![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to jsbit.h CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Synchronet] / sbbs / include / mozilla / js|
Return to jsbit.h CVS log | Up to [Synchronet] / sbbs / include / mozilla / js |
1.1 root 1: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2: /* ***** BEGIN LICENSE BLOCK *****
3: * Version: MPL 1.1/GPL 2.0/LGPL 2.1
4: *
5: * The contents of this file are subject to the Mozilla Public License Version
6: * 1.1 (the "License"); you may not use this file except in compliance with
7: * the License. You may obtain a copy of the License at
8: * http://www.mozilla.org/MPL/
9: *
10: * Software distributed under the License is distributed on an "AS IS" basis,
11: * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12: * for the specific language governing rights and limitations under the
13: * License.
14: *
15: * The Original Code is Mozilla Communicator client code, released
16: * March 31, 1998.
17: *
18: * The Initial Developer of the Original Code is
19: * Netscape Communications Corporation.
20: * Portions created by the Initial Developer are Copyright (C) 1998
21: * the Initial Developer. All Rights Reserved.
22: *
23: * Contributor(s):
24: *
25: * Alternatively, the contents of this file may be used under the terms of
26: * either of the GNU General Public License Version 2 or later (the "GPL"),
27: * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
28: * in which case the provisions of the GPL or the LGPL are applicable instead
29: * of those above. If you wish to allow use of your version of this file only
30: * under the terms of either the GPL or the LGPL, and not to allow others to
31: * use your version of this file under the terms of the MPL, indicate your
32: * decision by deleting the provisions above and replace them with the notice
33: * and other provisions required by the GPL or the LGPL. If you do not delete
34: * the provisions above, a recipient may use your version of this file under
35: * the terms of any one of the MPL, the GPL or the LGPL.
36: *
37: * ***** END LICENSE BLOCK ***** */
38:
39: #ifndef jsbit_h___
40: #define jsbit_h___
41:
42: #include "jstypes.h"
43: JS_BEGIN_EXTERN_C
44:
45: /*
46: ** A jsbitmap_t is a long integer that can be used for bitmaps
47: */
48: typedef JSUword jsbitmap_t; /* NSPR name, a la Unix system types */
49: typedef jsbitmap_t jsbitmap; /* JS-style scalar typedef name */
50:
51: #define JS_TEST_BIT(_map,_bit) \
52: ((_map)[(_bit)>>JS_BITS_PER_WORD_LOG2] & (1L << ((_bit) & (JS_BITS_PER_WORD-1))))
53: #define JS_SET_BIT(_map,_bit) \
54: ((_map)[(_bit)>>JS_BITS_PER_WORD_LOG2] |= (1L << ((_bit) & (JS_BITS_PER_WORD-1))))
55: #define JS_CLEAR_BIT(_map,_bit) \
56: ((_map)[(_bit)>>JS_BITS_PER_WORD_LOG2] &= ~(1L << ((_bit) & (JS_BITS_PER_WORD-1))))
57:
58: /*
59: ** Compute the log of the least power of 2 greater than or equal to n
60: */
61: extern JS_PUBLIC_API(JSIntn) JS_CeilingLog2(JSUint32 i);
62:
63: /*
64: ** Compute the log of the greatest power of 2 less than or equal to n
65: */
66: extern JS_PUBLIC_API(JSIntn) JS_FloorLog2(JSUint32 i);
67:
68: /*
69: ** Macro version of JS_CeilingLog2: Compute the log of the least power of
70: ** 2 greater than or equal to _n. The result is returned in _log2.
71: */
72: #define JS_CEILING_LOG2(_log2,_n) \
73: JS_BEGIN_MACRO \
74: JSUint32 j_ = (JSUint32)(_n); \
75: (_log2) = 0; \
76: if ((j_) & ((j_)-1)) \
77: (_log2) += 1; \
78: if ((j_) >> 16) \
79: (_log2) += 16, (j_) >>= 16; \
80: if ((j_) >> 8) \
81: (_log2) += 8, (j_) >>= 8; \
82: if ((j_) >> 4) \
83: (_log2) += 4, (j_) >>= 4; \
84: if ((j_) >> 2) \
85: (_log2) += 2, (j_) >>= 2; \
86: if ((j_) >> 1) \
87: (_log2) += 1; \
88: JS_END_MACRO
89:
90: /*
91: ** Macro version of JS_FloorLog2: Compute the log of the greatest power of
92: ** 2 less than or equal to _n. The result is returned in _log2.
93: **
94: ** This is equivalent to finding the highest set bit in the word.
95: */
96: #define JS_FLOOR_LOG2(_log2,_n) \
97: JS_BEGIN_MACRO \
98: JSUint32 j_ = (JSUint32)(_n); \
99: (_log2) = 0; \
100: if ((j_) >> 16) \
101: (_log2) += 16, (j_) >>= 16; \
102: if ((j_) >> 8) \
103: (_log2) += 8, (j_) >>= 8; \
104: if ((j_) >> 4) \
105: (_log2) += 4, (j_) >>= 4; \
106: if ((j_) >> 2) \
107: (_log2) += 2, (j_) >>= 2; \
108: if ((j_) >> 1) \
109: (_log2) += 1; \
110: JS_END_MACRO
111:
112: JS_END_EXTERN_C
113: #endif /* jsbit_h___ */
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.