECURSE PADDLE_MOBILE_H src/*.h)
 
 include_directories(src/)
 
+option(USE_OPENMP "openmp support" ON)
+if(USE_OPENMP)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fopenmp")
+endif()
+
 add_library(paddle-mobile SHARED ${PADDLE_MOBILE_CC} ${PADDLE_MOBILE_H})
 
 add_subdirectory(test)

src/operators/kernel/arm/sigmoid_kernel.cpp

@@ -51,9 +51,9 @@ void sigmoid(const Tensor *X, Tensor *Y) {
   int inner_size = paddle_mobile::framework::product(inner_ddim);
   DLOG << "step6";
 
-#pragma omp parallel for
   DLOG << "outsize=" << out_size;
   DLOG << "innersize=" << inner_size;
+  #pragma omp parallel for
   for (int i = 0; i < out_size; ++i) {
     const float *input_outer_ptr = input + i * inner_size;
     float *output_outer_ptr = output + i * inner_size;