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lithium-gap-resolver-ia32.h
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27 
28 #ifndef V8_IA32_LITHIUM_GAP_RESOLVER_IA32_H_
29 #define V8_IA32_LITHIUM_GAP_RESOLVER_IA32_H_
30 
31 #include "v8.h"
32 
33 #include "lithium.h"
34 
35 namespace v8 {
36 namespace internal {
37 
38 class LCodeGen;
39 class LGapResolver;
40 
41 class LGapResolver V8_FINAL BASE_EMBEDDED {
42  public:
43  explicit LGapResolver(LCodeGen* owner);
44 
45  // Resolve a set of parallel moves, emitting assembler instructions.
46  void Resolve(LParallelMove* parallel_move);
47 
48  private:
49  // Build the initial list of moves.
50  void BuildInitialMoveList(LParallelMove* parallel_move);
51 
52  // Perform the move at the moves_ index in question (possibly requiring
53  // other moves to satisfy dependencies).
54  void PerformMove(int index);
55 
56  // Emit any code necessary at the end of a gap move.
57  void Finish();
58 
59  // Add or delete a move from the move graph without emitting any code.
60  // Used to build up the graph and remove trivial moves.
61  void AddMove(LMoveOperands move);
62  void RemoveMove(int index);
63 
64  // Report the count of uses of operand as a source in a not-yet-performed
65  // move. Used to rebuild use counts.
66  int CountSourceUses(LOperand* operand);
67 
68  // Emit a move and remove it from the move graph.
69  void EmitMove(int index);
70 
71  // Execute a move by emitting a swap of two operands. The move from
72  // source to destination is removed from the move graph.
73  void EmitSwap(int index);
74 
75  // Ensure that the given operand is not spilled.
76  void EnsureRestored(LOperand* operand);
77 
78  // Return a register that can be used as a temp register, spilling
79  // something if necessary.
80  Register EnsureTempRegister();
81 
82  // Return a known free register different from the given one (which could
83  // be no_reg---returning any free register), or no_reg if there is no such
84  // register.
85  Register GetFreeRegisterNot(Register reg);
86 
87  // Verify that the state is the initial one, ready to resolve a single
88  // parallel move.
89  bool HasBeenReset();
90 
91  // Verify the move list before performing moves.
92  void Verify();
93 
94  LCodeGen* cgen_;
95 
96  // List of moves not yet resolved.
97  ZoneList<LMoveOperands> moves_;
98 
99  // Source and destination use counts for the general purpose registers.
100  int source_uses_[Register::kMaxNumAllocatableRegisters];
101  int destination_uses_[Register::kMaxNumAllocatableRegisters];
102 
103  // If we had to spill on demand, the currently spilled register's
104  // allocation index.
105  int spilled_register_;
106 };
107 
108 } } // namespace v8::internal
109 
110 #endif // V8_IA32_LITHIUM_GAP_RESOLVER_IA32_H_
static const int kMaxNumAllocatableRegisters
#define BASE_EMBEDDED
Definition: allocation.h:68