| /* mpfr_get_z_exp -- get a multiple-precision integer from |
| a floating-point number |
| |
| Copyright 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. |
| Contributed by the Arenaire and Cacao 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 2.1 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.LIB. If not, write to |
| the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, |
| MA 02110-1301, USA. */ |
| |
| #include "mpfr-impl.h" |
| |
| void |
| mpfr_get_z (mpz_ptr z, mpfr_srcptr f, mp_rnd_t rnd) |
| { |
| mpfr_t r; |
| mp_exp_t exp = MPFR_EXP (f); |
| |
| /* if exp <= 0, then |f|<1, thus |o(f)|<=1 */ |
| MPFR_ASSERTD (MPFR_PREC_MIN == 2); |
| mpfr_init2 (r, (exp <= 0) ? MPFR_PREC_MIN : exp + 1); |
| mpfr_rint (r, f, rnd); |
| MPFR_ASSERTN (MPFR_IS_FP (r) ); |
| exp = mpfr_get_z_exp (z, r); |
| /* FIXME: It seems that exp < 0 is always true */ |
| if (exp >= 0) |
| mpz_mul_2exp (z, z, exp); |
| else |
| mpz_div_2exp (z, z, -exp); |
| mpfr_clear (r); |
| } |