diff options
Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/get_q.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-src/src/get_q.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/get_q.c b/Build/source/libs/mpfr/mpfr-src/src/get_q.c new file mode 100644 index 00000000000..8cc2bc02b9c --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-src/src/get_q.c @@ -0,0 +1,63 @@ +/* mpfr_get_q -- get a multiple-precision rational from + a floating-point number + +Copyright 2004, 2006-2017 Free Software Foundation, Inc. +Contributed by the AriC and Caramba projects, INRIA. + +This file is part of the GNU MPFR Library. + +The GNU MPFR 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 MPFR 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 MPFR Library; see the file COPYING.LESSER. If not, see +http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., +51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#include "mpfr-impl.h" + +#ifndef MPFR_USE_MINI_GMP +/* part of the code was copied from get_z.c */ +void +mpfr_get_q (mpq_ptr q, mpfr_srcptr f) +{ + mpfr_exp_t exp; + mpz_ptr u = mpq_numref (q); + mpz_ptr v = mpq_denref (q); + + /* v is set to 1 and will not be changed directly. + This ensures that q will be canonical. */ + mpz_set_ui (v, 1); + + if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (f))) + { + if (MPFR_UNLIKELY (MPFR_NOTZERO (f))) + MPFR_SET_ERANGEFLAG (); + mpz_set_ui (u, 0); + /* The ternary value is 0 even for infinity. Giving the rounding + direction in this case would not make much sense anyway, and + the direction would not necessarily match rnd. */ + } + else + { + exp = mpfr_get_z_2exp (u, f); + if (exp >= 0) + { + MPFR_ASSERTN (exp <= (mp_bitcnt_t) -1); + mpz_mul_2exp (u, u, exp); + } + else /* exp < 0 */ + { + MPFR_ASSERTN (-exp <= (mp_bitcnt_t) -1); + mpq_div_2exp (q, q, -exp); + } + } +} +#endif |