Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 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_ARM_LITHIUM_GAP_RESOLVER_ARM_H_ |
| 6 | #define V8_CRANKSHAFT_ARM_LITHIUM_GAP_RESOLVER_ARM_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 | // If a cycle is found in the series of moves, save the blocking value to |
| 32 | // a scratch register. The cycle must be found by hitting the root of the |
| 33 | // depth-first search. |
| 34 | void BreakCycle(int index); |
| 35 | |
| 36 | // After a cycle has been resolved, restore the value from the scratch |
| 37 | // register to its proper destination. |
| 38 | void RestoreValue(); |
| 39 | |
| 40 | // Emit a move and remove it from the move graph. |
| 41 | void EmitMove(int index); |
| 42 | |
| 43 | // Verify the move list before performing moves. |
| 44 | void Verify(); |
| 45 | |
| 46 | LCodeGen* cgen_; |
| 47 | |
| 48 | // List of moves not yet resolved. |
| 49 | ZoneList<LMoveOperands> moves_; |
| 50 | |
| 51 | int root_index_; |
| 52 | bool in_cycle_; |
| 53 | LOperand* saved_destination_; |
| 54 | |
| 55 | // We use the root register as a scratch in a few places. When that happens, |
| 56 | // this flag is set to indicate that it needs to be restored. |
| 57 | bool need_to_restore_root_; |
| 58 | }; |
| 59 | |
| 60 | } // namespace internal |
| 61 | } // namespace v8 |
| 62 | |
| 63 | #endif // V8_CRANKSHAFT_ARM_LITHIUM_GAP_RESOLVER_ARM_H_ |