1/* mpfr_check -- Check if a floating-point number has not been corrupted. 2 3Copyright 2003, 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 25/* 26 * Check if x is a valid mpfr_t initializes by mpfr_init 27 * Returns 0 if isn't valid 28 */ 29int 30mpfr_check (mpfr_srcptr x) 31{ 32 mp_size_t s, i; 33 mp_limb_t tmp; 34 volatile mp_limb_t *xm; 35 int rw; 36 37 /* Check Sign */ 38 if (MPFR_SIGN(x) != MPFR_SIGN_POS && MPFR_SIGN(x) != MPFR_SIGN_NEG) 39 return 0; 40 /* Check Precision */ 41 if ( (MPFR_PREC(x) < MPFR_PREC_MIN) || (MPFR_PREC(x) > MPFR_PREC_MAX)) 42 return 0; 43 /* Check Mantissa */ 44 xm = MPFR_MANT(x); 45 if (!xm) 46 return 0; 47 /* Check size of mantissa */ 48 s = MPFR_GET_ALLOC_SIZE(x); 49 if (s<=0 || s > MP_SIZE_T_MAX || 50 MPFR_PREC(x) > ((mpfr_prec_t)s*GMP_NUMB_BITS)) 51 return 0; 52 /* Acces all the mp_limb of the mantissa: may do a seg fault */ 53 for(i = 0 ; i < s ; i++) 54 tmp = xm[i]; 55 /* Check if it isn't singular*/ 56 if (! MPFR_IS_SINGULAR (x)) 57 { 58 /* Check first mp_limb of mantissa (Must start with a 1 bit) */ 59 if ( ((xm[MPFR_LIMB_SIZE(x)-1])>>(GMP_NUMB_BITS-1)) == 0) 60 return 0; 61 /* Check last mp_limb of mantissa */ 62 rw = (MPFR_PREC(x) % GMP_NUMB_BITS); 63 if (rw != 0) 64 { 65 tmp = MPFR_LIMB_MASK (GMP_NUMB_BITS - rw); 66 if ((xm[0] & tmp) != 0) 67 return 0; 68 } 69 /* Check exponent range */ 70 if ((MPFR_EXP (x) < __gmpfr_emin) || (MPFR_EXP (x) > __gmpfr_emax)) 71 return 0; 72 } 73 else 74 { 75 /* Singular value is zero, inf or nan */ 76 MPFR_ASSERTD(MPFR_IS_ZERO(x) || MPFR_IS_NAN(x) || MPFR_IS_INF(x)); 77 } 78 return 1; 79} 80 81