!4940 modify conv to make fp16 run pass

Merge pull request !4940 from zhaozhenlong/lite/issue/modify_conv_for_fp16

mindspore/lite/src/runtime/kernel/arm/fp16/convolution_fp16.cc

@@ -235,13 +235,15 @@ kernel::LiteKernel *CpuConvFp16KernelCreator(const std::vector<lite::tensor::Ten
   conv_param->input_w_ = inputs.front()->Width();
   conv_param->output_h_ = outputs.front()->Height();
   conv_param->output_w_ = outputs.front()->Width();
-  bool prefer_flag = false;
-  if (conv_param->output_h_ * conv_param->output_w_ > 64) {
-    prefer_flag = true;
-  }
+  // bool prefer_flag = false;
+  //  if (conv_param->output_h_ * conv_param->output_w_ > 64) {
+  //    prefer_flag = true;
+  //  }
 
   kernel::LiteKernel *kernel = nullptr;
-  if (kernel_h == 1 && kernel_w == 1) {
+  if (kernel_h == 3 && kernel_w == 3 && stride_h == 1 && stride_w == 1 && dilation_h == 1 && dilation_w == 1) {
+    kernel = new (std::nothrow) kernel::Convolution3x3FP16CPUKernel(opParameter, inputs, outputs, ctx, primitive);
+  } else if (kernel_h == 1 && kernel_w == 1) {
     // kernel = new (std::nothrow) kernel::Convolution1x1FP16CPUKernel(opParameter, inputs, outputs, ctx, primitive);
     kernel = new (std::nothrow) kernel::ConvolutionFP16CPUKernel(opParameter, inputs, outputs, ctx, primitive);
   } else {
@@ -253,9 +255,6 @@ kernel::LiteKernel *CpuConvFp16KernelCreator(const std::vector<lite::tensor::Ten
     if (use_winograd) {
       kernel = new (std::nothrow)
         kernel::ConvolutionWinogradFP16CPUKernel(opParameter, inputs, outputs, ctx, primitive, out_unit);
-    } else if (prefer_flag && kernel_h == 3 && kernel_w == 3 && stride_h == 1 && stride_w == 1 && dilation_h == 1 &&
-               dilation_w == 1) {
-      kernel = new (std::nothrow) kernel::Convolution3x3FP16CPUKernel(opParameter, inputs, outputs, ctx, primitive);
     }
     if (kernel_h != 1 && kernel_w != 1 && !use_winograd) {
       kernel = new (std::nothrow) kernel::ConvolutionFP16CPUKernel(opParameter, inputs, outputs, ctx, primitive);