bytecode/LazyOperandValueProfile.h

   1 /*
   2  * Copyright (C) 2012, 2013 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef LazyOperandValueProfile_h
  27 #define LazyOperandValueProfile_h
  28
  29 #include "ConcurrentJITLock.h"
  30 #include "ValueProfile.h"
  31 #include "VirtualRegister.h"
  32 #include <wtf/HashMap.h>
  33 #include <wtf/Noncopyable.h>
  34 #include <wtf/SegmentedVector.h>
  35
  36 namespace JSC {
  37
  38 class ScriptExecutable;
  39
  40 class LazyOperandValueProfileKey {
  41 public:
  42     LazyOperandValueProfileKey()
  43         : m_bytecodeOffset(0) // 0 = empty value
  44         , m_operand(VirtualRegister()) // not a valid operand index in our current scheme
  45     {
  46     }
  47
  48     LazyOperandValueProfileKey(WTF::HashTableDeletedValueType)
  49         : m_bytecodeOffset(1) // 1 = deleted value
  50         , m_operand(VirtualRegister()) // not a valid operand index in our current scheme
  51     {
  52     }
  53
  54     LazyOperandValueProfileKey(unsigned bytecodeOffset, VirtualRegister operand)
  55         : m_bytecodeOffset(bytecodeOffset)
  56         , m_operand(operand)
  57     {
  58         ASSERT(m_operand.isValid());
  59     }
  60
  61     bool operator!() const
  62     {
  63         return !m_operand.isValid();
  64     }
  65
  66     bool operator==(const LazyOperandValueProfileKey& other) const
  67     {
  68         return m_bytecodeOffset == other.m_bytecodeOffset
  69             && m_operand == other.m_operand;
  70     }
  71
  72     unsigned hash() const
  73     {
  74         return WTF::intHash(m_bytecodeOffset) + m_operand.offset();
  75     }
  76
  77     unsigned bytecodeOffset() const
  78     {
  79         ASSERT(!!*this);
  80         return m_bytecodeOffset;
  81     }
  82
  83     VirtualRegister operand() const
  84     {
  85         ASSERT(!!*this);
  86         return m_operand;
  87     }
  88
  89     bool isHashTableDeletedValue() const
  90     {
  91         return !m_operand.isValid() && m_bytecodeOffset;
  92     }
  93 private:
  94     unsigned m_bytecodeOffset;
  95     VirtualRegister m_operand;
  96 };
  97
  98 struct LazyOperandValueProfileKeyHash {
  99     static unsigned hash(const LazyOperandValueProfileKey& key) { return key.hash(); }
 100     static bool equal(
 101         const LazyOperandValueProfileKey& a,
 102         const LazyOperandValueProfileKey& b) { return a == b; }
 103     static const bool safeToCompareToEmptyOrDeleted = true;
 104 };
 105
 106 } // namespace JSC
 107
 108 namespace WTF {
 109
 110 template<typename T> struct DefaultHash;
 111 template<> struct DefaultHash<JSC::LazyOperandValueProfileKey> {
 112     typedef JSC::LazyOperandValueProfileKeyHash Hash;
 113 };
 114
 115 template<typename T> struct HashTraits;
 116 template<> struct HashTraits<JSC::LazyOperandValueProfileKey> : public GenericHashTraits<JSC::LazyOperandValueProfileKey> {
 117     static void constructDeletedValue(JSC::LazyOperandValueProfileKey& slot) { new (NotNull, &slot) JSC::LazyOperandValueProfileKey(HashTableDeletedValue); }
 118     static bool isDeletedValue(const JSC::LazyOperandValueProfileKey& value) { return value.isHashTableDeletedValue(); }
 119 };
 120
 121 } // namespace WTF
 122
 123 namespace JSC {
 124
 125 struct LazyOperandValueProfile : public MinimalValueProfile {
 126     LazyOperandValueProfile()
 127         : MinimalValueProfile()
 128         , m_operand(VirtualRegister())
 129     {
 130     }
 131
 132     explicit LazyOperandValueProfile(const LazyOperandValueProfileKey& key)
 133         : MinimalValueProfile(key.bytecodeOffset())
 134         , m_operand(key.operand())
 135     {
 136     }
 137
 138     LazyOperandValueProfileKey key() const
 139     {
 140         return LazyOperandValueProfileKey(m_bytecodeOffset, m_operand);
 141     }
 142
 143     VirtualRegister m_operand;
 144
 145     typedef SegmentedVector<LazyOperandValueProfile, 8> List;
 146 };
 147
 148 class LazyOperandValueProfileParser;
 149
 150 class CompressedLazyOperandValueProfileHolder {
 151     WTF_MAKE_NONCOPYABLE(CompressedLazyOperandValueProfileHolder);
 152 public:
 153     CompressedLazyOperandValueProfileHolder();
 154     ~CompressedLazyOperandValueProfileHolder();
 155
 156     void computeUpdatedPredictions(const ConcurrentJITLocker&);
 157
 158     LazyOperandValueProfile* add(
 159         const ConcurrentJITLocker&, const LazyOperandValueProfileKey& key);
 160
 161 private:
 162     friend class LazyOperandValueProfileParser;
 163     std::unique_ptr<LazyOperandValueProfile::List> m_data;
 164 };
 165
 166 class LazyOperandValueProfileParser {
 167     WTF_MAKE_NONCOPYABLE(LazyOperandValueProfileParser);
 168 public:
 169     explicit LazyOperandValueProfileParser();
 170     ~LazyOperandValueProfileParser();
 171
 172     void initialize(
 173         const ConcurrentJITLocker&, CompressedLazyOperandValueProfileHolder& holder);
 174
 175     LazyOperandValueProfile* getIfPresent(
 176         const LazyOperandValueProfileKey& key) const;
 177
 178     SpeculatedType prediction(
 179         const ConcurrentJITLocker&, const LazyOperandValueProfileKey& key) const;
 180 private:
 181     HashMap<LazyOperandValueProfileKey, LazyOperandValueProfile*> m_map;
 182 };
 183
 184 } // namespace JSC
 185
 186 #endif // LazyOperandValueProfile_h
 187
 188