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
  53 inline const char* dataFormatToString(DataFormat dataFormat)
  54 {
  55     switch (dataFormat) {
  56     case DataFormatNone:
  57         return "None";
  58     case DataFormatInteger:
  59         return "Integer";
  60     case DataFormatDouble:
  61         return "Double";
  62     case DataFormatCell:
  63         return "Cell";
  64     case DataFormatBoolean:
  65         return "Boolean";
  66     case DataFormatStorage:
  67         return "Storage";
  68     case DataFormatJS:
  69         return "JS";
  70     case DataFormatJSInteger:
  71         return "JSInteger";
  72     case DataFormatJSDouble:
  73         return "JSDouble";
  74     case DataFormatJSCell:
  75         return "JSCell";
  76     case DataFormatJSBoolean:
  77         return "JSBoolean";
  78     default:
  79         return "Unknown";
  80     }
  81 }
  82
  83 #if USE(JSVALUE64)
  84 inline bool needDataFormatConversion(DataFormat from, DataFormat to)
  85 {
  86     ASSERT(from != DataFormatNone);
  87     ASSERT(to != DataFormatNone);
  88     switch (from) {
  89     case DataFormatInteger:
  90     case DataFormatDouble:
  91         return to != from;
  92     case DataFormatCell:
  93     case DataFormatJS:
  94     case DataFormatJSInteger:
  95     case DataFormatJSDouble:
  96     case DataFormatJSCell:
  97     case DataFormatJSBoolean:
  98         switch (to) {
  99         case DataFormatInteger:
 100         case DataFormatDouble:
 101             return true;
 102         case DataFormatCell:
 103         case DataFormatJS:
 104         case DataFormatJSInteger:
 105         case DataFormatJSDouble:
 106         case DataFormatJSCell:
 107         case DataFormatJSBoolean:
 108             return false;
 109         default:
 110             // This captures DataFormatBoolean, which is currently unused.
 111             ASSERT_NOT_REACHED();
 112         }
 113     case DataFormatStorage:
 114         ASSERT(to == DataFormatStorage);
 115         return false;
 116     default:
 117         // This captures DataFormatBoolean, which is currently unused.
 118         ASSERT_NOT_REACHED();
 119     }
 120     return true;
 121 }
 122
 123 #elif USE(JSVALUE32_64)
 124 inline bool needDataFormatConversion(DataFormat from, DataFormat to)
 125 {
 126     ASSERT(from != DataFormatNone);
 127     ASSERT(to != DataFormatNone);
 128     switch (from) {
 129     case DataFormatInteger:
 130     case DataFormatCell:
 131     case DataFormatBoolean:
 132         return ((to & DataFormatJS) || to == DataFormatDouble);
 133     case DataFormatDouble:
 134     case DataFormatJSDouble:
 135         return (to != DataFormatDouble && to != DataFormatJSDouble);
 136     case DataFormatJS:
 137     case DataFormatJSInteger:
 138     case DataFormatJSCell:
 139     case DataFormatJSBoolean:
 140         return (!(to & DataFormatJS) || to == DataFormatJSDouble);
 141     case DataFormatStorage:
 142         ASSERT(to == DataFormatStorage);
 143         return false;
 144     default:
 145         ASSERT_NOT_REACHED();
 146     }
 147     return true;
 148 }
 149 #endif
 150
 151 inline bool isJSFormat(DataFormat format, DataFormat expectedFormat)
 152 {
 153     ASSERT(expectedFormat & DataFormatJS);
 154     return (format | DataFormatJS) == expectedFormat;
 155 }
 156
 157 inline bool isJSInteger(DataFormat format)
 158 {
 159     return isJSFormat(format, DataFormatJSInteger);
 160 }
 161
 162 inline bool isJSDouble(DataFormat format)
 163 {
 164     return isJSFormat(format, DataFormatJSDouble);
 165 }
 166
 167 inline bool isJSCell(DataFormat format)
 168 {
 169     return isJSFormat(format, DataFormatJSCell);
 170 }
 171
 172 inline bool isJSBoolean(DataFormat format)
 173 {
 174     return isJSFormat(format, DataFormatJSBoolean);
 175 }
 176
 177 }
 178
 179 #endif // DataFormat_h