Fix a bug in save_inference_model and prune when the program is initailized by load_inference_model (#10011)

* Fix bug in save_inference_model and prune when the program is initialized by load_inference_program.

* Save the transpiled program instead.

paddle/fluid/framework/op_desc.h

@@ -119,7 +119,7 @@ class OpDesc {
 
   void InferVarType(BlockDesc *block) const;
 
-  void MarkAsTarget() { desc_.set_is_target(true); }
+  void SetIsTarget(bool is_target) { desc_.set_is_target(is_target); }
 
   void Flush();
 

paddle/fluid/pybind/protobuf.cc

@@ -127,6 +127,8 @@ void BindProgramDesc(pybind11::module *m) {
       .def("block", &pd::ProgramDesc::MutableBlock,
            pybind11::return_value_policy::reference)
       .def("num_blocks", &pd::ProgramDesc::Size)
+      .def("get_feed_target_names", &pd::ProgramDesc::GetFeedTargetNames)
+      .def("get_fetch_target_names", &pd::ProgramDesc::GetFetchTargetNames)
       .def("serialize_to_string", SerializeMessage<pd::ProgramDesc>)
       .def("parse_from_string",
            [](pd::ProgramDesc &program_desc, const std::string &data) {
@@ -299,6 +301,7 @@ void BindOpDesc(pybind11::module *m) {
       .def("check_attrs", &pd::OpDesc::CheckAttrs)
       .def("infer_shape", &pd::OpDesc::InferShape)
       .def("infer_var_type", &pd::OpDesc::InferVarType)
+      .def("set_is_target", &pd::OpDesc::SetIsTarget)
       .def("serialize_to_string", SerializeMessage<pd::OpDesc>)
       .def("block", &pd::OpDesc::Block,
            pybind11::return_value_policy::reference);

paddle/fluid/pybind/pybind.cc

@@ -294,7 +294,7 @@ All parameter, weight, gradient are variables in Paddle.
                     const std::vector<std::array<size_t, 2>> &targets) {
     ProgramDesc prog_with_targets(origin);
     for (const auto &t : targets) {
-      prog_with_targets.MutableBlock(t[0])->Op(t[1])->MarkAsTarget();
+      prog_with_targets.MutableBlock(t[0])->Op(t[1])->SetIsTarget(true);
     }
     proto::ProgramDesc pruned_desc;
     Prune(*prog_with_targets.Proto(), &pruned_desc);

python/paddle/fluid/framework.py

@@ -1070,6 +1070,12 @@ class Program(object):
         for t in targets:
             if not isinstance(t, Operator):
                 if isinstance(t, Variable):
+                    if t.op is None:
+                        global_block = self.global_block()
+                        for op in global_block.ops:
+                            if t.name in op.output_arg_names:
+                                t.op = op
+                                break
                     t = t.op
                 else:
                     raise ValueError(("All targets of prune() can only be "

python/paddle/fluid/io.py

@@ -340,6 +340,13 @@ def save_inference_model(dirname,
     if not os.path.isdir(dirname):
         os.makedirs(dirname)
 
+    # Clear the is_target information and remove the existed feed and fetch op
+    global_block = main_program.global_block()
+    for i, op in enumerate(global_block.ops):
+        op.desc.set_is_target(False)
+        if op.type == "feed" or op.type == "fetch":
+            global_block.remove_op(i)
+
     pruned_program = main_program.prune(targets=target_vars)
     inference_program = pruned_program.inference_optimize()
     fetch_var_names = [v.name for v in target_vars]
@@ -362,24 +369,6 @@ def save_inference_model(dirname,
     save_persistables(executor, dirname, inference_program, params_filename)
 
 
-def get_feed_targets_names(program):
-    feed_targets_names = []
-    global_block = program.global_block()
-    for op in global_block.ops:
-        if op.desc.type() == 'feed':
-            feed_targets_names.insert(0, op.desc.output('Out')[0])
-    return feed_targets_names
-
-
-def get_fetch_targets_names(program):
-    fetch_targets_names = []
-    global_block = program.global_block()
-    for op in global_block.ops:
-        if op.desc.type() == 'fetch':
-            fetch_targets_names.append(op.desc.input('X')[0])
-    return fetch_targets_names
-
-
 def load_inference_model(dirname,
                          executor,
                          model_filename=None,
@@ -418,8 +407,8 @@ def load_inference_model(dirname,
     program = Program.parse_from_string(program_desc_str)
     load_persistables(executor, dirname, program, params_filename)
 
-    feed_target_names = get_feed_targets_names(program)
-    fetch_target_names = get_fetch_targets_names(program)
+    feed_target_names = program.desc.get_feed_target_names()
+    fetch_target_names = program.desc.get_fetch_target_names()
     fetch_targets = [
         program.global_block().var(name) for name in fetch_target_names
     ]

python/paddle/fluid/tests/book/test_image_classification.py

@@ -248,6 +248,10 @@ def infer(use_cuda, save_dirname=None):
 
         print("infer results: ", results[0])
 
+        fluid.io.save_inference_model(save_dirname, feed_target_names,
+                                      fetch_targets, exe,
+                                      inference_transpiler_program)
+
 
 def main(net_type, use_cuda, is_local=True):
     if use_cuda and not fluid.core.is_compiled_with_cuda():