Reduce memory usage in conv layer and RoI layer for mobile inference.

paddle/function/GemmConvOp.cpp

@@ -233,6 +233,11 @@ public:
       inputGrad += inputChannels * inputHeight * inputWidth;
       outputGrad += outputChannels * outputHeight * outputWidth;
     }
+#ifdef PADDLE_MOBILE_INFERENCE
+    if (Device == DEVICE_TYPE_CPU) {
+      delete memory_;
+    }
+#endif
   }
 };
 

paddle/gserver/layers/ROIPoolLayer.cpp

@@ -84,12 +84,15 @@ void ROIPoolLayer::forward(PassType passType) {
   size_t poolChannelOffset = pooledHeight_ * pooledWidth_;
 
   real* outputData = outputValue->getData();
+  real* argmaxData = nullptr;
+  if (passType != PASS_TEST) {
     Matrix::resizeOrCreate(maxIdxs_,
                            numROIs,
                            channels_ * pooledHeight_ * pooledWidth_,
                            false,
                            false);
-  real* argmaxData = maxIdxs_->getData();
+    argmaxData = maxIdxs_->getData();
+  }
 
   for (size_t n = 0; n < numROIs; ++n) {
     // the first five elememts of each RoI should be:
@@ -128,23 +131,29 @@ void ROIPoolLayer::forward(PassType passType) {
           bool isEmpty = (hend <= hstart) || (wend <= wstart);
           size_t poolIndex = ph * pooledWidth_ + pw;
           outputData[poolIndex] = isEmpty ? 0 : -FLT_MAX;
+          if (argmaxData) {
             argmaxData[poolIndex] = -1;
+          }
 
           for (size_t h = hstart; h < hend; ++h) {
             for (size_t w = wstart; w < wend; ++w) {
               size_t index = h * width_ + w;
               if (batchData[index] > outputData[poolIndex]) {
                 outputData[poolIndex] = batchData[index];
+                if (argmaxData) {
                   argmaxData[poolIndex] = index;
                 }
               }
             }
           }
         }
+      }
       batchData += channelOffset;
       outputData += poolChannelOffset;
+      if (argmaxData) {
         argmaxData += poolChannelOffset;
       }
+    }
     bottomROIs += roiOffset;
   }
   if (useGpu_) {