1 // Copyright 2011 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 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 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::kNumAllocatableRegisters]; 101 int destination_uses_[Register::kNumAllocatableRegisters]; 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_ 111