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comparison: js/src/jit/ValueNumbering.h
js/src/jit/ValueNumbering.h
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| -1:000000000000 | 0:41bce5b43e40 |
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| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- | |
| 2 * vim: set ts=8 sts=4 et sw=4 tw=99: | |
| 3 * This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 #ifndef jit_ValueNumbering_h | |
| 8 #define jit_ValueNumbering_h | |
| 9 | |
| 10 #include "jit/MIR.h" | |
| 11 | |
| 12 namespace js { | |
| 13 namespace jit { | |
| 14 | |
| 15 class ValueNumberer | |
| 16 { | |
| 17 protected: | |
| 18 struct ValueHasher | |
| 19 { | |
| 20 typedef MDefinition * Lookup; | |
| 21 typedef MDefinition * Key; | |
| 22 static HashNumber hash(const Lookup &ins) { | |
| 23 return ins->valueHash(); | |
| 24 } | |
| 25 | |
| 26 static bool match(const Key &k, const Lookup &l) { | |
| 27 // If one of the instructions depends on a store, and the | |
| 28 // other instruction does not depend on the same store, | |
| 29 // the instructions are not congruent. | |
| 30 if (k->dependency() != l->dependency()) | |
| 31 return false; | |
| 32 return k->congruentTo(l); | |
| 33 } | |
| 34 }; | |
| 35 | |
| 36 typedef HashMap<MDefinition *, | |
| 37 uint32_t, | |
| 38 ValueHasher, | |
| 39 IonAllocPolicy> ValueMap; | |
| 40 | |
| 41 struct DominatingValue | |
| 42 { | |
| 43 MDefinition *def; | |
| 44 uint32_t validUntil; | |
| 45 }; | |
| 46 | |
| 47 typedef HashMap<uint32_t, | |
| 48 DominatingValue, | |
| 49 DefaultHasher<uint32_t>, | |
| 50 IonAllocPolicy> InstructionMap; | |
| 51 | |
| 52 protected: | |
| 53 TempAllocator &alloc() const; | |
| 54 uint32_t lookupValue(MDefinition *ins); | |
| 55 MDefinition *findDominatingDef(InstructionMap &defs, MDefinition *ins, size_t index); | |
| 56 | |
| 57 MDefinition *simplify(MDefinition *def, bool useValueNumbers); | |
| 58 MControlInstruction *simplifyControlInstruction(MControlInstruction *def); | |
| 59 bool eliminateRedundancies(); | |
| 60 | |
| 61 bool computeValueNumbers(); | |
| 62 | |
| 63 inline bool isMarked(MDefinition *def) { | |
| 64 return pessimisticPass_ || def->isInWorklist(); | |
| 65 } | |
| 66 | |
| 67 void markDefinition(MDefinition *def); | |
| 68 void unmarkDefinition(MDefinition *def); | |
| 69 | |
| 70 void markConsumers(MDefinition *def); | |
| 71 void markBlock(MBasicBlock *block); | |
| 72 void setClass(MDefinition *toSet, MDefinition *representative); | |
| 73 | |
| 74 public: | |
| 75 static MDefinition *findSplit(MDefinition *); | |
| 76 void breakClass(MDefinition*); | |
| 77 | |
| 78 protected: | |
| 79 MIRGenerator *mir; | |
| 80 MIRGraph &graph_; | |
| 81 ValueMap values; | |
| 82 bool pessimisticPass_; | |
| 83 size_t count_; | |
| 84 | |
| 85 public: | |
| 86 ValueNumberer(MIRGenerator *mir, MIRGraph &graph, bool optimistic); | |
| 87 bool analyze(); | |
| 88 bool clear(); | |
| 89 }; | |
| 90 | |
| 91 class ValueNumberData : public TempObject { | |
| 92 | |
| 93 friend void ValueNumberer::breakClass(MDefinition*); | |
| 94 friend MDefinition *ValueNumberer::findSplit(MDefinition*); | |
| 95 uint32_t number; | |
| 96 MDefinition *classNext; | |
| 97 MDefinition *classPrev; | |
| 98 | |
| 99 public: | |
| 100 ValueNumberData() : number(0), classNext(nullptr), classPrev(nullptr) {} | |
| 101 | |
| 102 void setValueNumber(uint32_t number_) { | |
| 103 number = number_; | |
| 104 } | |
| 105 | |
| 106 uint32_t valueNumber() { | |
| 107 return number; | |
| 108 } | |
| 109 // Set the class of this to the given representative value. | |
| 110 void setClass(MDefinition *thisDef, MDefinition *rep) { | |
| 111 JS_ASSERT(thisDef->valueNumberData() == this); | |
| 112 // If we are attempting to insert ourself, then nothing needs to be done. | |
| 113 // However, if the definition to be inserted already has the correct value number, | |
| 114 // it still needs to be inserted, since the value number needs to be updated lazily. | |
| 115 // this updating tactic can leave the world in a state where thisDef is not in the | |
| 116 // equivalence class of rep, but it has the same value number. Defs in this state | |
| 117 // need to be re-processed. | |
| 118 if (this == rep->valueNumberData()) | |
| 119 return; | |
| 120 | |
| 121 if (classNext) | |
| 122 classNext->valueNumberData()->classPrev = classPrev; | |
| 123 if (classPrev) | |
| 124 classPrev->valueNumberData()->classNext = classNext; | |
| 125 | |
| 126 | |
| 127 classPrev = rep; | |
| 128 classNext = rep->valueNumberData()->classNext; | |
| 129 | |
| 130 if (rep->valueNumberData()->classNext) | |
| 131 rep->valueNumberData()->classNext->valueNumberData()->classPrev = thisDef; | |
| 132 rep->valueNumberData()->classNext = thisDef; | |
| 133 } | |
| 134 }; | |
| 135 } // namespace jit | |
| 136 } // namespace js | |
| 137 | |
| 138 #endif /* jit_ValueNumbering_h */ |
