93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
|
/* mpq_div -- divide two rational numbers.
|
||
|
|
|
||
|
|
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"
|
||
|
|
|
||
|
|
void
|
||
|
|
#ifdef __STDC__
|
||
|
|
mpq_div (MP_RAT *quot, const MP_RAT *dividend, const MP_RAT *divisor)
|
||
|
|
#else
|
||
|
|
mpq_div (quot, dividend, divisor)
|
||
|
|
MP_RAT *quot;
|
||
|
|
const MP_RAT *dividend;
|
||
|
|
const MP_RAT *divisor;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
MP_INT gcd1, gcd2;
|
||
|
|
MP_INT tmp1, tmp2;
|
||
|
|
MP_INT numtmp;
|
||
|
|
|
||
|
|
mpz_init (&gcd1);
|
||
|
|
mpz_init (&gcd2);
|
||
|
|
mpz_init (&tmp1);
|
||
|
|
mpz_init (&tmp2);
|
||
|
|
mpz_init (&numtmp);
|
||
|
|
|
||
|
|
/* QUOT might be identical to either operand, so don't store the
|
||
|
|
result there until we are finished with the input operands. We
|
||
|
|
dare to overwrite the numerator of QUOT when we are finished
|
||
|
|
with the numerators of DIVIDEND and DIVISOR. */
|
||
|
|
|
||
|
|
mpz_gcd (&gcd1, &(dividend->num), &(divisor->num));
|
||
|
|
mpz_gcd (&gcd2, &(divisor->den), &(dividend->den));
|
||
|
|
|
||
|
|
if (gcd1.size > 1 || gcd1.d[0] != 1)
|
||
|
|
mpz_div (&tmp1, &(dividend->num), &gcd1);
|
||
|
|
else
|
||
|
|
mpz_set (&tmp1, &(dividend->num));
|
||
|
|
|
||
|
|
if (gcd2.size > 1 || gcd2.d[0] != 1)
|
||
|
|
mpz_div (&tmp2, &(divisor->den), &gcd2);
|
||
|
|
else
|
||
|
|
mpz_set (&tmp2, &(divisor->den));
|
||
|
|
|
||
|
|
mpz_mul (&numtmp, &tmp1, &tmp2);
|
||
|
|
|
||
|
|
if (gcd1.size > 1 || gcd1.d[0] != 1)
|
||
|
|
mpz_div (&tmp1, &(divisor->num), &gcd1);
|
||
|
|
else
|
||
|
|
mpz_set (&tmp1, &(divisor->num));
|
||
|
|
|
||
|
|
if (gcd2.size > 1 || gcd2.d[0] != 1)
|
||
|
|
mpz_div (&tmp2, &(dividend->den), &gcd2);
|
||
|
|
else
|
||
|
|
mpz_set (&tmp2, &(dividend->den));
|
||
|
|
|
||
|
|
mpz_mul (&(quot->den), &tmp1, &tmp2);
|
||
|
|
|
||
|
|
/* We needed to go via NUMTMP to take care of QUOT being the same
|
||
|
|
as either input operands. Now move NUMTMP to QUOT->NUM. */
|
||
|
|
mpz_set (&(quot->num), &numtmp);
|
||
|
|
|
||
|
|
/* Keep the denominator positive. */
|
||
|
|
if (quot->den.size < 0)
|
||
|
|
{
|
||
|
|
quot->den.size = -quot->den.size;
|
||
|
|
quot->num.size = -quot->num.size;
|
||
|
|
}
|
||
|
|
|
||
|
|
mpz_clear (&numtmp);
|
||
|
|
mpz_clear (&tmp2);
|
||
|
|
mpz_clear (&tmp1);
|
||
|
|
mpz_clear (&gcd2);
|
||
|
|
mpz_clear (&gcd1);
|
||
|
|
}
|