1 /* bignum_copy.c - copy a bignum
2 Copyright (C) 1987, 1990, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
6 GAS is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GAS is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GAS; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 static char rcsid[] = "$FreeBSD$";
29 * Copy a bignum from in to out.
30 * If the output is shorter than the input, copy lower-order littlenums.
31 * Return 0 or the number of significant littlenums dropped.
32 * Assumes littlenum arrays are densely packed: no unused chars between
33 * the littlenums. Uses memcpy() to move littlenums, and wants to
34 * know length (in chars) of the input bignum.
39 bignum_copy(in, in_length, out, out_length)
40 register LITTLENUM_TYPE *in;
41 register int in_length; /* in sizeof(littlenum)s */
42 register LITTLENUM_TYPE *out;
43 register int out_length; /* in sizeof(littlenum)s */
45 int significant_littlenums_dropped;
47 if (out_length < in_length) {
48 LITTLENUM_TYPE *p; /* -> most significant (non-zero) input
51 memcpy((void *) out, (void *) in,
52 out_length << LITTLENUM_SHIFT);
53 for (p = in + in_length - 1; p >= in; --p) {
56 significant_littlenums_dropped = p - in - in_length + 1;
58 if (significant_littlenums_dropped < 0) {
59 significant_littlenums_dropped = 0;
62 memcpy((char *) out, (char *) in,
63 in_length << LITTLENUM_SHIFT);
65 if (out_length > in_length) {
66 memset((char *) (out + out_length),
67 '\0', (out_length - in_length) << LITTLENUM_SHIFT);
70 significant_littlenums_dropped = 0;
73 return(significant_littlenums_dropped);
76 /* end of bignum-copy.c */