1/* mpfr_set_prec -- reset the precision of a floating-point number 2 3Copyright 1999, 2001, 2002, 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. 4Contributed by the AriC and Caramel projects, INRIA. 5 6This file is part of the GNU MPFR Library. 7 8The GNU MPFR Library is free software; you can redistribute it and/or modify 9it under the terms of the GNU Lesser General Public License as published by 10the Free Software Foundation; either version 3 of the License, or (at your 11option) any later version. 12 13The GNU MPFR Library is distributed in the hope that it will be useful, but 14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 15or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 16License for more details. 17 18You should have received a copy of the GNU Lesser General Public License 19along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see 20http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 2151 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ 22 23#include "mpfr-impl.h" 24 25void 26mpfr_set_prec (mpfr_ptr x, mpfr_prec_t p) 27{ 28 mp_size_t xsize, xoldsize; 29 mpfr_limb_ptr tmp; 30 31 /* first, check if p is correct */ 32 MPFR_ASSERTN (p >= MPFR_PREC_MIN && p <= MPFR_PREC_MAX); 33 34 /* Calculate the new number of limbs */ 35 xsize = MPFR_PREC2LIMBS (p); 36 37 /* Realloc only if the new size is greater than the old */ 38 xoldsize = MPFR_GET_ALLOC_SIZE (x); 39 if (xsize > xoldsize) 40 { 41 tmp = (mpfr_limb_ptr) (*__gmp_reallocate_func) 42 (MPFR_GET_REAL_PTR(x), MPFR_MALLOC_SIZE(xoldsize), MPFR_MALLOC_SIZE(xsize)); 43 MPFR_SET_MANT_PTR(x, tmp); 44 MPFR_SET_ALLOC_SIZE(x, xsize); 45 } 46 MPFR_PREC (x) = p; 47 MPFR_SET_NAN (x); /* initializes to NaN */ 48} 49 50#undef mpfr_get_prec 51mpfr_prec_t 52mpfr_get_prec (mpfr_srcptr x) 53{ 54 return MPFR_PREC(x); 55} 56