Annotation of prex/usr/lib/libc/string/bcopy.c, Revision 1.1.1.1
1.1 nbrk 1: /*-
2: * Copyright (c) 1990, 1993
3: * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: */
32:
33: #include <sys/cdefs.h>
34: #include <string.h>
35:
36: /*
37: * Copy a block of memory, handling overlap.
38: * This is the routine that actually implements
39: * (the portable versions of) bcopy, memcpy, and memmove.
40: */
41: #ifdef MEMCOPY
42: void *
43: memcpy(dst0, src0, length)
44: #else
45: #ifdef MEMMOVE
46: void *
47: memmove(dst0, src0, length)
48: #else
49: void
50: bcopy(src0, dst0, length)
51: #endif
52: #endif
53: void *dst0;
54: const void *src0;
55: size_t length;
56: {
57: char *dst = dst0;
58: const char *src = src0;
59:
60: if (length == 0 || dst == src) /* nothing to do */
61: goto done;
62:
63: if (((unsigned long)dst < (unsigned long)src) &&
64: ((unsigned long)dst < (unsigned long)src + length)) {
65: /* Copy backwards. */
66: src += length;
67: dst += length;
68: while (length--) {
69: *--dst = *--src;
70: }
71: } else {
72: while (length--) {
73: *dst++ = *src++;
74: }
75: }
76: done:
77: #if defined(MEMCOPY) || defined(MEMMOVE)
78: return (dst0);
79: #else
80: return;
81: #endif
82: }
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