[PASS]fix conv_elementwise_tree_fuse_pass rm bug

lite/core/optimizer/mir/fusion/conv_elementwise_tree_fuse_pass.cc

@@ -45,7 +45,7 @@ void ConvElementwiseTreeFusePass::Apply(
                   << "  elementwise_type: " << elementwise_type;
           fusion::ConvElementwiseTreeFuser fuser(
               conv_type, conv_has_bias, conv_has_prelu_alpha, elementwise_type);
-          fuser(graph.get());
+          fuser.apply_impl(graph.get());
         }
       }
     }

lite/core/optimizer/mir/fusion/conv_elementwise_tree_fuser.cc

@@ -26,6 +26,7 @@ void ConvElementwiseTreeFuser::BuildPattern() {
   auto* conv_input =
       VarNode("conv_input")->assert_is_op_input(conv_type_, "Input")->AsInput();
   auto* conv_filter = VarNode("conv_filter")
+                          ->assert_is_persistable_var()
                           ->assert_is_op_input(conv_type_, "Filter")
                           ->AsInput();
   auto* elementwise_input = VarNode("elementwise_input")
@@ -35,7 +36,8 @@ void ConvElementwiseTreeFuser::BuildPattern() {
   // create intermediate nodes
   conv_output_ = VarNode("conv_output")
                      ->assert_is_op_output(conv_type_, "Output")
-                     ->assert_is_op_input(elementwise_type_, "Y");
+                     ->assert_is_op_input(elementwise_type_, "Y")
+                     ->assert_only_one_output();
 
   // create op nodes
   // The pass will not been applied if conv1x1 has already applied this pass.
@@ -79,13 +81,15 @@ void ConvElementwiseTreeFuser::BuildPattern() {
   // consider two special cases: conv with bias, conv with prelu alpha
   std::vector<PMNode*> conv_inputs{conv_input, conv_filter};
   if (conv_has_bias_) {
-    auto* conv_bias =
-        VarNode("conv_bias")->assert_is_op_input(conv_type_, "Bias");
+    auto* conv_bias = VarNode("conv_bias")
+                          ->assert_is_op_input(conv_type_, "Bias")
+                          ->assert_is_persistable_var();
     conv_inputs.push_back(conv_bias);
   }
   if (conv_has_prelu_alpha_) {
     auto* conv_alpha = VarNode("conv_alpha")
                            ->assert_is_op_input(conv_type_, "Prelu_alpha")
+                           ->assert_is_persistable_var()
                            ->AsInput();
     conv_inputs.push_back(conv_alpha);
   }
@@ -146,9 +150,9 @@ void ConvElementwiseTreeFuser::InsertNewNode(SSAGraph* graph,
   }
 
   // NOTE: Mark these node as intermediate at this place.
-  conv_output_->AsIntermediate();
-  conv_->AsIntermediate();
-  elementwise_->AsIntermediate();
+  nodes2rm_.insert(matched.at("conv"));
+  nodes2rm_.insert(matched.at("conv_output"));
+  nodes2rm_.insert(matched.at("elementwise"));
 
   auto op_desc = GenOpDesc(matched);
   auto conv_op_new = LiteOpRegistry::Global().Create(conv_type_);

lite/core/optimizer/mir/fusion/conv_elementwise_tree_fuser.h

@@ -15,6 +15,7 @@
 #pragma once
 
 #include <memory>
+#include <set>
 #include <string>
 #include "lite/core/optimizer/mir/pattern_matcher_high_api.h"
 
@@ -34,6 +35,17 @@ class ConvElementwiseTreeFuser : public FuseBase {
     conv_has_prelu_alpha_ = conv_has_prelu_alpha;
     elementwise_type_ = elementwise_type;
   }
+  size_t apply_impl(SSAGraph* graph) {
+    BuildPattern();
+    PerformPatternMatcher(graph);
+
+    for (const auto& matched : key2nodes_) {
+      InsertNewNode(graph, matched);
+    }
+
+    GraphSafeRemoveNodes(graph, nodes2rm_);
+    return key2nodes_.size();
+  }
 
   void BuildPattern() override;
   void InsertNewNode(SSAGraph* graph, const key2nodes_t& matched) override;
@@ -48,6 +60,7 @@ class ConvElementwiseTreeFuser : public FuseBase {
   PMNode* conv_output_;
   PMNode* conv_;
   PMNode* elementwise_;
+  std::set<const Node*> nodes2rm_;
 };
 
 }  // namespace fusion