Add c-api interface, paddle_gradient_machine_create_for_inference_with_parameters,

to create a gradient machine for inference using merged model with parameters
which is genearted by `paddle merge_model`.

cmake/flags.cmake

@@ -9,10 +9,12 @@ function(CheckCompilerCXX11Flag)
         if(${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 4.8)
             message(FATAL_ERROR "Unsupported GCC version. GCC >= 4.8 required.")
         endif()
-        # TODO(qijun) gcc 4.9 or later versions raise SEGV due to the optimization problem.
-        # Use Debug mode instead for now.
-        if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 4.9 OR CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 4.9) 
-            set(CMAKE_BUILD_TYPE "Debug" CACHE STRING "" FORCE)
+        if(NOT ANDROID)
+            # TODO(qijun) gcc 4.9 or later versions raise SEGV due to the optimization problem.
+            # Use Debug mode instead for now.
+            if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 4.9 OR CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 4.9)
+                set(CMAKE_BUILD_TYPE "Debug" CACHE STRING "" FORCE)
+            endif()
         endif()
     elseif(CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang" OR CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
         # cmake >= 3.0 compiler id "AppleClang" on Mac OS X, otherwise "Clang"

paddle/capi/gradient_machine.cpp

@@ -54,6 +54,31 @@ paddle_error paddle_gradient_machine_create_for_inference(
   return kPD_NO_ERROR;
 }
 
+paddle_error paddle_gradient_machine_create_for_inference_with_parameters(
+    paddle_gradient_machine* machine, void* mergedModel, uint64_t size) {
+  if (mergedModel == nullptr) return kPD_NULLPTR;
+  std::istringstream is(std::string(static_cast<char*>(mergedModel), size));
+  int64_t modelConfigSize = 0;
+  is.read((char*)(&modelConfigSize), sizeof(modelConfigSize));
+  std::string modelConfigProtobuf;
+  modelConfigProtobuf.resize(modelConfigSize);
+  is.read(&modelConfigProtobuf[0], modelConfigSize);
+  paddle::TrainerConfig config;
+  if (!config.ParseFromString(modelConfigProtobuf) || !config.IsInitialized()) {
+    return kPD_PROTOBUF_ERROR;
+  }
+  auto ptr = new paddle::capi::CGradientMachine();
+  ptr->machine.reset(paddle::GradientMachine::create(
+      config.model_config(), CREATE_MODE_TESTING, {paddle::PARAMETER_VALUE}));
+  std::vector<paddle::ParameterPtr>& parameters = ptr->machine->getParameters();
+  for (auto& para : parameters) {
+    para->load(is);
+  }
+
+  *machine = ptr;
+  return kPD_NO_ERROR;
+}
+
 paddle_error paddle_gradient_machine_destroy(paddle_gradient_machine machine) {
   delete cast(machine);
   return kPD_NO_ERROR;

paddle/capi/gradient_machine.h

@@ -36,6 +36,18 @@ typedef void* paddle_gradient_machine;
 PD_API paddle_error paddle_gradient_machine_create_for_inference(
     paddle_gradient_machine* machine, void* modelConfigProtobuf, int size);
 
+/**
+ * @brief Create a gradient machine used for model inference, using config with
+ *        parameters which is generated by `paddle merge_model`.
+ * @param [out] machine that used for model inference.
+ * @param [in] mergedModel
+ * @param [in] size
+ * @return paddle_error
+ */
+PD_API paddle_error
+paddle_gradient_machine_create_for_inference_with_parameters(
+    paddle_gradient_machine* machine, void* mergedModel, uint64_t size);
+
 /**
  * @brief Load parameter from disk.
  * @param machine Gradient Machine.

paddle/gserver/gradientmachines/NeuralNetwork.cpp

@@ -24,8 +24,6 @@ limitations under the License. */
 #include "paddle/gserver/layers/AgentLayer.h"
 #include "paddle/utils/Stat.h"
 
-#include <iostream>
-
 namespace paddle {
 void parameterInitNN(int paramId,
                      Parameter* para,