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/OwnPtr.h>
  35 #include <wtf/SegmentedVector.h>
  36
  37 namespace JSC {
  38
  39 class ScriptExecutable;
  40
  41 class LazyOperandValueProfileKey {
  42 public:
  43     LazyOperandValueProfileKey()
  44         : m_bytecodeOffset(0) // 0 = empty value
  45         , m_operand(VirtualRegister()) // not a valid operand index in our current scheme
  46     {
  47     }
  48
  49     LazyOperandValueProfileKey(WTF::HashTableDeletedValueType)
  50         : m_bytecodeOffset(1) // 1 = deleted value
  51         , m_operand(VirtualRegister()) // not a valid operand index in our current scheme
  52     {
  53     }
  54
  55     LazyOperandValueProfileKey(unsigned bytecodeOffset, VirtualRegister operand)
  56         : m_bytecodeOffset(bytecodeOffset)
  57         , m_operand(operand)
  58     {
  59         ASSERT(m_operand.isValid());
  60     }
  61
  62     bool operator!() const
  63     {
  64         return !m_operand.isValid();
  65     }
  66
  67     bool operator==(const LazyOperandValueProfileKey& other) const
  68     {
  69         return m_bytecodeOffset == other.m_bytecodeOffset
  70             && m_operand == other.m_operand;
  71     }
  72
  73     unsigned hash() const
  74     {
  75         return WTF::intHash(m_bytecodeOffset) + m_operand.offset();
  76     }
  77
  78     unsigned bytecodeOffset() const
  79     {
  80         ASSERT(!!*this);
  81         return m_bytecodeOffset;
  82     }
  83
  84     VirtualRegister operand() const
  85     {
  86         ASSERT(!!*this);
  87         return m_operand;
  88     }
  89
  90     bool isHashTableDeletedValue() const
  91     {
  92         return !m_operand.isValid() && m_bytecodeOffset;
  93     }
  94 private:
  95     unsigned m_bytecodeOffset;
  96     VirtualRegister m_operand;
  97 };
  98
  99 struct LazyOperandValueProfileKeyHash {
 100     static unsigned hash(const LazyOperandValueProfileKey& key) { return key.hash(); }
 101     static bool equal(
 102         const LazyOperandValueProfileKey& a,
 103         const LazyOperandValueProfileKey& b) { return a == b; }
 104     static const bool safeToCompareToEmptyOrDeleted = true;
 105 };
 106
 107 } // namespace JSC
 108
 109 namespace WTF {
 110
 111 template<typename T> struct DefaultHash;
 112 template<> struct DefaultHash<JSC::LazyOperandValueProfileKey> {
 113     typedef JSC::LazyOperandValueProfileKeyHash Hash;
 114 };
 115
 116 template<typename T> struct HashTraits;
 117 template<> struct HashTraits<JSC::LazyOperandValueProfileKey> : public GenericHashTraits<JSC::LazyOperandValueProfileKey> {
 118     static void constructDeletedValue(JSC::LazyOperandValueProfileKey& slot) { new (NotNull, &slot) JSC::LazyOperandValueProfileKey(HashTableDeletedValue); }
 119     static bool isDeletedValue(const JSC::LazyOperandValueProfileKey& value) { return value.isHashTableDeletedValue(); }
 120 };
 121
 122 } // namespace WTF
 123
 124 namespace JSC {
 125
 126 struct LazyOperandValueProfile : public MinimalValueProfile {
 127     LazyOperandValueProfile()
 128         : MinimalValueProfile()
 129         , m_operand(VirtualRegister())
 130     {
 131     }
 132
 133     explicit LazyOperandValueProfile(const LazyOperandValueProfileKey& key)
 134         : MinimalValueProfile(key.bytecodeOffset())
 135         , m_operand(key.operand())
 136     {
 137     }
 138
 139     LazyOperandValueProfileKey key() const
 140     {
 141         return LazyOperandValueProfileKey(m_bytecodeOffset, m_operand);
 142     }
 143
 144     VirtualRegister m_operand;
 145
 146     typedef SegmentedVector<LazyOperandValueProfile, 8> List;
 147 };
 148
 149 class LazyOperandValueProfileParser;
 150
 151 class CompressedLazyOperandValueProfileHolder {
 152     WTF_MAKE_NONCOPYABLE(CompressedLazyOperandValueProfileHolder);
 153 public:
 154     CompressedLazyOperandValueProfileHolder();
 155     ~CompressedLazyOperandValueProfileHolder();
 156
 157     void computeUpdatedPredictions(const ConcurrentJITLocker&);
 158
 159     LazyOperandValueProfile* add(
 160         const ConcurrentJITLocker&, const LazyOperandValueProfileKey& key);
 161
 162 private:
 163     friend class LazyOperandValueProfileParser;
 164     OwnPtr<LazyOperandValueProfile::List> m_data;
 165 };
 166
 167 class LazyOperandValueProfileParser {
 168     WTF_MAKE_NONCOPYABLE(LazyOperandValueProfileParser);
 169 public:
 170     explicit LazyOperandValueProfileParser();
 171     ~LazyOperandValueProfileParser();
 172
 173     void initialize(
 174         const ConcurrentJITLocker&, CompressedLazyOperandValueProfileHolder& holder);
 175
 176     LazyOperandValueProfile* getIfPresent(
 177         const LazyOperandValueProfileKey& key) const;
 178
 179     SpeculatedType prediction(
 180         const ConcurrentJITLocker&, const LazyOperandValueProfileKey& key) const;
 181 private:
 182     HashMap<LazyOperandValueProfileKey, LazyOperandValueProfile*> m_map;
 183 };
 184
 185 } // namespace JSC
 186
 187 #endif // LazyOperandValueProfile_h
 188
 189