1 /*
2  * Copyright (c) 2023 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef ECMASCRIPT_COMPILER_DEAD_CODE_ELIMINATION_H
17 #define ECMASCRIPT_COMPILER_DEAD_CODE_ELIMINATION_H
18 
19 #include "ecmascript/compiler/combined_pass_visitor.h"
20 
21 namespace panda::ecmascript::kungfu {
22 
23 class DeadCodeElimination : public PassVisitor {
24 public:
DeadCodeElimination(Circuit* circuit, RPOVisitor* visitor, Chunk* chunk)25     DeadCodeElimination(Circuit* circuit, RPOVisitor* visitor, Chunk* chunk)
26         : PassVisitor(circuit, chunk, visitor)
27         {
28             deadGate_ = circuit->DeadGate();
29         }
30     GateRef VisitGate(GateRef gate) override;
31 
32 private:
33     GateRef StateIsDead(GateRef gate);
34     GateRef EliminateMergeAndLoopBegin(GateRef gate);
35     GateRef EliminateBranch(GateRef gate);
36     GateRef EliminateReturn(GateRef gate);
37     GateRef EliminateIfException(GateRef gate);
38     GateRef EliminateLoopExit(GateRef gate);
39     GateRef EliminateDependSelector(GateRef gate);
40     GateRef EliminateValueSelector(GateRef gate);
41     GateRef EliminateGate(GateRef gate);
42     GateRef DeleteLoopExit(GateRef gate);
43     void TryFindAndDeleteLoopExit(GateRef gate);
44     void DecreaseAllSelectors(GateRef gate, size_t count);
45     GateRef deadGate_;
46 };
47 }
48 
49 #endif