1/* mpfr_set -- copy of a floating-point number 2 3Copyright 1999, 2001, 2002, 2003, 2004, 2005, 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 25/* set a to abs(b) * signb: a=b when signb = SIGN(b), a=abs(b) when signb=1 */ 26int 27mpfr_set4 (mpfr_ptr a, mpfr_srcptr b, mpfr_rnd_t rnd_mode, int signb) 28{ 29 /* Sign is ALWAYS copied */ 30 MPFR_SET_SIGN (a, signb); 31 32 /* Exponent is also always copied since if the number is singular, 33 the exponent field determined the number. 34 Can't use MPFR_SET_EXP since the exponent may be singular */ 35 MPFR_EXP (a) = MPFR_EXP (b); 36 37 if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (b))) 38 { 39 /* MPFR_SET_NAN, MPFR_SET_ZERO and MPFR_SET_INF are useless 40 since MPFR_EXP (a) = MPFR_EXP (b) does the job */ 41 if (MPFR_IS_NAN (b)) 42 MPFR_RET_NAN; 43 else 44 MPFR_RET (0); 45 } 46 else if (MPFR_LIKELY (MPFR_PREC (b) == MPFR_PREC (a))) 47 { 48 /* Same precision and b is not singular: 49 * just copy the mantissa, and set the exponent and the sign 50 * The result is exact. */ 51 MPN_COPY (MPFR_MANT (a), MPFR_MANT (b), MPFR_LIMB_SIZE (b)); 52 MPFR_RET (0); 53 } 54 else 55 { 56 int inex; 57 58 /* Else Round B inside a */ 59 MPFR_RNDRAW (inex, a, MPFR_MANT (b), MPFR_PREC (b), rnd_mode, signb, 60 if (MPFR_UNLIKELY ( ++MPFR_EXP (a) > __gmpfr_emax)) 61 return mpfr_overflow (a, rnd_mode, signb) ); 62 MPFR_RET (inex); 63 } 64} 65 66/* Set a to b */ 67#undef mpfr_set 68int 69mpfr_set (mpfr_ptr a, mpfr_srcptr b, mpfr_rnd_t rnd_mode) 70{ 71 return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN (b)); 72} 73 74/* Set a to |b| */ 75#undef mpfr_abs 76int 77mpfr_abs (mpfr_ptr a, mpfr_srcptr b, mpfr_rnd_t rnd_mode) 78{ 79 return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN_POS); 80} 81