MKLDNN residual connections fuse pass:

* implements reachability check between identity node and non-identity argument to elementwise_add
* implements handling identity node as x and as y argument to elementwise_add

paddle/fluid/framework/ir/conv_elementwise_add_mkldnn_fuse_pass.h

@@ -15,6 +15,7 @@
 #pragma once
 
 #include <string>
+#include <utility>
 #include "paddle/fluid/framework/ir/fuse_pass_base.h"
 #include "paddle/fluid/framework/ir/graph.h"
 #include "paddle/fluid/framework/ir/graph_pattern_detector.h"
@@ -23,16 +24,105 @@ namespace paddle {
 namespace framework {
 namespace ir {
 
-class ConvElementwiseAddMKLDNNFusePass : public FusePassBase {
+using graph_ptr = std::unique_ptr<ir::Graph>;
+
+void CorrectGraphEdges(Graph* graph, Node* from, Node* to);
+bool IsReachable(ir::Graph* graph, Node* from, Node* to);
+
+using handler_func = std::function<void(
+    const GraphPatternDetector::subgraph_t& subgraph, Graph* g)>;
+
+class ResidualConnectionMKLDNNFusePass : public FusePassBase {
+ private:
+  graph_ptr FuseConvAsX(const std::string& name_scope_, graph_ptr graph) const;
+  graph_ptr FuseConvAsY(const std::string& name_scope_, graph_ptr graph) const;
+
+  std::pair<bool, Node*> HasBias(const Node& op) const;
+
+  template <typename CONV_FUNC, typename ELEMENTWISE_ADD_FUNC,
+            typename HANDLER_FUNC = handler_func>
+  HANDLER_FUNC GenerateFuseHandler(
+      const patterns::Conv& conv_pattern,
+      const patterns::ElementwiseAdd& elementwise_add_pattern,
+      CONV_FUNC get_node_from_conv_op,
+      ELEMENTWISE_ADD_FUNC get_node_from_elementwise_add_op) const;
+
  public:
-  virtual ~ConvElementwiseAddMKLDNNFusePass() {}
+  virtual ~ResidualConnectionMKLDNNFusePass() {}
 
  protected:
-  std::unique_ptr<ir::Graph> ApplyImpl(std::unique_ptr<ir::Graph> graph) const;
+  std::unique_ptr<ir::Graph> ApplyImpl(graph_ptr graph) const;
 
-  const std::string name_scope_{"residual_connections_fuse_pass"};
+  const std::string name_scope_{"residual_connection_fuse_pass"};
 };
 
+template <typename CONV_FUNC, typename ELEMENTWISE_ADD_FUNC,
+          typename HANDLER_FUNC>
+HANDLER_FUNC ResidualConnectionMKLDNNFusePass::GenerateFuseHandler(
+    const patterns::Conv& conv_pattern,
+    const patterns::ElementwiseAdd& elementwise_add_pattern,
+    CONV_FUNC get_node_from_conv_op,
+    ELEMENTWISE_ADD_FUNC get_node_from_elementwise_add_op) const {
+  return [&](const GraphPatternDetector::subgraph_t& subgraph, Graph* graph) {
+    Node* conv_op;
+    Node* conv_input;
+    Node* conv_filter;
+    Node* conv_output;
+
+    Node* elementwise_add_op;
+    Node* elementwise_add_identity;
+    Node* elementwise_add_out;
+
+    std::tie(conv_op, conv_input, conv_filter, conv_output) =
+        get_node_from_conv_op(conv_pattern, subgraph);
+    std::tie(elementwise_add_op, elementwise_add_identity,
+             elementwise_add_out) =
+        get_node_from_elementwise_add_op(elementwise_add_pattern, subgraph);
+
+    if (this->FindFuseOption(*conv_op, *elementwise_add_op) != FUSE_MKLDNN)
+      return;
+
+    if (!IsReachable(graph, elementwise_add_identity, conv_output)) return;
+
+    OpDesc op_desc;
+    op_desc.SetType("conv2d");
+
+    op_desc.SetInput("Input", {conv_input->Name()});
+    op_desc.SetInput("Filter", {conv_filter->Name()});
+    op_desc.SetInput("ResidualData", {elementwise_add_identity->Name()});
+    op_desc.SetOutput("Output", {conv_output->Name()});
+
+    bool has_bias;
+    Node* conv_bias;
+
+    std::tie(has_bias, conv_bias) = this->HasBias(*conv_op);
+
+    if (has_bias) {
+      op_desc.SetInput("Bias", {conv_bias->Name()});
+    }
+
+    for (const auto& attr : conv_op->Op()->GetAttrMap()) {
+      op_desc.SetAttr(attr.first, attr.second);
+    }
+
+    op_desc.SetAttr("fuse_residual_connection", true);
+
+    auto fused_conv_op = graph->CreateOpNode(&op_desc);
+
+    IR_NODE_LINK_TO(conv_input, fused_conv_op);
+    IR_NODE_LINK_TO(conv_filter, fused_conv_op);
+    IR_NODE_LINK_TO(elementwise_add_identity, fused_conv_op);
+    IR_NODE_LINK_TO(fused_conv_op, conv_output);
+
+    if (has_bias) {
+      IR_NODE_LINK_TO(conv_bias, fused_conv_op);
+    }
+
+    CorrectGraphEdges(graph, elementwise_add_out, conv_output);
+    GraphSafeRemoveNodes(graph,
+                         {elementwise_add_out, conv_op, elementwise_add_op});
+  };
+}
 }  // namespace ir
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/framework/ir/graph_pattern_detector.cc

@@ -1084,16 +1084,12 @@ PDNode *patterns::Conv::operator()() {
   return output_var;
 }
 
-PDNode *patterns::ElementwiseAdd::operator()(PDNode *x_var) {
+PDNode *patterns::ElementwiseAdd::operator()(PDNode *x_var, PDNode *y_var) {
   auto elementwise_add_op = pattern->NewNode(elementwise_add_op_repr())
                                 ->assert_is_op("elementwise_add");
 
-  x_var->assert_is_op_input("elementwise_add", "X");
-
-  auto y_var = pattern->NewNode(elementwise_add_x_repr())
-                   ->AsInput()
-                   ->assert_is_op_input("elementwise_add", "Y");
-
+  x_var->AsInput()->assert_is_op_input("elementwise_add", "X");
+  y_var->AsInput()->assert_is_op_input("elementwise_add", "Y");
   auto out_var = pattern->NewNode(elementwise_add_out_repr())
                      ->AsOutput()
                      ->assert_is_op_output("elementwise_add", "Out");

paddle/fluid/framework/ir/graph_pattern_detector.h

@@ -664,7 +664,7 @@ struct ElementwiseAdd : public PatternBase {
   ElementwiseAdd(PDPattern* pattern, const std::string& name_scope)
       : PatternBase(pattern, name_scope, "elementwise_add") {}
 
-  PDNode* operator()(PDNode* x_var);
+  PDNode* operator()(PDNode* x_var, PDNode* y_var);
 
   PATTERN_DECL_NODE(elementwise_add_op);
   PATTERN_DECL_NODE(elementwise_add_x);