diff options
Diffstat (limited to 'vendor/gmp-6.3.0/mpq/inv.c')
-rw-r--r-- | vendor/gmp-6.3.0/mpq/inv.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/mpq/inv.c b/vendor/gmp-6.3.0/mpq/inv.c new file mode 100644 index 0000000..c395984 --- /dev/null +++ b/vendor/gmp-6.3.0/mpq/inv.c @@ -0,0 +1,70 @@ +/* mpq_inv(dest,src) -- invert a rational number, i.e. set DEST to SRC + with the numerator and denominator swapped. + +Copyright 1991, 1994, 1995, 2000, 2001, 2012 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 either: + + * 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. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +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 copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://www.gnu.org/licenses/. */ + +#include "gmp-impl.h" + +void +mpq_inv (mpq_ptr dest, mpq_srcptr src) +{ + mp_size_t num_size = SIZ(NUM(src)); + mp_size_t den_size = SIZ(DEN(src)); + + if (num_size < 0) + { + num_size = -num_size; + den_size = -den_size; + } + else if (UNLIKELY (num_size == 0)) + DIVIDE_BY_ZERO; + + SIZ(DEN(dest)) = num_size; + SIZ(NUM(dest)) = den_size; + + /* If dest == src we may just swap the numerator and denominator; + we ensured that the new denominator is positive. */ + + if (dest == src) + { + MP_PTR_SWAP (PTR(NUM(dest)), PTR(DEN(dest))); + MP_SIZE_T_SWAP (ALLOC(NUM(dest)), ALLOC(DEN(dest))); + } + else + { + mp_ptr dp; + + den_size = ABS (den_size); + dp = MPZ_NEWALLOC (NUM(dest), den_size); + MPN_COPY (dp, PTR(DEN(src)), den_size); + + dp = MPZ_NEWALLOC (DEN(dest), num_size); + MPN_COPY (dp, PTR(NUM(src)), num_size); + } +} |