add assign_value_eliminate_pass to remove assign_value op. test=develop

lite/api/paddle_use_passes.h

@@ -47,3 +47,4 @@ USE_MIR_PASS(npu_subgraph_pass);
 USE_MIR_PASS(xpu_subgraph_pass);
 USE_MIR_PASS(weight_quantization_preprocess_pass);
 USE_MIR_PASS(quantized_op_attributes_inference_pass);
+USE_MIR_PASS(assign_value_eliminate_pass);

lite/core/mir/CMakeLists.txt

@@ -23,6 +23,7 @@ lite_cc_library(mir_passes
       fusion/sequence_pool_concat_fuse_pass.cc
       elimination/identity_scale_eliminate_pass.cc
       elimination/elementwise_mul_constant_eliminate_pass.cc
+      elimination/assign_value_eliminate_pass.cc
       static_kernel_pick_pass.cc
       variable_place_inference_pass.cc
       type_target_cast_pass.cc

lite/core/mir/elimination/assign_value_eliminate_pass.cc

+// Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "lite/core/mir/pass.h"
+#include "lite/core/mir/pass_registry.h"
+#include "lite/core/mir/pattern_matcher_high_api.h"
+
+namespace paddle {
+namespace lite {
+namespace mir {
+
+namespace {
+
+template <class T>
+void TensorFromVector(const std::vector<T>& src, lite::Tensor* dst) {
+  auto* src_ptr = static_cast<const void*>(src.data());
+  auto* dst_ptr = static_cast<void*>(dst->mutable_data<T>());
+  auto size = src.size() * sizeof(T);
+  std::memcpy(dst_ptr, src_ptr, size);
+}
+
+class Eliminator : public FuseBase {
+ public:
+  void BuildPattern() override {
+    auto* assign_value_op = OpNode("assign_value", "assign_value");
+    auto* out = VarNode("out")->assert_is_op_output("assign_value", "Out");
+    *assign_value_op >> *out;
+  }
+
+ private:
+  void InsertNewNode(SSAGraph* graph, const key2nodes_t& matched) override {
+    auto* assign_node = matched.at("assign_value");
+    auto* scope = assign_node->stmt()->op()->scope();
+    auto* op_info = assign_node->stmt()->op()->op_info();
+    auto shape = op_info->GetAttr<std::vector<int>>("shape");
+    auto dtype = op_info->GetAttr<int>("dtype");
+    auto fp32_values = op_info->GetAttr<std::vector<float>>("fp32_values");
+    auto int32_values = op_info->GetAttr<std::vector<int>>("int32_values");
+    auto* out = matched.at("out");
+    auto* out_tensor = scope->FindVar(out->arg()->name)
+                           ->GetMutable<lite::Tensor>();
+    if (dtype == static_cast<int>(lite::core::FluidType::INT32)) {
+      TensorFromVector(int32_values, out_tensor);
+    } else if (dtype == static_cast<int>(lite::core::FluidType::FP32)) {
+      TensorFromVector(fp32_values, out_tensor);
+    } else {
+      LOG(FATAL) << "Unsupported dtype for assign_value_op:" << dtype;
+    }
+    GraphSafeRemoveNodes(graph, {matched.at("assign_value")});
+
+  }
+};
+
+}  // namespace
+
+class AssignValueEliminatePass : public ProgramPass {
+ public:
+  void Apply(const std::unique_ptr<SSAGraph>& graph) override {
+    Eliminator eliminator;
+    eliminator(graph.get());
+  }
+};
+
+}  // namespace mir
+}  // namespace lite
+}  // namespace paddle
+
+REGISTER_MIR_PASS(assign_value_eliminate_pass,
+                  paddle::lite::mir::AssignValueEliminatePass)
+    .BindTargets({TARGET(kAny)});

lite/core/optimizer.h

@@ -71,6 +71,7 @@ class Optimizer {
            "identity_scale_eliminate_pass",               //
            "elementwise_mul_constant_eliminate_pass",     //
            "lite_sequence_pool_concat_fuse_pass",         //
+           "assign_value_eliminate_pass",
 #if (defined LITE_WITH_LIGHT_WEIGHT_FRAMEWORK) || (defined LITE_WITH_CUDA) || \
     (defined LITE_WITH_ARM)
            "lite_elementwise_add_activation_fuse_pass",  //