stk/Mp/gmp-1.3.2/mpz_mmod.c

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1996-09-27 06:29:02 -04:00
/* mpz_mmod -- Mathematical MODulo, i.e. with the remainder
non-negative.
Copyright (C) 1991, 1992 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"
void
#ifdef __STDC__
mpz_mmod (MP_INT *rem,
const MP_INT *dividend, const MP_INT *divisor)
#else
mpz_mmod (rem, dividend, divisor)
MP_INT *rem;
const MP_INT *dividend;
const MP_INT *divisor;
#endif
{
if ((dividend->size ^ divisor->size) >= 0)
{
/* When the dividend and the divisor has same sign, this function
gives same result as mpz_mod. */
mpz_mod (rem, dividend, divisor);
}
else
{
MP_INT temp_divisor; /* N.B.: lives until function returns! */
/* We need the original value of the divisor after the remainder has
been preliminary calculated. We have to copy it to temporary
space if it's the same variable as REM. */
if (rem == divisor)
{
MPZ_TMP_INIT (&temp_divisor, ABS (divisor->size));
mpz_set (&temp_divisor, divisor);
divisor = &temp_divisor;
}
mpz_mod (rem, dividend, divisor);
if (rem->size != 0)
mpz_add (rem, rem, divisor);
}
}