1 : /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 : * vim: set ts=4 sw=4 et tw=99 ft=cpp:
3 : *
4 : * ***** BEGIN LICENSE BLOCK *****
5 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6 : *
7 : * The contents of this file are subject to the Mozilla Public License Version
8 : * 1.1 (the "License"); you may not use this file except in compliance with
9 : * the License. You may obtain a copy of the License at
10 : * http://www.mozilla.org/MPL/
11 : *
12 : * Software distributed under the License is distributed on an "AS IS" basis,
13 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14 : * for the specific language governing rights and limitations under the
15 : * License.
16 : *
17 : * The Original Code is SpiderMonkey JavaScript engine.
18 : *
19 : * The Initial Developer of the Original Code is
20 : * Mozilla Corporation.
21 : * Portions created by the Initial Developer are Copyright (C) 2011
22 : * the Initial Developer. All Rights Reserved.
23 : *
24 : * Contributor(s):
25 : * Terrence Cole <terrence@mozilla.com>
26 : *
27 : * Alternatively, the contents of this file may be used under the terms of
28 : * either the GNU General Public License Version 2 or later (the "GPL"), or
29 : * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
30 : * in which case the provisions of the GPL or the LGPL are applicable instead
31 : * of those above. If you wish to allow use of your version of this file only
32 : * under the terms of either the GPL or the LGPL, and not to allow others to
33 : * use your version of this file under the terms of the MPL, indicate your
34 : * decision by deleting the provisions above and replace them with the notice
35 : * and other provisions required by the GPL or the LGPL. If you do not delete
36 : * the provisions above, a recipient may use your version of this file under
37 : * the terms of any one of the MPL, the GPL or the LGPL.
38 : *
39 : * ***** END LICENSE BLOCK ***** */
40 :
41 : #ifndef BitArray_h__
42 : #define BitArray_h__
43 :
44 : #include "jstypes.h"
45 :
46 : #include "js/TemplateLib.h"
47 :
48 : namespace js {
49 :
50 : template <size_t nbits>
51 : class BitArray {
52 : private:
53 : uintptr_t map[nbits / JS_BITS_PER_WORD + (nbits % JS_BITS_PER_WORD == 0 ? 0 : 1)];
54 :
55 : public:
56 43620 : void clear(bool value) {
57 43620 : if (value)
58 0 : memset(map, 0xFF, sizeof(map));
59 : else
60 43620 : memset(map, 0, sizeof(map));
61 43620 : }
62 :
63 11624237 : inline bool get(size_t offset) const {
64 : uintptr_t index, mask;
65 11624237 : getMarkWordAndMask(offset, &index, &mask);
66 11624237 : return map[index] & mask;
67 : }
68 :
69 4140 : inline void set(size_t offset) {
70 : uintptr_t index, mask;
71 4140 : getMarkWordAndMask(offset, &index, &mask);
72 4140 : map[index] |= mask;
73 4140 : }
74 :
75 0 : inline void unset(size_t offset) {
76 : uintptr_t index, mask;
77 0 : getMarkWordAndMask(offset, &index, &mask);
78 0 : map[index] &= ~mask;
79 0 : }
80 :
81 : private:
82 11628377 : inline void getMarkWordAndMask(size_t offset,
83 : uintptr_t *indexp, uintptr_t *maskp) const {
84 11628377 : *indexp = offset >> tl::FloorLog2<JS_BITS_PER_WORD>::result;
85 11628377 : *maskp = uintptr_t(1) << (offset & (JS_BITS_PER_WORD - 1));
86 11628377 : }
87 : };
88 :
89 : } /* namespace js */
90 :
91 : #endif
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