Line data Source code
1 : // Copyright 2012 the V8 project authors. All rights reserved.
2 : // Use of this source code is governed by a BSD-style license that can be
3 : // found in the LICENSE file.
4 :
5 : #ifndef V8_ELEMENTS_KIND_H_
6 : #define V8_ELEMENTS_KIND_H_
7 :
8 : #include "src/base/macros.h"
9 : #include "src/checks.h"
10 :
11 : namespace v8 {
12 : namespace internal {
13 :
14 : enum ElementsKind {
15 : // The "fast" kind for elements that only contain SMI values. Must be first
16 : // to make it possible to efficiently check maps for this kind.
17 : FAST_SMI_ELEMENTS,
18 : FAST_HOLEY_SMI_ELEMENTS,
19 :
20 : // The "fast" kind for tagged values. Must be second to make it possible to
21 : // efficiently check maps for this and the FAST_SMI_ONLY_ELEMENTS kind
22 : // together at once.
23 : FAST_ELEMENTS,
24 : FAST_HOLEY_ELEMENTS,
25 :
26 : // The "fast" kind for unwrapped, non-tagged double values.
27 : FAST_DOUBLE_ELEMENTS,
28 : FAST_HOLEY_DOUBLE_ELEMENTS,
29 :
30 : // The "slow" kind.
31 : DICTIONARY_ELEMENTS,
32 :
33 : // Elements kind of the "arguments" object (only in sloppy mode).
34 : FAST_SLOPPY_ARGUMENTS_ELEMENTS,
35 : SLOW_SLOPPY_ARGUMENTS_ELEMENTS,
36 :
37 : // For string wrapper objects ("new String('...')"), the string's characters
38 : // are overlaid onto a regular elements backing store.
39 : FAST_STRING_WRAPPER_ELEMENTS,
40 : SLOW_STRING_WRAPPER_ELEMENTS,
41 :
42 : // Fixed typed arrays.
43 : UINT8_ELEMENTS,
44 : INT8_ELEMENTS,
45 : UINT16_ELEMENTS,
46 : INT16_ELEMENTS,
47 : UINT32_ELEMENTS,
48 : INT32_ELEMENTS,
49 : FLOAT32_ELEMENTS,
50 : FLOAT64_ELEMENTS,
51 : UINT8_CLAMPED_ELEMENTS,
52 :
53 : // Sentinel ElementsKind for objects with no elements.
54 : NO_ELEMENTS,
55 :
56 : // Derived constants from ElementsKind.
57 : FIRST_ELEMENTS_KIND = FAST_SMI_ELEMENTS,
58 : LAST_ELEMENTS_KIND = UINT8_CLAMPED_ELEMENTS,
59 : FIRST_FAST_ELEMENTS_KIND = FAST_SMI_ELEMENTS,
60 : LAST_FAST_ELEMENTS_KIND = FAST_HOLEY_DOUBLE_ELEMENTS,
61 : FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = UINT8_ELEMENTS,
62 : LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND = UINT8_CLAMPED_ELEMENTS,
63 : TERMINAL_FAST_ELEMENTS_KIND = FAST_HOLEY_ELEMENTS
64 : };
65 :
66 : const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1;
67 : const int kFastElementsKindCount = LAST_FAST_ELEMENTS_KIND -
68 : FIRST_FAST_ELEMENTS_KIND + 1;
69 :
70 : // The number to add to a packed elements kind to reach a holey elements kind
71 : const int kFastElementsKindPackedToHoley =
72 : FAST_HOLEY_SMI_ELEMENTS - FAST_SMI_ELEMENTS;
73 :
74 : int ElementsKindToShiftSize(ElementsKind elements_kind);
75 : int GetDefaultHeaderSizeForElementsKind(ElementsKind elements_kind);
76 : const char* ElementsKindToString(ElementsKind kind);
77 :
78 : inline ElementsKind GetInitialFastElementsKind() { return FAST_SMI_ELEMENTS; }
79 :
80 : ElementsKind GetFastElementsKindFromSequenceIndex(int sequence_number);
81 : int GetSequenceIndexFromFastElementsKind(ElementsKind elements_kind);
82 :
83 : ElementsKind GetNextTransitionElementsKind(ElementsKind elements_kind);
84 :
85 : inline bool IsDictionaryElementsKind(ElementsKind kind) {
86 : return kind == DICTIONARY_ELEMENTS;
87 : }
88 :
89 : inline bool IsSloppyArgumentsElementsKind(ElementsKind kind) {
90 5631999 : return kind == FAST_SLOPPY_ARGUMENTS_ELEMENTS ||
91 1228826 : kind == SLOW_SLOPPY_ARGUMENTS_ELEMENTS;
92 : }
93 :
94 : inline bool IsStringWrapperElementsKind(ElementsKind kind) {
95 19777326 : return kind == FAST_STRING_WRAPPER_ELEMENTS ||
96 129458 : kind == SLOW_STRING_WRAPPER_ELEMENTS;
97 : }
98 :
99 3747 : inline bool IsFixedTypedArrayElementsKind(ElementsKind kind) {
100 41630687 : return kind >= FIRST_FIXED_TYPED_ARRAY_ELEMENTS_KIND &&
101 1974014 : kind <= LAST_FIXED_TYPED_ARRAY_ELEMENTS_KIND;
102 : }
103 :
104 :
105 : inline bool IsTerminalElementsKind(ElementsKind kind) {
106 277845 : return kind == TERMINAL_FAST_ELEMENTS_KIND ||
107 : IsFixedTypedArrayElementsKind(kind);
108 : }
109 :
110 :
111 5755 : inline bool IsFastElementsKind(ElementsKind kind) {
112 : STATIC_ASSERT(FIRST_FAST_ELEMENTS_KIND == 0);
113 143947266 : return kind <= FAST_HOLEY_DOUBLE_ELEMENTS;
114 : }
115 :
116 :
117 : inline bool IsTransitionElementsKind(ElementsKind kind) {
118 3323 : return IsFastElementsKind(kind) || IsFixedTypedArrayElementsKind(kind) ||
119 662535 : kind == FAST_SLOPPY_ARGUMENTS_ELEMENTS ||
120 3323 : kind == FAST_STRING_WRAPPER_ELEMENTS;
121 : }
122 :
123 :
124 : inline bool IsFastDoubleElementsKind(ElementsKind kind) {
125 42556681 : return kind == FAST_DOUBLE_ELEMENTS ||
126 4665806 : kind == FAST_HOLEY_DOUBLE_ELEMENTS;
127 : }
128 :
129 :
130 : inline bool IsFixedFloatElementsKind(ElementsKind kind) {
131 38646 : return kind == FLOAT32_ELEMENTS || kind == FLOAT64_ELEMENTS;
132 : }
133 :
134 :
135 : inline bool IsDoubleOrFloatElementsKind(ElementsKind kind) {
136 73521 : return IsFastDoubleElementsKind(kind) || IsFixedFloatElementsKind(kind);
137 : }
138 :
139 :
140 : inline bool IsFastSmiOrObjectElementsKind(ElementsKind kind) {
141 : return kind == FAST_SMI_ELEMENTS ||
142 : kind == FAST_HOLEY_SMI_ELEMENTS ||
143 : kind == FAST_ELEMENTS ||
144 2254997 : kind == FAST_HOLEY_ELEMENTS;
145 : }
146 :
147 :
148 : inline bool IsFastSmiElementsKind(ElementsKind kind) {
149 : return kind == FAST_SMI_ELEMENTS ||
150 1941341 : kind == FAST_HOLEY_SMI_ELEMENTS;
151 : }
152 :
153 36387 : inline bool IsFastNumberElementsKind(ElementsKind kind) {
154 41094 : return IsFastSmiElementsKind(kind) || IsFastDoubleElementsKind(kind);
155 : }
156 :
157 :
158 : inline bool IsFastObjectElementsKind(ElementsKind kind) {
159 6542159 : return kind == FAST_ELEMENTS ||
160 3213746 : kind == FAST_HOLEY_ELEMENTS;
161 : }
162 :
163 :
164 : inline bool IsFastHoleyElementsKind(ElementsKind kind) {
165 39441886 : return kind == FAST_HOLEY_SMI_ELEMENTS ||
166 39442178 : kind == FAST_HOLEY_DOUBLE_ELEMENTS ||
167 : kind == FAST_HOLEY_ELEMENTS;
168 : }
169 :
170 :
171 : inline bool IsHoleyElementsKind(ElementsKind kind) {
172 7718143 : return IsFastHoleyElementsKind(kind) ||
173 : kind == DICTIONARY_ELEMENTS;
174 : }
175 :
176 :
177 7004 : inline bool IsFastPackedElementsKind(ElementsKind kind) {
178 2499188 : return kind == FAST_SMI_ELEMENTS || kind == FAST_DOUBLE_ELEMENTS ||
179 7004 : kind == FAST_ELEMENTS;
180 : }
181 :
182 :
183 : inline ElementsKind GetPackedElementsKind(ElementsKind holey_kind) {
184 634610 : if (holey_kind == FAST_HOLEY_SMI_ELEMENTS) {
185 : return FAST_SMI_ELEMENTS;
186 : }
187 448551 : if (holey_kind == FAST_HOLEY_DOUBLE_ELEMENTS) {
188 : return FAST_DOUBLE_ELEMENTS;
189 : }
190 448388 : if (holey_kind == FAST_HOLEY_ELEMENTS) {
191 : return FAST_ELEMENTS;
192 : }
193 : return holey_kind;
194 : }
195 :
196 :
197 : inline ElementsKind GetHoleyElementsKind(ElementsKind packed_kind) {
198 13568539 : if (packed_kind == FAST_SMI_ELEMENTS) {
199 : return FAST_HOLEY_SMI_ELEMENTS;
200 : }
201 10781725 : if (packed_kind == FAST_DOUBLE_ELEMENTS) {
202 : return FAST_HOLEY_DOUBLE_ELEMENTS;
203 : }
204 10366851 : if (packed_kind == FAST_ELEMENTS) {
205 : return FAST_HOLEY_ELEMENTS;
206 : }
207 : return packed_kind;
208 : }
209 :
210 :
211 : inline ElementsKind FastSmiToObjectElementsKind(ElementsKind from_kind) {
212 : DCHECK(IsFastSmiElementsKind(from_kind));
213 : return (from_kind == FAST_SMI_ELEMENTS)
214 : ? FAST_ELEMENTS
215 : : FAST_HOLEY_ELEMENTS;
216 : }
217 :
218 :
219 : inline bool IsSimpleMapChangeTransition(ElementsKind from_kind,
220 : ElementsKind to_kind) {
221 4939 : return (GetHoleyElementsKind(from_kind) == to_kind) ||
222 3635 : (IsFastSmiElementsKind(from_kind) &&
223 : IsFastObjectElementsKind(to_kind));
224 : }
225 :
226 :
227 : bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind,
228 : ElementsKind to_kind);
229 :
230 :
231 : inline ElementsKind GetMoreGeneralElementsKind(ElementsKind from_kind,
232 : ElementsKind to_kind) {
233 17634796 : if (IsMoreGeneralElementsKindTransition(from_kind, to_kind)) {
234 : return to_kind;
235 : }
236 : return from_kind;
237 : }
238 :
239 :
240 : inline bool IsTransitionableFastElementsKind(ElementsKind from_kind) {
241 477825 : return IsFastElementsKind(from_kind) &&
242 : from_kind != TERMINAL_FAST_ELEMENTS_KIND;
243 : }
244 :
245 :
246 : } // namespace internal
247 : } // namespace v8
248 :
249 : #endif // V8_ELEMENTS_KIND_H_
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