-/* mpq_inv(dest,src) -- invert a rational number, i.e. set DEST to SRC
- with the numerator and denominator swapped.
-
-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_inv (MP_RAT *dest, const MP_RAT *src)
-#else
-mpq_inv (dest, src)
- MP_RAT *dest;
- const MP_RAT *src;
-#endif
-{
- mp_size num_size = src->num.size;
- mp_size den_size = src->den.size;
-
- if (num_size == 0)
- num_size = 1 / num_size; /* Divide by zero! */
-
- if (num_size < 0)
- {
- num_size = -num_size;
- den_size = -den_size;
- }
- dest->den.size = num_size;
- dest->num.size = den_size;
-
- /* If dest == src we may just swap the numerator and denominator, but
- we have to ensure the new denominator is positive. */
-
- if (dest == src)
- {
- mp_size alloc = dest->num.alloc;
- mp_ptr limb_ptr = dest->num.d;
-
- dest->num.alloc = dest->den.alloc;
- dest->num.d = dest->den.d;
-
- dest->den.alloc = alloc;
- dest->den.d = limb_ptr;
- }
- else
- {
- den_size = ABS (den_size);
- if (dest->num.alloc < den_size)
- _mpz_realloc (&(dest->num), den_size);
-
- if (dest->den.alloc < num_size)
- _mpz_realloc (&(dest->den), num_size);
-
- MPN_COPY (dest->num.d, src->den.d, den_size);
- MPN_COPY (dest->den.d, src->num.d, num_size);
- }
-}