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 //
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7 // notice, this list of conditions and the following disclaimer.
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9 // copyright notice, this list of conditions and the following
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15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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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
IsDictionaryElementsKind(ElementsKind kind)95 inline bool IsDictionaryElementsKind(ElementsKind kind) {
96 return kind == DICTIONARY_ELEMENTS;
97 }
98
99
IsExternalArrayElementsKind(ElementsKind kind)100 inline bool IsExternalArrayElementsKind(ElementsKind kind) {
101 return kind >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND &&
102 kind <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND;
103 }
104
105
IsFastElementsKind(ElementsKind kind)106 inline bool IsFastElementsKind(ElementsKind kind) {
107 ASSERT(FIRST_FAST_ELEMENTS_KIND == 0);
108 return kind <= FAST_HOLEY_DOUBLE_ELEMENTS;
109 }
110
111
IsFastDoubleElementsKind(ElementsKind kind)112 inline bool IsFastDoubleElementsKind(ElementsKind kind) {
113 return kind == FAST_DOUBLE_ELEMENTS ||
114 kind == FAST_HOLEY_DOUBLE_ELEMENTS;
115 }
116
117
IsExternalFloatOrDoubleElementsKind(ElementsKind kind)118 inline bool IsExternalFloatOrDoubleElementsKind(ElementsKind kind) {
119 return kind == EXTERNAL_DOUBLE_ELEMENTS ||
120 kind == EXTERNAL_FLOAT_ELEMENTS;
121 }
122
123
IsDoubleOrFloatElementsKind(ElementsKind kind)124 inline bool IsDoubleOrFloatElementsKind(ElementsKind kind) {
125 return IsFastDoubleElementsKind(kind) ||
126 IsExternalFloatOrDoubleElementsKind(kind);
127 }
128
129
IsFastSmiOrObjectElementsKind(ElementsKind kind)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
IsFastSmiElementsKind(ElementsKind kind)138 inline bool IsFastSmiElementsKind(ElementsKind kind) {
139 return kind == FAST_SMI_ELEMENTS ||
140 kind == FAST_HOLEY_SMI_ELEMENTS;
141 }
142
143
IsFastObjectElementsKind(ElementsKind kind)144 inline bool IsFastObjectElementsKind(ElementsKind kind) {
145 return kind == FAST_ELEMENTS ||
146 kind == FAST_HOLEY_ELEMENTS;
147 }
148
149
IsFastHoleyElementsKind(ElementsKind kind)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
IsHoleyElementsKind(ElementsKind kind)157 inline bool IsHoleyElementsKind(ElementsKind kind) {
158 return IsFastHoleyElementsKind(kind) ||
159 kind == DICTIONARY_ELEMENTS;
160 }
161
162
IsFastPackedElementsKind(ElementsKind kind)163 inline bool IsFastPackedElementsKind(ElementsKind kind) {
164 return kind == FAST_SMI_ELEMENTS ||
165 kind == FAST_DOUBLE_ELEMENTS ||
166 kind == FAST_ELEMENTS;
167 }
168
169
GetPackedElementsKind(ElementsKind holey_kind)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
GetHoleyElementsKind(ElementsKind packed_kind)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
FastSmiToObjectElementsKind(ElementsKind from_kind)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
IsSimpleMapChangeTransition(ElementsKind from_kind,ElementsKind to_kind)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
IsTransitionableFastElementsKind(ElementsKind from_kind)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
CanTransitionToMoreGeneralFastElementsKind(ElementsKind elements_kind,bool allow_only_packed)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