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535751f3 | 1 | /* |
584449f4 KB |
2 | * Copyright (c) 1988 Regents of the University of California. |
3 | * All rights reserved. | |
535751f3 | 4 | * |
584449f4 | 5 | * Redistribution and use in source and binary forms are permitted |
b36fc510 KB |
6 | * provided that the above copyright notice and this paragraph are |
7 | * duplicated in all such forms and that any documentation, | |
8 | * advertising materials, and other materials related to such | |
9 | * distribution and use acknowledge that the software was developed | |
10 | * by the University of California, Berkeley. The name of the | |
11 | * University may not be used to endorse or promote products derived | |
12 | * from this software without specific prior written permission. | |
13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
535751f3 GM |
16 | */ |
17 | ||
584449f4 | 18 | #ifndef lint |
d43d1075 | 19 | static char sccsid[] = "@(#)genbsubs.c 4.1 (Berkeley) %G%"; |
584449f4 | 20 | #endif /* not lint */ |
535751f3 GM |
21 | |
22 | /* The output of bunequal is the offset of the byte which didn't match; | |
23 | * if all the bytes match, then we return n. | |
24 | * bunequal(s1, s2, n) */ | |
25 | ||
26 | int | |
27 | bunequal(s1, s2, n) | |
28 | register char *s1, *s2; | |
29 | register n; | |
30 | { | |
31 | register int i = 0; | |
32 | ||
33 | while (i++ < n) { | |
34 | if (*s1++ != *s2++) { | |
35 | break; | |
36 | } | |
37 | } | |
38 | return(i-1); | |
39 | } | |
40 | ||
41 | /* bskip(s1, n, b) : finds the first occurrence of any byte != 'b' in the 'n' | |
42 | * bytes beginning at 's1'. | |
43 | */ | |
44 | ||
45 | int | |
46 | bskip(s1, n, b) | |
47 | register char *s1; | |
48 | register int n; | |
49 | register int b; | |
50 | { | |
51 | register int i = 0; | |
52 | ||
53 | while (i++ < n) { | |
54 | if (*s1++ != b) { | |
55 | break; | |
56 | } | |
57 | } | |
58 | return(i-1); | |
59 | } | |
eb8f58d6 GM |
60 | |
61 | /* | |
a3e38099 | 62 | * memNSchr(const void *s, int c, size_t n, int and) |
eb8f58d6 GM |
63 | * |
64 | * Like memchr, but the comparison is '((*s)&and) == c', | |
65 | * and we increment our way through s by "stride" ('s += stride'). | |
66 | * | |
67 | * We optimize for the most used strides of +1 and -1. | |
68 | */ | |
69 | ||
70 | unsigned char * | |
71 | memNSchr(s, c, n, and, stride) | |
72 | char *s; | |
73 | int c; | |
74 | unsigned int n; | |
75 | int and; | |
76 | int stride; | |
77 | { | |
78 | register unsigned char _c, *_s, _and; | |
79 | ||
80 | _and = and; | |
81 | _c = (c&_and); | |
82 | _s = (unsigned char *)s; | |
83 | switch (stride) { | |
84 | case 1: | |
85 | while (n--) { | |
86 | if (((*_s)&_and) == _c) { | |
87 | return _s; | |
88 | } | |
89 | _s++; | |
90 | } | |
91 | break; | |
92 | case -1: | |
93 | while (n--) { | |
94 | if (((*_s)&_and) == _c) { | |
95 | return _s; | |
96 | } | |
97 | _s--; | |
98 | } | |
99 | break; | |
100 | default: | |
101 | while (n--) { | |
102 | if (((*_s)&_and) == _c) { | |
103 | return _s; | |
104 | } | |
105 | _s += stride; | |
106 | } | |
107 | } | |
108 | return 0; | |
109 | } |