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author | deraadt <> | 1995-10-18 08:42:23 +0000 |
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committer | deraadt <> | 1995-10-18 08:42:23 +0000 |
commit | 0527d29da443886d92e9a418180c5b25a5f8d270 (patch) | |
tree | 86b3a64928451a669cefa27900e5884036b4e349 /src/lib/libc/string/bcopy.c | |
download | openbsd-0527d29da443886d92e9a418180c5b25a5f8d270.tar.gz openbsd-0527d29da443886d92e9a418180c5b25a5f8d270.tar.bz2 openbsd-0527d29da443886d92e9a418180c5b25a5f8d270.zip |
initial import of NetBSD tree
Diffstat (limited to 'src/lib/libc/string/bcopy.c')
-rw-r--r-- | src/lib/libc/string/bcopy.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/src/lib/libc/string/bcopy.c b/src/lib/libc/string/bcopy.c new file mode 100644 index 0000000000..92feed66ea --- /dev/null +++ b/src/lib/libc/string/bcopy.c | |||
@@ -0,0 +1,139 @@ | |||
1 | /*- | ||
2 | * Copyright (c) 1990 The Regents of the University of California. | ||
3 | * All rights reserved. | ||
4 | * | ||
5 | * This code is derived from software contributed to Berkeley by | ||
6 | * Chris Torek. | ||
7 | * | ||
8 | * Redistribution and use in source and binary forms, with or without | ||
9 | * modification, are permitted provided that the following conditions | ||
10 | * are met: | ||
11 | * 1. Redistributions of source code must retain the above copyright | ||
12 | * notice, this list of conditions and the following disclaimer. | ||
13 | * 2. Redistributions in binary form must reproduce the above copyright | ||
14 | * notice, this list of conditions and the following disclaimer in the | ||
15 | * documentation and/or other materials provided with the distribution. | ||
16 | * 3. All advertising materials mentioning features or use of this software | ||
17 | * must display the following acknowledgement: | ||
18 | * This product includes software developed by the University of | ||
19 | * California, Berkeley and its contributors. | ||
20 | * 4. Neither the name of the University nor the names of its contributors | ||
21 | * may be used to endorse or promote products derived from this software | ||
22 | * without specific prior written permission. | ||
23 | * | ||
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | ||
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | ||
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
34 | * SUCH DAMAGE. | ||
35 | */ | ||
36 | |||
37 | #if defined(LIBC_SCCS) && !defined(lint) | ||
38 | /*static char *sccsid = "from: @(#)bcopy.c 5.11 (Berkeley) 6/21/91";*/ | ||
39 | static char *rcsid = "$Id: bcopy.c,v 1.1.1.1 1995/10/18 08:42:20 deraadt Exp $"; | ||
40 | #endif /* LIBC_SCCS and not lint */ | ||
41 | |||
42 | #include <string.h> | ||
43 | |||
44 | /* | ||
45 | * sizeof(word) MUST BE A POWER OF TWO | ||
46 | * SO THAT wmask BELOW IS ALL ONES | ||
47 | */ | ||
48 | typedef long word; /* "word" used for optimal copy speed */ | ||
49 | |||
50 | #define wsize sizeof(word) | ||
51 | #define wmask (wsize - 1) | ||
52 | |||
53 | /* | ||
54 | * Copy a block of memory, handling overlap. | ||
55 | * This is the routine that actually implements | ||
56 | * (the portable versions of) bcopy, memcpy, and memmove. | ||
57 | */ | ||
58 | #ifdef MEMCOPY | ||
59 | void * | ||
60 | memcpy(dst0, src0, length) | ||
61 | #else | ||
62 | #ifdef MEMMOVE | ||
63 | void * | ||
64 | memmove(dst0, src0, length) | ||
65 | #else | ||
66 | void | ||
67 | bcopy(src0, dst0, length) | ||
68 | #endif | ||
69 | #endif | ||
70 | void *dst0; | ||
71 | const void *src0; | ||
72 | register size_t length; | ||
73 | { | ||
74 | register char *dst = dst0; | ||
75 | register const char *src = src0; | ||
76 | register size_t t; | ||
77 | |||
78 | if (length == 0 || dst == src) /* nothing to do */ | ||
79 | goto done; | ||
80 | |||
81 | /* | ||
82 | * Macros: loop-t-times; and loop-t-times, t>0 | ||
83 | */ | ||
84 | #define TLOOP(s) if (t) TLOOP1(s) | ||
85 | #define TLOOP1(s) do { s; } while (--t) | ||
86 | |||
87 | if ((unsigned long)dst < (unsigned long)src) { | ||
88 | /* | ||
89 | * Copy forward. | ||
90 | */ | ||
91 | t = (long)src; /* only need low bits */ | ||
92 | if ((t | (long)dst) & wmask) { | ||
93 | /* | ||
94 | * Try to align operands. This cannot be done | ||
95 | * unless the low bits match. | ||
96 | */ | ||
97 | if ((t ^ (long)dst) & wmask || length < wsize) | ||
98 | t = length; | ||
99 | else | ||
100 | t = wsize - (t & wmask); | ||
101 | length -= t; | ||
102 | TLOOP1(*dst++ = *src++); | ||
103 | } | ||
104 | /* | ||
105 | * Copy whole words, then mop up any trailing bytes. | ||
106 | */ | ||
107 | t = length / wsize; | ||
108 | TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize); | ||
109 | t = length & wmask; | ||
110 | TLOOP(*dst++ = *src++); | ||
111 | } else { | ||
112 | /* | ||
113 | * Copy backwards. Otherwise essentially the same. | ||
114 | * Alignment works as before, except that it takes | ||
115 | * (t&wmask) bytes to align, not wsize-(t&wmask). | ||
116 | */ | ||
117 | src += length; | ||
118 | dst += length; | ||
119 | t = (long)src; | ||
120 | if ((t | (long)dst) & wmask) { | ||
121 | if ((t ^ (long)dst) & wmask || length <= wsize) | ||
122 | t = length; | ||
123 | else | ||
124 | t &= wmask; | ||
125 | length -= t; | ||
126 | TLOOP1(*--dst = *--src); | ||
127 | } | ||
128 | t = length / wsize; | ||
129 | TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src); | ||
130 | t = length & wmask; | ||
131 | TLOOP(*--dst = *--src); | ||
132 | } | ||
133 | done: | ||
134 | #if defined(MEMCOPY) || defined(MEMMOVE) | ||
135 | return (dst0); | ||
136 | #else | ||
137 | return; | ||
138 | #endif | ||
139 | } | ||