bytecode/DataFormat.h

   1 /*
   2  * Copyright (C) 2011 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 DataFormat_h
  27 #define DataFormat_h
  28
  29 #include <wtf/Assertions.h>
  30
  31 namespace JSC {
  32
  33 // === DataFormat ===
  34 //
  35 // This enum tracks the current representation in which a value is being held.
  36 // Values may be unboxed primitives (int32, double, or cell), or boxed as a JSValue.
  37 // For boxed values, we may know the type of boxing that has taken place.
  38 // (May also need bool, array, object, string types!)
  39 enum DataFormat {
  40     DataFormatNone = 0,
  41     DataFormatInteger = 1,
  42     DataFormatDouble = 2,
  43     DataFormatBoolean = 3,
  44     DataFormatCell = 4,
  45     DataFormatStorage = 5,
  46     DataFormatJS = 8,
  47     DataFormatJSInteger = DataFormatJS | DataFormatInteger,
  48     DataFormatJSDouble = DataFormatJS | DataFormatDouble,
  49     DataFormatJSCell = DataFormatJS | DataFormatCell,
  50     DataFormatJSBoolean = DataFormatJS | DataFormatBoolean,
  51
  52     // Marker deliminating ordinary data formats and OSR-only data formats.
  53     DataFormatOSRMarker = 32,
  54
  55     // Special data formats used only for OSR.
  56     DataFormatDead = 33, // Implies jsUndefined().
  57     DataFormatArguments = 34 // Implies that the arguments object must be reified.
  58 };
  59
  60 inline const char* dataFormatToString(DataFormat dataFormat)
  61 {
  62     switch (dataFormat) {
  63     case DataFormatNone:
  64         return "None";
  65     case DataFormatInteger:
  66         return "Integer";
  67     case DataFormatDouble:
  68         return "Double";
  69     case DataFormatCell:
  70         return "Cell";
  71     case DataFormatBoolean:
  72         return "Boolean";
  73     case DataFormatStorage:
  74         return "Storage";
  75     case DataFormatJS:
  76         return "JS";
  77     case DataFormatJSInteger:
  78         return "JSInteger";
  79     case DataFormatJSDouble:
  80         return "JSDouble";
  81     case DataFormatJSCell:
  82         return "JSCell";
  83     case DataFormatJSBoolean:
  84         return "JSBoolean";
  85     case DataFormatDead:
  86         return "Dead";
  87     case DataFormatArguments:
  88         return "Arguments";
  89     default:
  90         RELEASE_ASSERT_NOT_REACHED();
  91         return "Unknown";
  92     }
  93 }
  94
  95 #if USE(JSVALUE64)
  96 inline bool needDataFormatConversion(DataFormat from, DataFormat to)
  97 {
  98     ASSERT(from != DataFormatNone);
  99     ASSERT(to != DataFormatNone);
 100     switch (from) {
 101     case DataFormatInteger:
 102     case DataFormatDouble:
 103         return to != from;
 104     case DataFormatCell:
 105     case DataFormatJS:
 106     case DataFormatJSInteger:
 107     case DataFormatJSDouble:
 108     case DataFormatJSCell:
 109     case DataFormatJSBoolean:
 110         switch (to) {
 111         case DataFormatInteger:
 112         case DataFormatDouble:
 113             return true;
 114         case DataFormatCell:
 115         case DataFormatJS:
 116         case DataFormatJSInteger:
 117         case DataFormatJSDouble:
 118         case DataFormatJSCell:
 119         case DataFormatJSBoolean:
 120             return false;
 121         default:
 122             // This captures DataFormatBoolean, which is currently unused.
 123             RELEASE_ASSERT_NOT_REACHED();
 124         }
 125     case DataFormatStorage:
 126         ASSERT(to == DataFormatStorage);
 127         return false;
 128     default:
 129         // This captures DataFormatBoolean, which is currently unused.
 130         RELEASE_ASSERT_NOT_REACHED();
 131     }
 132     return true;
 133 }
 134
 135 #elif USE(JSVALUE32_64)
 136 inline bool needDataFormatConversion(DataFormat from, DataFormat to)
 137 {
 138     ASSERT(from != DataFormatNone);
 139     ASSERT(to != DataFormatNone);
 140     switch (from) {
 141     case DataFormatInteger:
 142     case DataFormatCell:
 143     case DataFormatBoolean:
 144         return ((to & DataFormatJS) || to == DataFormatDouble);
 145     case DataFormatDouble:
 146     case DataFormatJSDouble:
 147         return (to != DataFormatDouble && to != DataFormatJSDouble);
 148     case DataFormatJS:
 149     case DataFormatJSInteger:
 150     case DataFormatJSCell:
 151     case DataFormatJSBoolean:
 152         return (!(to & DataFormatJS) || to == DataFormatJSDouble);
 153     case DataFormatStorage:
 154         ASSERT(to == DataFormatStorage);
 155         return false;
 156     default:
 157         RELEASE_ASSERT_NOT_REACHED();
 158     }
 159     return true;
 160 }
 161 #endif
 162
 163 inline bool isJSFormat(DataFormat format, DataFormat expectedFormat)
 164 {
 165     ASSERT(expectedFormat & DataFormatJS);
 166     return (format | DataFormatJS) == expectedFormat;
 167 }
 168
 169 inline bool isJSInteger(DataFormat format)
 170 {
 171     return isJSFormat(format, DataFormatJSInteger);
 172 }
 173
 174 inline bool isJSDouble(DataFormat format)
 175 {
 176     return isJSFormat(format, DataFormatJSDouble);
 177 }
 178
 179 inline bool isJSCell(DataFormat format)
 180 {
 181     return isJSFormat(format, DataFormatJSCell);
 182 }
 183
 184 inline bool isJSBoolean(DataFormat format)
 185 {
 186     return isJSFormat(format, DataFormatJSBoolean);
 187 }
 188
 189 }
 190
 191 #endif // DataFormat_h