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_EARLY_ELIMINATION_H
17#define ECMASCRIPT_COMPILER_EARLY_ELIMINATION_H
18
19#include "ecmascript/compiler/circuit_builder.h"
20#include "ecmascript/compiler/combined_pass_visitor.h"
21#include "ecmascript/compiler/gate_accessor.h"
22#include "ecmascript/mem/chunk_containers.h"
23
24namespace panda::ecmascript::kungfu {
25class EarlyElimination;
26
27class DependInfoNode : public ChunkObject {
28public:
29    DependInfoNode(Chunk* chunk) : chunk_(chunk) {}
30    ~DependInfoNode() = default;
31
32    GateRef LookupFrameState() const;
33    GateRef LookupNode(EarlyElimination* elimination, GateRef gate);
34    GateRef LookupCheckedNode(EarlyElimination* elimination, GateRef gate);
35    DependInfoNode* UpdateNode(GateRef gate);
36    DependInfoNode* UpdateFrameState(GateRef framestate);
37    DependInfoNode* UpdateStoreProperty(EarlyElimination* elimination, GateRef gate);
38    bool Equals(DependInfoNode* that);
39    void Merge(EarlyElimination* elimination, DependInfoNode* that);
40    void GetGates(std::vector<GateRef>& gates) const;
41    void CopyFrom(DependInfoNode *other)
42    {
43        head_ = other->head_;
44        size_ = other->size_;
45        frameState_ = other->frameState_;
46    }
47private:
48    struct Node {
49        Node(GateRef gate, Node* next) : gate(gate), next(next) {}
50        GateRef gate;
51        Node *next;
52    };
53
54    GateRef frameState_ {Circuit::NullGate()};
55    Node *head_{nullptr};
56    size_t size_ {0};
57    Chunk* chunk_;
58};
59
60class EarlyElimination : public PassVisitor {
61public:
62    EarlyElimination(Circuit* circuit, RPOVisitor* visitor, Chunk* chunk,
63        bool enableMemoryAnalysis, bool enableFrameStateElimination)
64        : PassVisitor(circuit, chunk, visitor), dependChains_(chunk), renames_(chunk),
65          enableMemoryAnalysis_(enableMemoryAnalysis),
66          enableFrameStateElimination_(enableFrameStateElimination) {}
67
68    ~EarlyElimination() = default;
69
70    void Initialize() override;
71    GateRef VisitGate(GateRef gate) override;
72    bool CheckReplacement(GateRef lhs, GateRef rhs);
73    bool CheckRenameReplacement(GateRef lhs, GateRef rhs);
74    bool MayAccessOneMemory(GateRef lhs, GateRef rhs);
75    bool CompareOrder(GateRef lhs, GateRef rhs);
76private:
77
78    DependInfoNode* GetDependChain(GateRef dependIn)
79    {
80        size_t idx = acc_.GetId(dependIn);
81        ASSERT(idx <= circuit_->GetMaxGateId());
82        return dependChains_[idx];
83    }
84
85    GateRef VisitDependEntry(GateRef gate);
86    GateRef UpdateDependChain(GateRef gate, DependInfoNode* dependInfo);
87    DependInfoNode* UpdateWrite(GateRef gate, DependInfoNode* dependInfo);
88    GateRef TryEliminateGate(GateRef gate);
89    GateRef TryEliminateFrameState(GateRef gate);
90    GateRef TryEliminateOther(GateRef gate);
91    GateRef TryEliminateDependSelector(GateRef gate);
92    DependInfoNode* GetLoopDependInfo(GateRef depend);
93    GateRef Rename(GateRef gate);
94
95    ChunkVector<DependInfoNode*> dependChains_;
96    ChunkVector<GateRef> renames_;
97    bool enableMemoryAnalysis_ {true};
98    bool enableFrameStateElimination_ {true};
99};
100}  // panda::ecmascript::kungfu
101#endif  // ECMASCRIPT_COMPILER_EARLY_ELIMINATION_H
102