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 33namespace v8 { 34namespace internal { 35 36enum 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 76const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1; 77const 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 81const int kFastElementsKindPackedToHoley = 82 FAST_HOLEY_SMI_ELEMENTS - FAST_SMI_ELEMENTS; 83 84int ElementsKindToShiftSize(ElementsKind elements_kind); 85const char* ElementsKindToString(ElementsKind kind); 86void PrintElementsKind(FILE* out, ElementsKind kind); 87 88ElementsKind GetInitialFastElementsKind(); 89 90ElementsKind GetFastElementsKindFromSequenceIndex(int sequence_index); 91 92int GetSequenceIndexFromFastElementsKind(ElementsKind elements_kind); 93 94 95inline bool IsDictionaryElementsKind(ElementsKind kind) { 96 return kind == DICTIONARY_ELEMENTS; 97} 98 99 100inline bool IsExternalArrayElementsKind(ElementsKind kind) { 101 return kind >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND && 102 kind <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND; 103} 104 105 106inline bool IsFastElementsKind(ElementsKind kind) { 107 ASSERT(FIRST_FAST_ELEMENTS_KIND == 0); 108 return kind <= FAST_HOLEY_DOUBLE_ELEMENTS; 109} 110 111 112inline bool IsFastDoubleElementsKind(ElementsKind kind) { 113 return kind == FAST_DOUBLE_ELEMENTS || 114 kind == FAST_HOLEY_DOUBLE_ELEMENTS; 115} 116 117 118inline bool IsExternalFloatOrDoubleElementsKind(ElementsKind kind) { 119 return kind == EXTERNAL_DOUBLE_ELEMENTS || 120 kind == EXTERNAL_FLOAT_ELEMENTS; 121} 122 123 124inline bool IsDoubleOrFloatElementsKind(ElementsKind kind) { 125 return IsFastDoubleElementsKind(kind) || 126 IsExternalFloatOrDoubleElementsKind(kind); 127} 128 129 130inline 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 138inline bool IsFastSmiElementsKind(ElementsKind kind) { 139 return kind == FAST_SMI_ELEMENTS || 140 kind == FAST_HOLEY_SMI_ELEMENTS; 141} 142 143 144inline bool IsFastObjectElementsKind(ElementsKind kind) { 145 return kind == FAST_ELEMENTS || 146 kind == FAST_HOLEY_ELEMENTS; 147} 148 149 150inline 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 157inline bool IsHoleyElementsKind(ElementsKind kind) { 158 return IsFastHoleyElementsKind(kind) || 159 kind == DICTIONARY_ELEMENTS; 160} 161 162 163inline bool IsFastPackedElementsKind(ElementsKind kind) { 164 return kind == FAST_SMI_ELEMENTS || 165 kind == FAST_DOUBLE_ELEMENTS || 166 kind == FAST_ELEMENTS; 167} 168 169 170inline 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 184inline 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 198inline 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 206inline 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 214bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind, 215 ElementsKind to_kind); 216 217 218inline bool IsTransitionableFastElementsKind(ElementsKind from_kind) { 219 return IsFastElementsKind(from_kind) && 220 from_kind != TERMINAL_FAST_ELEMENTS_KIND; 221} 222 223 224ElementsKind GetNextMoreGeneralFastElementsKind(ElementsKind elements_kind, 225 bool allow_only_packed); 226 227 228inline 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