1// Copyright 2014 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_COMPILER_BACKEND_MOVE_OPTIMIZER_H_
6#define V8_COMPILER_BACKEND_MOVE_OPTIMIZER_H_
7
8#include "src/compiler/backend/instruction.h"
9#include "src/globals.h"
10#include "src/zone/zone-containers.h"
11
12namespace v8 {
13namespace internal {
14namespace compiler {
15
16class V8_EXPORT_PRIVATE MoveOptimizer final {
17 public:
18 MoveOptimizer(Zone* local_zone, InstructionSequence* code);
19 void Run();
20
21 private:
22 using MoveOpVector = ZoneVector<MoveOperands*>;
23 using Instructions = ZoneVector<Instruction*>;
24
25 InstructionSequence* code() const { return code_; }
26 Zone* local_zone() const { return local_zone_; }
27 Zone* code_zone() const { return code()->zone(); }
28 MoveOpVector& local_vector() { return local_vector_; }
29
30 // Consolidate moves into the first gap.
31 void CompressGaps(Instruction* instr);
32
33 // Attempt to push down to the last instruction those moves that can.
34 void CompressBlock(InstructionBlock* block);
35
36 // Consolidate moves into the first gap.
37 void CompressMoves(ParallelMove* left, MoveOpVector* right);
38
39 // Push down those moves in the gap of from that do not change the
40 // semantics of the from instruction, nor the semantics of the moves
41 // that remain behind.
42 void MigrateMoves(Instruction* to, Instruction* from);
43
44 void RemoveClobberedDestinations(Instruction* instruction);
45
46 const Instruction* LastInstruction(const InstructionBlock* block) const;
47
48 // Consolidate common moves appearing across all predecessors of a block.
49 void OptimizeMerge(InstructionBlock* block);
50 void FinalizeMoves(Instruction* instr);
51
52 Zone* const local_zone_;
53 InstructionSequence* const code_;
54 MoveOpVector local_vector_;
55
56 // Reusable buffers for storing operand sets. We need at most two sets
57 // at any given time, so we create two buffers.
58 ZoneVector<InstructionOperand> operand_buffer1;
59 ZoneVector<InstructionOperand> operand_buffer2;
60
61 DISALLOW_COPY_AND_ASSIGN(MoveOptimizer);
62};
63
64} // namespace compiler
65} // namespace internal
66} // namespace v8
67
68#endif // V8_COMPILER_BACKEND_MOVE_OPTIMIZER_H_
69