Merge pull request #1505 from hjchen2/backup

Optimize general col2im to speed up transpose conv

src/operators/kernel/arm/convolution/conv_common.cpp

@@ -56,10 +56,9 @@ void InitBaseConvKernel(ConvParam<CPU> *param) {
                param->Strides()[0] == param->Strides()[1] &&
                param->Dilations()[0] == param->Dilations()[1] &&
                param->Strides()[0] == 1 && param->Dilations()[0] == 1
-#if 0
-               && param->Output()->dims()[1] >= 16 &&
-               param->Input()->dims()[1] >= 16 &&
-               param->Input()->dims()[2] <= 140 */ /* refered from ncnn */
+#if 1
+               && (param->Input()->dims()[1] >= 4 ||
+                   param->Output()->dims()[1] >= 16)
 #endif
     ) {
       param->ExecMode() = ConvParam<CPU>::EXEC_WINOGRAD3X3_FLOAT;

src/operators/math/im2col.h

@@ -25,6 +25,25 @@ namespace math {
  * Col2ImFunctor. */
 enum class ColFormat { kCFO = 0, kOCF = 1 };
 
+template <class T>
+void ExtractToImg(const T *im_data, T *col_data, const int im_height,
+                  const int im_width, const int col_height, const int col_width,
+                  const int padding_h, const int padding_w, const int stride_h,
+                  const int stride_w, const int kh, const int kw);
+
+template <class T>
+void ExtendToImg(const T *col_data, T *im_data, const int im_height,
+                 const int im_width, const int col_height, const int col_width,
+                 const int padding_h, const int padding_w, const int stride_h,
+                 const int stride_w, const int kh, const int kw);
+
+template <class T>
+void ExtendToImgV2(const T *col_data, T *im_data, const int im_height,
+                   const int im_width, const int col_height,
+                   const int col_width, const int padding_h,
+                   const int padding_w, const int stride_h, const int stride_w,
+                   const int kh, const int kernel_w);
+
 /*
  * \brief Converts the image data of three dimensions(CHW) into a
  * colData of