js/src/jit/UnreachableCodeElimination.h@6474c204b198 (annotated)
js/src/jit/UnreachableCodeElimination.h
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- |
| michael@0 | 2 | * vim: set ts=8 sts=4 et sw=4 tw=99: |
| michael@0 | 3 | * This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 4 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 5 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 6 | |
| michael@0 | 7 | #ifndef jit_UnreachableCodeElimination_h |
| michael@0 | 8 | #define jit_UnreachableCodeElimination_h |
| michael@0 | 9 | |
| michael@0 | 10 | #include "jit/MIRGraph.h" |
| michael@0 | 11 | |
| michael@0 | 12 | namespace js { |
| michael@0 | 13 | namespace jit { |
| michael@0 | 14 | |
| michael@0 | 15 | class MIRGraph; |
| michael@0 | 16 | |
| michael@0 | 17 | class UnreachableCodeElimination |
| michael@0 | 18 | { |
| michael@0 | 19 | typedef Vector<MBasicBlock *, 16, SystemAllocPolicy> BlockList; |
| michael@0 | 20 | |
| michael@0 | 21 | MIRGenerator *mir_; |
| michael@0 | 22 | MIRGraph &graph_; |
| michael@0 | 23 | uint32_t marked_; |
| michael@0 | 24 | bool redundantPhis_; |
| michael@0 | 25 | bool rerunAliasAnalysis_; |
| michael@0 | 26 | bool disableAliasAnalysis_; |
| michael@0 | 27 | |
| michael@0 | 28 | bool prunePointlessBranchesAndMarkReachableBlocks(); |
| michael@0 | 29 | void checkDependencyAndRemoveUsesFromUnmarkedBlocks(MDefinition *instr); |
| michael@0 | 30 | bool removeUnmarkedBlocksAndClearDominators(); |
| michael@0 | 31 | bool removeUnmarkedBlocksAndCleanup(); |
| michael@0 | 32 | |
| michael@0 | 33 | bool enqueue(MBasicBlock *block, BlockList &list); |
| michael@0 | 34 | MBasicBlock *optimizableSuccessor(MBasicBlock *block); |
| michael@0 | 35 | |
| michael@0 | 36 | public: |
| michael@0 | 37 | UnreachableCodeElimination(MIRGenerator *mir, MIRGraph &graph) |
| michael@0 | 38 | : mir_(mir), |
| michael@0 | 39 | graph_(graph), |
| michael@0 | 40 | marked_(0), |
| michael@0 | 41 | redundantPhis_(false), |
| michael@0 | 42 | rerunAliasAnalysis_(false), |
| michael@0 | 43 | disableAliasAnalysis_(false) |
| michael@0 | 44 | {} |
| michael@0 | 45 | |
| michael@0 | 46 | // Walks the graph and discovers what is reachable. Removes everything else. |
| michael@0 | 47 | bool analyze(); |
| michael@0 | 48 | |
| michael@0 | 49 | // Removes any blocks that are not marked. Assumes that these blocks are not |
| michael@0 | 50 | // reachable. The parameter |marked| should be the number of blocks that |
| michael@0 | 51 | // are marked. |
| michael@0 | 52 | bool removeUnmarkedBlocks(size_t marked); |
| michael@0 | 53 | |
| michael@0 | 54 | // Call this function to prevent alias analysis to run a second time if we |
| michael@0 | 55 | // do not need it. |
| michael@0 | 56 | void disableAliasAnalysis() { |
| michael@0 | 57 | disableAliasAnalysis_ = true; |
| michael@0 | 58 | } |
| michael@0 | 59 | }; |
| michael@0 | 60 | |
| michael@0 | 61 | } /* namespace jit */ |
| michael@0 | 62 | } /* namespace js */ |
| michael@0 | 63 | |
| michael@0 | 64 | #endif /* jit_UnreachableCodeElimination_h */ |
