interpreter/Register.h

   1 /*
   2  * Copyright (C) 2008, 2009 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  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef Register_h
  30 #define Register_h
  31
  32 #include "JSCJSValue.h"
  33 #include <wtf/Assertions.h>
  34 #include <wtf/VectorTraits.h>
  35
  36 namespace JSC {
  37
  38     class CodeBlock;
  39     class ExecState;
  40     class JSActivation;
  41     class JSObject;
  42     class JSPropertyNameIterator;
  43     class JSScope;
  44
  45     typedef ExecState CallFrame;
  46
  47     class Register {
  48         WTF_MAKE_FAST_ALLOCATED;
  49     public:
  50         Register();
  51
  52         Register(const JSValue&);
  53         Register& operator=(const JSValue&);
  54         JSValue jsValue() const;
  55         EncodedJSValue encodedJSValue() const;
  56
  57         Register& operator=(CallFrame*);
  58         Register& operator=(CodeBlock*);
  59         Register& operator=(JSScope*);
  60
  61         int32_t i() const;
  62         JSActivation* activation() const;
  63         CallFrame* callFrame() const;
  64         CodeBlock* codeBlock() const;
  65         JSObject* function() const;
  66         JSPropertyNameIterator* propertyNameIterator() const;
  67         JSScope* scope() const;
  68         int32_t unboxedInt32() const;
  69         int64_t unboxedInt52() const;
  70         int64_t unboxedStrictInt52() const;
  71         bool unboxedBoolean() const;
  72         double unboxedDouble() const;
  73         JSCell* unboxedCell() const;
  74         int32_t payload() const;
  75         int32_t tag() const;
  76         int32_t& payload();
  77         int32_t& tag();
  78
  79         static Register withInt(int32_t i)
  80         {
  81             Register r = jsNumber(i);
  82             return r;
  83         }
  84
  85         static Register withCallee(JSObject* callee);
  86
  87     private:
  88         union {
  89             EncodedJSValue value;
  90             CallFrame* callFrame;
  91             CodeBlock* codeBlock;
  92             EncodedValueDescriptor encodedValue;
  93             double number;
  94             int64_t integer;
  95         } u;
  96     };
  97
  98     ALWAYS_INLINE Register::Register()
  99     {
 100 #ifndef NDEBUG
 101         *this = JSValue();
 102 #endif
 103     }
 104
 105     ALWAYS_INLINE Register::Register(const JSValue& v)
 106     {
 107         u.value = JSValue::encode(v);
 108     }
 109
 110     ALWAYS_INLINE Register& Register::operator=(const JSValue& v)
 111     {
 112         u.value = JSValue::encode(v);
 113         return *this;
 114     }
 115
 116     ALWAYS_INLINE JSValue Register::jsValue() const
 117     {
 118         return JSValue::decode(u.value);
 119     }
 120
 121     ALWAYS_INLINE EncodedJSValue Register::encodedJSValue() const
 122     {
 123         return u.value;
 124     }
 125
 126     // Interpreter functions
 127
 128     ALWAYS_INLINE Register& Register::operator=(CallFrame* callFrame)
 129     {
 130         u.callFrame = callFrame;
 131         return *this;
 132     }
 133
 134     ALWAYS_INLINE Register& Register::operator=(CodeBlock* codeBlock)
 135     {
 136         u.codeBlock = codeBlock;
 137         return *this;
 138     }
 139
 140     ALWAYS_INLINE int32_t Register::i() const
 141     {
 142         return jsValue().asInt32();
 143     }
 144
 145     ALWAYS_INLINE CallFrame* Register::callFrame() const
 146     {
 147         return u.callFrame;
 148     }
 149
 150     ALWAYS_INLINE CodeBlock* Register::codeBlock() const
 151     {
 152         return u.codeBlock;
 153     }
 154
 155     ALWAYS_INLINE int32_t Register::unboxedInt32() const
 156     {
 157         return payload();
 158     }
 159
 160     ALWAYS_INLINE int64_t Register::unboxedInt52() const
 161     {
 162         return u.integer >> JSValue::int52ShiftAmount;
 163     }
 164
 165     ALWAYS_INLINE int64_t Register::unboxedStrictInt52() const
 166     {
 167         return u.integer;
 168     }
 169
 170     ALWAYS_INLINE bool Register::unboxedBoolean() const
 171     {
 172         return !!payload();
 173     }
 174
 175     ALWAYS_INLINE double Register::unboxedDouble() const
 176     {
 177         return u.number;
 178     }
 179
 180     ALWAYS_INLINE JSCell* Register::unboxedCell() const
 181     {
 182 #if USE(JSVALUE64)
 183         return u.encodedValue.ptr;
 184 #else
 185         return bitwise_cast<JSCell*>(payload());
 186 #endif
 187     }
 188
 189     ALWAYS_INLINE int32_t Register::payload() const
 190     {
 191         return u.encodedValue.asBits.payload;
 192     }
 193
 194     ALWAYS_INLINE int32_t Register::tag() const
 195     {
 196         return u.encodedValue.asBits.tag;
 197     }
 198
 199     ALWAYS_INLINE int32_t& Register::payload()
 200     {
 201         return u.encodedValue.asBits.payload;
 202     }
 203
 204     ALWAYS_INLINE int32_t& Register::tag()
 205     {
 206         return u.encodedValue.asBits.tag;
 207     }
 208
 209 } // namespace JSC
 210
 211 namespace WTF {
 212
 213     template<> struct VectorTraits<JSC::Register> : VectorTraitsBase<true, JSC::Register> { };
 214
 215 } // namespace WTF
 216
 217 #endif // Register_h