1 /* bignum_copy.c - copy a bignum
2 Copyright (C) 1987, 1990, 1991 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 1, 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. */
20 /* static const char rcsid[] = "$Id$"; */
25 #define bzero(s,n) memset(s,0,n)
26 #define bcopy(from,to,n) memcpy(to,from,n)
32 * Copy a bignum from in to out.
33 * If the output is shorter than the input, copy lower-order littlenums.
34 * Return 0 or the number of significant littlenums dropped.
35 * Assumes littlenum arrays are densely packed: no unused chars between
36 * the littlenums. Uses bcopy() to move littlenums, and wants to
37 * know length (in chars) of the input bignum.
42 bignum_copy (in
, in_length
, out
, out_length
)
43 register LITTLENUM_TYPE
* in
;
44 register int in_length
; /* in sizeof(littlenum)s */
45 register LITTLENUM_TYPE
* out
;
46 register int out_length
; /* in sizeof(littlenum)s */
48 register int significant_littlenums_dropped
;
50 if (out_length
< in_length
)
52 register LITTLENUM_TYPE
* p
; /* -> most significant (non-zero) input littlenum. */
54 bcopy ((char *)in
, (char *)out
, out_length
<< LITTLENUM_SHIFT
);
55 for (p
= in
+ in_length
- 1; p
>= in
; -- p
)
59 significant_littlenums_dropped
= p
- in
- in_length
+ 1;
60 if (significant_littlenums_dropped
< 0)
62 significant_littlenums_dropped
= 0;
67 bcopy ((char *)in
, (char *)out
, in_length
<< LITTLENUM_SHIFT
);
68 if (out_length
> in_length
)
70 bzero ((char *)(out
+ out_length
), (out_length
- in_length
) << LITTLENUM_SHIFT
);
72 significant_littlenums_dropped
= 0;
74 return (significant_littlenums_dropped
);
77 /* end: bignum_copy.c */