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