NetBSD/gnu/usr.bin/gas/bignum-copy.c

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/* bignum_copy.c - copy a bignum
Copyright (C) 1987, 1990, 1991, 1992 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#ifndef lint
static char rcsid[] = "$Id: bignum-copy.c,v 1.3 1993/10/02 20:57:18 pk Exp $";
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#endif
#include "as.h"
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/*
* bignum_copy ()
*
* Copy a bignum from in to out.
* If the output is shorter than the input, copy lower-order littlenums.
* Return 0 or the number of significant littlenums dropped.
* Assumes littlenum arrays are densely packed: no unused chars between
* the littlenums. Uses memcpy() to move littlenums, and wants to
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* know length (in chars) of the input bignum.
*/
/* void */
int
bignum_copy(in, in_length, out, out_length)
register LITTLENUM_TYPE *in;
register int in_length; /* in sizeof(littlenum)s */
register LITTLENUM_TYPE *out;
register int out_length; /* in sizeof(littlenum)s */
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{
int significant_littlenums_dropped;
if (out_length < in_length) {
LITTLENUM_TYPE *p; /* -> most significant (non-zero) input
littlenum. */
memcpy((void *) out, (void *) in,
out_length << LITTLENUM_SHIFT);
for (p = in + in_length - 1; p >= in; --p) {
if (* p) break;
}
significant_littlenums_dropped = p - in - in_length + 1;
if (significant_littlenums_dropped < 0) {
significant_littlenums_dropped = 0;
}
} else {
memcpy((char *) out, (char *) in,
in_length << LITTLENUM_SHIFT);
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if (out_length > in_length) {
memset((char *) (out + out_length),
'\0', (out_length - in_length) << LITTLENUM_SHIFT);
}
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significant_littlenums_dropped = 0;
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}
return(significant_littlenums_dropped);
} /* bignum_copy() */
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/* end of bignum-copy.c */