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_IA32_LITHIUM_GAP_RESOLVER_IA32_H_ 6 #define V8_IA32_LITHIUM_GAP_RESOLVER_IA32_H_ 7 8 #include "src/v8.h" 9 10 #include "src/lithium.h" 11 12 namespace v8 { 13 namespace internal { 14 15 class LCodeGen; 16 class LGapResolver; 17 18 class LGapResolver V8_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 // Emit any code necessary at the end of a gap move. 34 void Finish(); 35 36 // Add or delete a move from the move graph without emitting any code. 37 // Used to build up the graph and remove trivial moves. 38 void AddMove(LMoveOperands move); 39 void RemoveMove(int index); 40 41 // Report the count of uses of operand as a source in a not-yet-performed 42 // move. Used to rebuild use counts. 43 int CountSourceUses(LOperand* operand); 44 45 // Emit a move and remove it from the move graph. 46 void EmitMove(int index); 47 48 // Execute a move by emitting a swap of two operands. The move from 49 // source to destination is removed from the move graph. 50 void EmitSwap(int index); 51 52 // Ensure that the given operand is not spilled. 53 void EnsureRestored(LOperand* operand); 54 55 // Return a register that can be used as a temp register, spilling 56 // something if necessary. 57 Register EnsureTempRegister(); 58 59 // Return a known free register different from the given one (which could 60 // be no_reg---returning any free register), or no_reg if there is no such 61 // register. 62 Register GetFreeRegisterNot(Register reg); 63 64 // Verify that the state is the initial one, ready to resolve a single 65 // parallel move. 66 bool HasBeenReset(); 67 68 // Verify the move list before performing moves. 69 void Verify(); 70 71 LCodeGen* cgen_; 72 73 // List of moves not yet resolved. 74 ZoneList<LMoveOperands> moves_; 75 76 // Source and destination use counts for the general purpose registers. 77 int source_uses_[Register::kMaxNumAllocatableRegisters]; 78 int destination_uses_[Register::kMaxNumAllocatableRegisters]; 79 80 // If we had to spill on demand, the currently spilled register's 81 // allocation index. 82 int spilled_register_; 83 }; 84 85 } } // namespace v8::internal 86 87 #endif // V8_IA32_LITHIUM_GAP_RESOLVER_IA32_H_ 88
