1 // Copyright 2012 the V8 project authors. All rights reserved. 2 // Redistribution and use in source and binary forms, with or without 3 // modification, are permitted provided that the following conditions are 4 // met: 5 // 6 // * Redistributions of source code must retain the above copyright 7 // notice, this list of conditions and the following disclaimer. 8 // * Redistributions in binary form must reproduce the above 9 // copyright notice, this list of conditions and the following 10 // disclaimer in the documentation and/or other materials provided 11 // with the distribution. 12 // * Neither the name of Google Inc. nor the names of its 13 // contributors may be used to endorse or promote products derived 14 // from this software without specific prior written permission. 15 // 16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28 #ifndef V8_ELEMENTS_KIND_H_ 29 #define V8_ELEMENTS_KIND_H_ 30 31 #include "v8checks.h" 32 33 namespace v8 { 34 namespace internal { 35 36 enum ElementsKind { 37 // The "fast" kind for elements that only contain SMI values. Must be first 38 // to make it possible to efficiently check maps for this kind. 39 FAST_SMI_ELEMENTS, 40 FAST_HOLEY_SMI_ELEMENTS, 41 42 // The "fast" kind for tagged values. Must be second to make it possible to 43 // efficiently check maps for this and the FAST_SMI_ONLY_ELEMENTS kind 44 // together at once. 45 FAST_ELEMENTS, 46 FAST_HOLEY_ELEMENTS, 47 48 // The "fast" kind for unwrapped, non-tagged double values. 49 FAST_DOUBLE_ELEMENTS, 50 FAST_HOLEY_DOUBLE_ELEMENTS, 51 52 // The "slow" kind. 53 DICTIONARY_ELEMENTS, 54 NON_STRICT_ARGUMENTS_ELEMENTS, 55 // The "fast" kind for external arrays 56 EXTERNAL_BYTE_ELEMENTS, 57 EXTERNAL_UNSIGNED_BYTE_ELEMENTS, 58 EXTERNAL_SHORT_ELEMENTS, 59 EXTERNAL_UNSIGNED_SHORT_ELEMENTS, 60 EXTERNAL_INT_ELEMENTS, 61 EXTERNAL_UNSIGNED_INT_ELEMENTS, 62 EXTERNAL_FLOAT_ELEMENTS, 63 EXTERNAL_DOUBLE_ELEMENTS, 64 EXTERNAL_PIXEL_ELEMENTS, 65 66 // Derived constants from ElementsKind 67 FIRST_ELEMENTS_KIND = FAST_SMI_ELEMENTS, 68 LAST_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS, 69 FIRST_FAST_ELEMENTS_KIND = FAST_SMI_ELEMENTS, 70 LAST_FAST_ELEMENTS_KIND = FAST_HOLEY_DOUBLE_ELEMENTS, 71 FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_BYTE_ELEMENTS, 72 LAST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS, 73 TERMINAL_FAST_ELEMENTS_KIND = FAST_HOLEY_ELEMENTS 74 }; 75 76 const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1; 77 const int kFastElementsKindCount = LAST_FAST_ELEMENTS_KIND - 78 FIRST_FAST_ELEMENTS_KIND + 1; 79 80 // The number to add to a packed elements kind to reach a holey elements kind 81 const int kFastElementsKindPackedToHoley = 82 FAST_HOLEY_SMI_ELEMENTS - FAST_SMI_ELEMENTS; 83 84 int ElementsKindToShiftSize(ElementsKind elements_kind); 85 const char* ElementsKindToString(ElementsKind kind); 86 void PrintElementsKind(FILE* out, ElementsKind kind); 87 88 ElementsKind GetInitialFastElementsKind(); 89 90 ElementsKind GetFastElementsKindFromSequenceIndex(int sequence_index); 91 92 int GetSequenceIndexFromFastElementsKind(ElementsKind elements_kind); 93 94 95 inline bool IsDictionaryElementsKind(ElementsKind kind) { 96 return kind == DICTIONARY_ELEMENTS; 97 } 98 99 100 inline bool IsExternalArrayElementsKind(ElementsKind kind) { 101 return kind >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND && 102 kind <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND; 103 } 104 105 106 inline bool IsFastElementsKind(ElementsKind kind) { 107 ASSERT(FIRST_FAST_ELEMENTS_KIND == 0); 108 return kind <= FAST_HOLEY_DOUBLE_ELEMENTS; 109 } 110 111 112 inline bool IsFastDoubleElementsKind(ElementsKind kind) { 113 return kind == FAST_DOUBLE_ELEMENTS || 114 kind == FAST_HOLEY_DOUBLE_ELEMENTS; 115 } 116 117 118 inline bool IsExternalFloatOrDoubleElementsKind(ElementsKind kind) { 119 return kind == EXTERNAL_DOUBLE_ELEMENTS || 120 kind == EXTERNAL_FLOAT_ELEMENTS; 121 } 122 123 124 inline bool IsDoubleOrFloatElementsKind(ElementsKind kind) { 125 return IsFastDoubleElementsKind(kind) || 126 IsExternalFloatOrDoubleElementsKind(kind); 127 } 128 129 130 inline bool IsFastSmiOrObjectElementsKind(ElementsKind kind) { 131 return kind == FAST_SMI_ELEMENTS || 132 kind == FAST_HOLEY_SMI_ELEMENTS || 133 kind == FAST_ELEMENTS || 134 kind == FAST_HOLEY_ELEMENTS; 135 } 136 137 138 inline bool IsFastSmiElementsKind(ElementsKind kind) { 139 return kind == FAST_SMI_ELEMENTS || 140 kind == FAST_HOLEY_SMI_ELEMENTS; 141 } 142 143 144 inline bool IsFastObjectElementsKind(ElementsKind kind) { 145 return kind == FAST_ELEMENTS || 146 kind == FAST_HOLEY_ELEMENTS; 147 } 148 149 150 inline bool IsFastHoleyElementsKind(ElementsKind kind) { 151 return kind == FAST_HOLEY_SMI_ELEMENTS || 152 kind == FAST_HOLEY_DOUBLE_ELEMENTS || 153 kind == FAST_HOLEY_ELEMENTS; 154 } 155 156 157 inline bool IsHoleyElementsKind(ElementsKind kind) { 158 return IsFastHoleyElementsKind(kind) || 159 kind == DICTIONARY_ELEMENTS; 160 } 161 162 163 inline bool IsFastPackedElementsKind(ElementsKind kind) { 164 return kind == FAST_SMI_ELEMENTS || 165 kind == FAST_DOUBLE_ELEMENTS || 166 kind == FAST_ELEMENTS; 167 } 168 169 170 inline ElementsKind GetPackedElementsKind(ElementsKind holey_kind) { 171 if (holey_kind == FAST_HOLEY_SMI_ELEMENTS) { 172 return FAST_SMI_ELEMENTS; 173 } 174 if (holey_kind == FAST_HOLEY_DOUBLE_ELEMENTS) { 175 return FAST_DOUBLE_ELEMENTS; 176 } 177 if (holey_kind == FAST_HOLEY_ELEMENTS) { 178 return FAST_ELEMENTS; 179 } 180 return holey_kind; 181 } 182 183 184 inline ElementsKind GetHoleyElementsKind(ElementsKind packed_kind) { 185 if (packed_kind == FAST_SMI_ELEMENTS) { 186 return FAST_HOLEY_SMI_ELEMENTS; 187 } 188 if (packed_kind == FAST_DOUBLE_ELEMENTS) { 189 return FAST_HOLEY_DOUBLE_ELEMENTS; 190 } 191 if (packed_kind == FAST_ELEMENTS) { 192 return FAST_HOLEY_ELEMENTS; 193 } 194 return packed_kind; 195 } 196 197 198 inline ElementsKind FastSmiToObjectElementsKind(ElementsKind from_kind) { 199 ASSERT(IsFastSmiElementsKind(from_kind)); 200 return (from_kind == FAST_SMI_ELEMENTS) 201 ? FAST_ELEMENTS 202 : FAST_HOLEY_ELEMENTS; 203 } 204 205 206 inline bool IsSimpleMapChangeTransition(ElementsKind from_kind, 207 ElementsKind to_kind) { 208 return (GetHoleyElementsKind(from_kind) == to_kind) || 209 (IsFastSmiElementsKind(from_kind) && 210 IsFastObjectElementsKind(to_kind)); 211 } 212 213 214 bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind, 215 ElementsKind to_kind); 216 217 218 inline bool IsTransitionableFastElementsKind(ElementsKind from_kind) { 219 return IsFastElementsKind(from_kind) && 220 from_kind != TERMINAL_FAST_ELEMENTS_KIND; 221 } 222 223 224 ElementsKind GetNextMoreGeneralFastElementsKind(ElementsKind elements_kind, 225 bool allow_only_packed); 226 227 228 inline bool CanTransitionToMoreGeneralFastElementsKind( 229 ElementsKind elements_kind, 230 bool allow_only_packed) { 231 return IsFastElementsKind(elements_kind) && 232 (elements_kind != TERMINAL_FAST_ELEMENTS_KIND && 233 (!allow_only_packed || elements_kind != FAST_ELEMENTS)); 234 } 235 236 237 } } // namespace v8::internal 238 239 #endif // V8_ELEMENTS_KIND_H_ 240
