freebsd-dev/gnu/lib/libgmp/mpq_set_si.c
Mark Murray ae82e96f8c GNU MP (Multiprecision) library. This is needed by secure RPC (being
done by Bill Paul) and various other BSD programs.
Obtained from:FSF
1995-11-12 14:40:41 +00:00

77 lines
1.8 KiB
C

/* mpq_set_si(dest,ulong_num,ulong_den) -- Set DEST to the retional number
ULONG_NUM/ULONG_DEN.
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"
static unsigned long int
gcd (x, y)
unsigned long int x, y;
{
for (;;)
{
x = x % y;
if (x == 0)
return y;
y = y % x;
if (y == 0)
return x;
}
}
void
#ifdef __STDC__
mpq_set_si (MP_RAT *dest, signed long int num, unsigned long int den)
#else
mpq_set_si (dest, num, den)
MP_RAT *dest;
signed long int num;
unsigned long int den;
#endif
{
unsigned long int g;
unsigned long int abs_num;
abs_num = ABS (num);
if (num == 0)
{
/* Canonicalize 0/d to 0/1. */
den = 1;
dest->num.size = 0;
}
else
{
/* Remove any common factor in NUM and DEN. */
/* Pass DEN as the second argument to gcd, in order to make the
gcd function divide by zero if DEN is zero. */
g = gcd (abs_num, den);
abs_num /= g;
den /= g;
dest->num.d[0] = abs_num;
dest->num.size = num > 0 ? 1 : -1;
}
dest->den.d[0] = den;
dest->den.size = 1;
}