unify functions of mkldnn_fc and refine comments

paddle/gserver/layers/MKLDNNConvLayer.cpp

@@ -285,10 +285,9 @@ void MKLDNNConvLayer::resetWgtBiasValue(
   wgt = MKLDNNMatrix::create(weight_->getW(), pd->weights_primitive_desc());
   VLOG(MKLDNN_FMTS) << "Weight value format: " << wgt->getFormat();
 
-  bias = nullptr;
-  if (biases_ && biases_->getW()) {
-    bias = MKLDNNMatrix::create(biases_->getW(), pd->bias_primitive_desc());
-  }
+  bias = (biases_ && biases_->getW())
+             ? MKLDNNMatrix::create(biases_->getW(), pd->bias_primitive_desc())
+             : nullptr;
 }
 
 void MKLDNNConvLayer::resetOutValue(
@@ -356,6 +355,7 @@ void MKLDNNConvLayer::resetBwdWgtPD(
 
 void MKLDNNConvLayer::resetBwdDataPD(
     std::shared_ptr<conv_bwdData::primitive_desc>& pd) {
+  pd = nullptr;
   if (inputLayers_[0]->getOutput().grad == nullptr) {
     return;
   }
@@ -476,6 +476,7 @@ void MKLDNNConvLayer::resetWgtBiasGrad(
       << "primitive desc of weight grad and value should be equal";
   VLOG(MKLDNN_FMTS) << "weight grad format: " << wgt->getFormat();
 
+  bias = nullptr;
   if (biasVal_ == nullptr) {
     return;
   }

paddle/gserver/layers/MKLDNNFcLayer.h

@@ -18,6 +18,9 @@ limitations under the License. */
 #include "mkldnn.hpp"
 
 namespace paddle {
+typedef mkldnn::inner_product_forward fc_fwd;
+typedef mkldnn::inner_product_backward_weights fc_bwdWgt;
+typedef mkldnn::inner_product_backward_data fc_bwdData;
 
 /**
  * @brief A subclass of MKLDNNLayer fc layer.
@@ -32,6 +35,9 @@ protected:
   // if has already init the weight
   bool hasInitedWgt_;
 
+  // save forward primitive_desc, which can be used backward
+  std::shared_ptr<fc_fwd::primitive_desc> fwdPD_;
+
   // fc weight and bias
   std::unique_ptr<Weight> weight_;
   std::unique_ptr<Weight> biases_;
@@ -67,6 +73,59 @@ public:
   void convertWeightsFromPaddle() override;
 
   void convertWeightsToPaddle() override;
+
+protected:
+  /**
+   * Forward functions: reset buffers(input, output, weight and bias),
+   *                    reset primitive descriptor,
+   *                    reset pipeline.
+   */
+  void resetFwdBuffers(MKLDNNMatrixPtr& in,
+                       MKLDNNMatrixPtr& wgt,
+                       MKLDNNMatrixPtr& bias,
+                       MKLDNNMatrixPtr& out);
+  void resetInValue(MKLDNNMatrixPtr& in);
+  void resetWgtBiasValue(MKLDNNMatrixPtr& wgt, MKLDNNMatrixPtr& bias);
+  void resetOutValue(MKLDNNMatrixPtr& out);
+  void resetFwdPD(std::shared_ptr<fc_fwd::primitive_desc>& pd,
+                  MKLDNNMatrixPtr in,
+                  MKLDNNMatrixPtr wgt,
+                  MKLDNNMatrixPtr bias,
+                  MKLDNNMatrixPtr out);
+  void resetFwdPipeline(std::vector<mkldnn::primitive>& pipeline,
+                        std::shared_ptr<fc_fwd::primitive_desc>& pd,
+                        MKLDNNMatrixPtr& in,
+                        MKLDNNMatrixPtr& wgt,
+                        MKLDNNMatrixPtr& bias,
+                        MKLDNNMatrixPtr& out);
+
+  /**
+   * Backward functions: reset buffers(input, output, weight and bias),
+   *                     reset primitive descriptor for backward weight,
+   *                     reset primitive descriptor for backward data,
+   *                     reset pipeline.
+   */
+  void resetBwdBuffers(MKLDNNMatrixPtr& in,
+                       MKLDNNMatrixPtr& wgt,
+                       MKLDNNMatrixPtr& bias,
+                       MKLDNNMatrixPtr& out);
+  void resetOutGrad(MKLDNNMatrixPtr& out);
+  void resetWgtBiasGrad(MKLDNNMatrixPtr& wgt, MKLDNNMatrixPtr& bias);
+  void resetInGrad(MKLDNNMatrixPtr& in);
+  void resetBwdWgtPD(std::shared_ptr<fc_bwdWgt::primitive_desc>& pd,
+                     MKLDNNMatrixPtr& wgt,
+                     MKLDNNMatrixPtr& bias,
+                     MKLDNNMatrixPtr& out);
+  void resetBwdDataPD(std::shared_ptr<fc_bwdData::primitive_desc>& pd,
+                      MKLDNNMatrixPtr& in,
+                      MKLDNNMatrixPtr& out);
+  void resetBwdPipeline(std::vector<mkldnn::primitive>& pipeline,
+                        std::shared_ptr<fc_bwdWgt::primitive_desc>& bwdWgtPD,
+                        std::shared_ptr<fc_bwdData::primitive_desc>& bwdDataPD,
+                        MKLDNNMatrixPtr& in,
+                        MKLDNNMatrixPtr& wgt,
+                        MKLDNNMatrixPtr& bias,
+                        MKLDNNMatrixPtr& out);
 };
 
 }  // namespace paddle

paddle/math/MKLDNNMatrix.h

@@ -66,11 +66,12 @@ public:
   /**
    * Create reorder primitive.
    * Create a mkldnn::reorder handle for converting src MKLDNNMatrix to dst.
-   * checkData: for whether to check the data handle of src and dst is the same.
-   *            if true, means check it and do not want support inplace reorder;
-   *            otherwise do not check data which means the created reorder
-   *            maybe inplace buffer and do not guarantee the logical is correct
-   *            since not all format or conversion support inplace.
+   * checkData: whether to check the data handle of src and dst.
+   *            if true, it will check the data and do not allow them equal;
+   *            otherwise, it will not check them, then the reorder created
+   *            may have inplace buffer.
+   *            Do not set false, if you can not guarantee the inplace logical
+   *            would work with your reorder.
    */
   static std::shared_ptr<mkldnn::reorder> createReorder(
       const MKLDNNMatrixPtr& src,