7622428423ba9e5ef325aede20958c89cf1a5b9d
[gcc.git] / libchill / memmove.c
1 /* Implement string-related runtime actions for CHILL.
2 Copyright (C) 1992,1993 Free Software Foundation, Inc.
3 Author: Bill Cox
4
5 This file is part of GNU CC.
6
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
11
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
20
21 #define MIN(a, b) ((a) < (b) ? (a) : (b))
22
23
24 /*
25 * function memmove
26 *
27 * parameters:
28 * S1 - pointer to destination string
29 * S2 - pointer to source string
30 * LEN - length of string
31 *
32 * returns:
33 * pointer to destination string
34 *
35 * exceptions:
36 * none
37 *
38 * abstract:
39 * copies a string safely, where the source and dest areas may overlap.
40 *
41 */
42
43 void *
44 memmove (s1, s2, n)
45 void *s1;
46 const void *s2;
47 int n;
48 {
49 char *sc1 = s1;
50 const char *sc2 = s2;
51
52 if (sc2 < sc1 && (sc1 < sc2 + n))
53 for (sc1 += n, sc2 += n; 0 < n; --n)
54 *--sc1 = *--sc2;
55 else
56 #if 0
57 for (; 0 < n; --n)
58 *sc1++ = *sc2++;
59 #else
60 memcpy (sc1, sc2, n);
61 #endif
62 return s1;
63 }