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_IA32_LITHIUM_GAP_RESOLVER_IA32_H_ 6 #define V8_CRANKSHAFT_IA32_LITHIUM_GAP_RESOLVER_IA32_H_ 7 8 #include "src/crankshaft/lithium.h" 9 10 namespace v8 { 11 namespace internal { 12 13 class LCodeGen; 14 class LGapResolver; 15 16 class 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 // Emit any code necessary at the end of a gap move. 32 void Finish(); 33 34 // Add or delete a move from the move graph without emitting any code. 35 // Used to build up the graph and remove trivial moves. 36 void AddMove(LMoveOperands move); 37 void RemoveMove(int index); 38 39 // Report the count of uses of operand as a source in a not-yet-performed 40 // move. Used to rebuild use counts. 41 int CountSourceUses(LOperand* operand); 42 43 // Emit a move and remove it from the move graph. 44 void EmitMove(int index); 45 46 // Execute a move by emitting a swap of two operands. The move from 47 // source to destination is removed from the move graph. 48 void EmitSwap(int index); 49 50 // Ensure that the given operand is not spilled. 51 void EnsureRestored(LOperand* operand); 52 53 // Return a register that can be used as a temp register, spilling 54 // something if necessary. 55 Register EnsureTempRegister(); 56 57 // Return a known free register different from the given one (which could 58 // be no_reg---returning any free register), or no_reg if there is no such 59 // register. 60 Register GetFreeRegisterNot(Register reg); 61 62 // Verify that the state is the initial one, ready to resolve a single 63 // parallel move. 64 bool HasBeenReset(); 65 66 // Verify the move list before performing moves. 67 void Verify(); 68 69 LCodeGen* cgen_; 70 71 // List of moves not yet resolved. 72 ZoneList<LMoveOperands> moves_; 73 74 // Source and destination use counts for the general purpose registers. 75 int source_uses_[Register::kNumRegisters]; 76 int destination_uses_[DoubleRegister::kMaxNumRegisters]; 77 78 // If we had to spill on demand, the currently spilled register's 79 // allocation index. 80 int spilled_register_; 81 }; 82 83 } // namespace internal 84 } // namespace v8 85 86 #endif // V8_CRANKSHAFT_IA32_LITHIUM_GAP_RESOLVER_IA32_H_ 87
