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_MIPS_LITHIUM_GAP_RESOLVER_MIPS_H_
6#define V8_MIPS_LITHIUM_GAP_RESOLVER_MIPS_H_
7
8#include "src/v8.h"
9
10#include "src/lithium.h"
11
12namespace v8 {
13namespace internal {
14
15class LCodeGen;
16class LGapResolver;
17
18class LGapResolver FINAL BASE_EMBEDDED {
19 public:
20  explicit LGapResolver(LCodeGen* owner);
21
22  // Resolve a set of parallel moves, emitting assembler instructions.
23  void Resolve(LParallelMove* parallel_move);
24
25 private:
26  // Build the initial list of moves.
27  void BuildInitialMoveList(LParallelMove* parallel_move);
28
29  // Perform the move at the moves_ index in question (possibly requiring
30  // other moves to satisfy dependencies).
31  void PerformMove(int index);
32
33  // If a cycle is found in the series of moves, save the blocking value to
34  // a scratch register.  The cycle must be found by hitting the root of the
35  // depth-first search.
36  void BreakCycle(int index);
37
38  // After a cycle has been resolved, restore the value from the scratch
39  // register to its proper destination.
40  void RestoreValue();
41
42  // Emit a move and remove it from the move graph.
43  void EmitMove(int index);
44
45  // Verify the move list before performing moves.
46  void Verify();
47
48  LCodeGen* cgen_;
49
50  // List of moves not yet resolved.
51  ZoneList<LMoveOperands> moves_;
52
53  int root_index_;
54  bool in_cycle_;
55  LOperand* saved_destination_;
56};
57
58} }  // namespace v8::internal
59
60#endif  // V8_MIPS_LITHIUM_GAP_RESOLVER_MIPS_H_
61