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 JSLexicalEnvironment;
  41     class JSObject;
  42     class JSScope;
  43
  44     typedef ExecState CallFrame;
  45
  46     class Register {
  47         WTF_MAKE_FAST_ALLOCATED;
  48     public:
  49         Register();
  50
  51         Register(const JSValue&);
  52         Register& operator=(const JSValue&);
  53         JSValue jsValue() const;
  54         EncodedJSValue encodedJSValue() const;
  55
  56         Register& operator=(CallFrame*);
  57         Register& operator=(CodeBlock*);
  58         Register& operator=(JSScope*);
  59         Register& operator=(JSObject*);
  60
  61         int32_t i() const;
  62         JSLexicalEnvironment* lexicalEnvironment() const;
  63         CallFrame* callFrame() const;
  64         CodeBlock* codeBlock() const;
  65         JSObject* object() const;
  66         JSScope* scope() const;
  67         int32_t unboxedInt32() const;
  68         int64_t unboxedInt52() const;
  69         int64_t unboxedStrictInt52() const;
  70         bool unboxedBoolean() const;
  71         double unboxedDouble() const;
  72         JSCell* unboxedCell() const;
  73         int32_t payload() const;
  74         int32_t tag() const;
  75         int32_t& payload();
  76         int32_t& tag();
  77
  78         static Register withInt(int32_t i)
  79         {
  80             Register r = jsNumber(i);
  81             return r;
  82         }
  83
  84     private:
  85         union {
  86             EncodedJSValue value;
  87             CallFrame* callFrame;
  88             CodeBlock* codeBlock;
  89             EncodedValueDescriptor encodedValue;
  90             double number;
  91             int64_t integer;
  92         } u;
  93     };
  94
  95     ALWAYS_INLINE Register::Register()
  96     {
  97 #ifndef NDEBUG
  98         *this = JSValue();
  99 #endif
 100     }
 101
 102     ALWAYS_INLINE Register::Register(const JSValue& v)
 103     {
 104         u.value = JSValue::encode(v);
 105     }
 106
 107     ALWAYS_INLINE Register& Register::operator=(const JSValue& v)
 108     {
 109         u.value = JSValue::encode(v);
 110         return *this;
 111     }
 112
 113     ALWAYS_INLINE JSValue Register::jsValue() const
 114     {
 115         return JSValue::decode(u.value);
 116     }
 117
 118     ALWAYS_INLINE EncodedJSValue Register::encodedJSValue() const
 119     {
 120         return u.value;
 121     }
 122
 123     // Interpreter functions
 124
 125     ALWAYS_INLINE Register& Register::operator=(CallFrame* callFrame)
 126     {
 127         u.callFrame = callFrame;
 128         return *this;
 129     }
 130
 131     ALWAYS_INLINE Register& Register::operator=(CodeBlock* codeBlock)
 132     {
 133         u.codeBlock = codeBlock;
 134         return *this;
 135     }
 136
 137     ALWAYS_INLINE int32_t Register::i() const
 138     {
 139         return jsValue().asInt32();
 140     }
 141
 142     ALWAYS_INLINE CallFrame* Register::callFrame() const
 143     {
 144         return u.callFrame;
 145     }
 146
 147     ALWAYS_INLINE CodeBlock* Register::codeBlock() const
 148     {
 149         return u.codeBlock;
 150     }
 151
 152     ALWAYS_INLINE int32_t Register::unboxedInt32() const
 153     {
 154         return payload();
 155     }
 156
 157     ALWAYS_INLINE int64_t Register::unboxedInt52() const
 158     {
 159         return u.integer >> JSValue::int52ShiftAmount;
 160     }
 161
 162     ALWAYS_INLINE int64_t Register::unboxedStrictInt52() const
 163     {
 164         return u.integer;
 165     }
 166
 167     ALWAYS_INLINE bool Register::unboxedBoolean() const
 168     {
 169         return !!payload();
 170     }
 171
 172     ALWAYS_INLINE double Register::unboxedDouble() const
 173     {
 174         return u.number;
 175     }
 176
 177     ALWAYS_INLINE JSCell* Register::unboxedCell() const
 178     {
 179 #if USE(JSVALUE64)
 180         return u.encodedValue.ptr;
 181 #else
 182         return bitwise_cast<JSCell*>(payload());
 183 #endif
 184     }
 185
 186     ALWAYS_INLINE int32_t Register::payload() const
 187     {
 188         return u.encodedValue.asBits.payload;
 189     }
 190
 191     ALWAYS_INLINE int32_t Register::tag() const
 192     {
 193         return u.encodedValue.asBits.tag;
 194     }
 195
 196     ALWAYS_INLINE int32_t& Register::payload()
 197     {
 198         return u.encodedValue.asBits.payload;
 199     }
 200
 201     ALWAYS_INLINE int32_t& Register::tag()
 202     {
 203         return u.encodedValue.asBits.tag;
 204     }
 205
 206 } // namespace JSC
 207
 208 namespace WTF {
 209
 210     template<> struct VectorTraits<JSC::Register> : VectorTraitsBase<true, JSC::Register> { };
 211
 212 } // namespace WTF
 213
 214 #endif // Register_h