1// Copyright 2011 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_CRANKSHAFT_MIPS_LITHIUM_GAP_RESOLVER_MIPS_H_
6#define V8_CRANKSHAFT_MIPS_LITHIUM_GAP_RESOLVER_MIPS_H_
7
8#include "src/crankshaft/lithium.h"
9
10namespace v8 {
11namespace internal {
12
13class LCodeGen;
14class LGapResolver;
15
16class LGapResolver final BASE_EMBEDDED {
17 public:
18  explicit LGapResolver(LCodeGen* owner);
19
20  // Resolve a set of parallel moves, emitting assembler instructions.
21  void Resolve(LParallelMove* parallel_move);
22
23 private:
24  // Build the initial list of moves.
25  void BuildInitialMoveList(LParallelMove* parallel_move);
26
27  // Perform the move at the moves_ index in question (possibly requiring
28  // other moves to satisfy dependencies).
29  void PerformMove(int index);
30
31  // If a cycle is found in the series of moves, save the blocking value to
32  // a scratch register.  The cycle must be found by hitting the root of the
33  // depth-first search.
34  void BreakCycle(int index);
35
36  // After a cycle has been resolved, restore the value from the scratch
37  // register to its proper destination.
38  void RestoreValue();
39
40  // Emit a move and remove it from the move graph.
41  void EmitMove(int index);
42
43  // Verify the move list before performing moves.
44  void Verify();
45
46  LCodeGen* cgen_;
47
48  // List of moves not yet resolved.
49  ZoneList<LMoveOperands> moves_;
50
51  int root_index_;
52  bool in_cycle_;
53  LOperand* saved_destination_;
54};
55
56}  // namespace internal
57}  // namespace v8
58
59#endif  // V8_CRANKSHAFT_MIPS_LITHIUM_GAP_RESOLVER_MIPS_H_
60