// Copyright (c) 2021 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.

#pragma once

#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"
#include "paddle/fluid/framework/ir/pass.h"

namespace paddle {
namespace framework {
namespace ir {

//     |
// layer_norm
//     |
//  reshape2
//     |
//  reshape2                            |
//     |           fuse       layernorm_shift_patition
// transpose2       ->                  |
//     |                             other_op
//  reshape2
//     |
//  reshape2
//     |
//  other_op
//
// or
//
//     |
// layer_norm
//     |
//  reshape2
//     |
//    roll
//     |
//  reshape2                            |
//     |           fuse       layernorm_shift_patition
// transpose2       ->                  |
//     |                             other_op
//  reshape2
//     |
//  reshape2
//     |
//  other_op

class LayerNormShiftPartitionFusePass : public FusePassBase {
 public:
  LayerNormShiftPartitionFusePass();
  virtual ~LayerNormShiftPartitionFusePass() {}

 protected:
  void ApplyImpl(ir::Graph *graph) const override;
  int ApplyPattern(ir::Graph *graph, bool with_roll) const;

 private:
  const std::string scope_name_{"layernorm_shift_partition_fuse"};
};

}  // namespace ir
}  // namespace framework
}  // namespace paddle
