122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
/* mpz_add -- Add two integers.
|
|
|
|
Copyright (C) 1991 Free Software Foundation, Inc.
|
|
|
|
This file is part of the GNU MP Library.
|
|
|
|
The GNU MP Library 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.
|
|
|
|
The GNU MP Library 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 the GNU MP Library; see the file COPYING. If not, write to
|
|
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
|
|
|
|
#include "gmp.h"
|
|
#include "gmp-impl.h"
|
|
|
|
#ifndef BERKELEY_MP
|
|
void
|
|
#ifdef __STDC__
|
|
mpz_add (MP_INT *sum, const MP_INT *u, const MP_INT *v)
|
|
#else
|
|
mpz_add (sum, u, v)
|
|
MP_INT *sum;
|
|
const MP_INT *u;
|
|
const MP_INT *v;
|
|
#endif
|
|
#else /* BERKELEY_MP */
|
|
void
|
|
#ifdef __STDC__
|
|
madd (const MP_INT *u, const MP_INT *v, MP_INT *sum)
|
|
#else
|
|
madd (u, v, sum)
|
|
const MP_INT *u;
|
|
const MP_INT *v;
|
|
MP_INT *sum;
|
|
#endif
|
|
#endif /* BERKELEY_MP */
|
|
{
|
|
mp_srcptr up, vp;
|
|
mp_ptr sump;
|
|
mp_size usize, vsize, sumsize;
|
|
mp_size abs_usize;
|
|
mp_size abs_vsize;
|
|
|
|
usize = u->size;
|
|
vsize = v->size;
|
|
abs_usize = ABS (usize);
|
|
abs_vsize = ABS (vsize);
|
|
|
|
if (abs_usize < abs_vsize)
|
|
{
|
|
/* Swap U and V. */
|
|
{const MP_INT *t = u; u = v; v = t;}
|
|
{mp_size t = usize; usize = vsize; vsize = t;}
|
|
{mp_size t = abs_usize; abs_usize = abs_vsize; abs_vsize = t;}
|
|
}
|
|
|
|
/* True: abs(USIZE) >= abs(VSIZE) */
|
|
|
|
/* If not space for sum (and possible carry), increase space. */
|
|
sumsize = abs_usize + 1;
|
|
if (sum->alloc < sumsize)
|
|
_mpz_realloc (sum, sumsize);
|
|
|
|
/* These must be after realloc (u or v may be the same as sum). */
|
|
up = u->d;
|
|
vp = v->d;
|
|
sump = sum->d;
|
|
|
|
if (usize >= 0)
|
|
{
|
|
if (vsize >= 0)
|
|
{
|
|
sumsize = mpn_add (sump, up, abs_usize, vp, abs_vsize);
|
|
if (sumsize != 0)
|
|
sump[abs_usize] = 1;
|
|
sumsize = sumsize + abs_usize;
|
|
}
|
|
else
|
|
{
|
|
/* The signs are different. Need exact comparision to determine
|
|
which operand to subtract from which. */
|
|
if (abs_usize == abs_vsize && mpn_cmp (up, vp, abs_usize) < 0)
|
|
sumsize = -(abs_usize
|
|
+ mpn_sub (sump, vp, abs_usize, up, abs_usize));
|
|
else
|
|
sumsize = (abs_usize
|
|
+ mpn_sub (sump, up, abs_usize, vp, abs_vsize));
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (vsize >= 0)
|
|
{
|
|
/* The signs are different. Need exact comparision to determine
|
|
which operand to subtract from which. */
|
|
if (abs_usize == abs_vsize && mpn_cmp (up, vp, abs_usize) < 0)
|
|
sumsize = (abs_usize
|
|
+ mpn_sub (sump, vp, abs_usize, up, abs_usize));
|
|
else
|
|
sumsize = -(abs_usize
|
|
+ mpn_sub (sump, up, abs_usize, vp, abs_vsize));
|
|
}
|
|
else
|
|
{
|
|
sumsize = mpn_add (sump, up, abs_usize, vp, abs_vsize);
|
|
if (sumsize != 0)
|
|
sump[abs_usize] = 1;
|
|
sumsize = -(sumsize + abs_usize);
|
|
}
|
|
}
|
|
|
|
sum->size = sumsize;
|
|
}
|