xref: /dflybsd-src/contrib/gmp/mpq/cmp_si.c (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)

/* _mpq_cmp_si -- compare mpq and long/ulong fraction.

Copyright 2001 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 Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, 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 Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */

#include "gmp.h"
#include "gmp-impl.h"


/* Something like mpq_cmpabs_ui would be more useful for the neg/neg case,
   and perhaps a version accepting a parameter to reverse the test, to make
   it a tail call here.  */

int
_mpq_cmp_si (mpq_srcptr q, long n, unsigned long d)
{
  /* need canonical sign to get right result */
  ASSERT (q->_mp_den._mp_size > 0);

  if (q->_mp_num._mp_size >= 0)
    {
      if (n >= 0)
        return _mpq_cmp_ui (q, n, d);            /* >=0 cmp >=0 */
      else
        return 1;                                /* >=0 cmp <0 */
    }
  else
    {
      if (n >= 0)
        return -1;                               /* <0 cmp >=0 */
      else
        {
          mpq_t  qabs;
          qabs->_mp_num._mp_size = ABS (q->_mp_num._mp_size);
          qabs->_mp_num._mp_d    = q->_mp_num._mp_d;
          qabs->_mp_den._mp_size = q->_mp_den._mp_size;
          qabs->_mp_den._mp_d    = q->_mp_den._mp_d;

          return - _mpq_cmp_ui (qabs, -n, d);    /* <0 cmp <0 */
        }
    }
}