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/* mpfr_check -- Check if a floating-point number has not been corrupted.
Copyright 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
Contributed by the AriC and Caramel 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"
/*
* Check if x is a valid mpfr_t initializes by mpfr_init
* Returns 0 if isn't valid
*/
int
mpfr_check (mpfr_srcptr x)
{
mp_size_t s, i;
mp_limb_t tmp;
volatile mp_limb_t *xm;
mpfr_prec_t prec;
int rw;
/* Check sign */
if (MPFR_SIGN(x) != MPFR_SIGN_POS &&
MPFR_SIGN(x) != MPFR_SIGN_NEG)
return 0;
/* Check precision */
prec = MPFR_PREC(x);
if (prec < MPFR_PREC_MIN ||
prec > MPFR_PREC_MAX)
return 0;
/* Check mantissa */
xm = MPFR_MANT(x);
if (xm == NULL)
return 0;
/* Check size of mantissa */
s = MPFR_GET_ALLOC_SIZE(x);
if (s <= 0 || s > MP_SIZE_T_MAX ||
prec > (mpfr_prec_t) s * GMP_NUMB_BITS)
return 0;
/* Acces all the mp_limb of the mantissa: may do a seg fault */
for (i = 0 ; i < s ; i++)
tmp = xm[i];
/* Check singular numbers (do not use MPFR_IS_PURE_FP() in order to avoid
any assertion checking, as this function mpfr_check() does something
similar by returning a Boolean instead of doing an abort if the format
is incorrect). */
if (MPFR_IS_SINGULAR (x))
return MPFR_IS_ZERO(x) || MPFR_IS_NAN(x) || MPFR_IS_INF(x);
/* Check the most significant limb (its MSB must be 1) */
if ((xm[MPFR_LAST_LIMB(x)] & MPFR_LIMB_HIGHBIT) == 0)
return 0;
/* Check the least significant limb (the trailing bits must be 0) */
rw = prec % GMP_NUMB_BITS;
if (rw != 0)
{
tmp = MPFR_LIMB_MASK (GMP_NUMB_BITS - rw);
if ((xm[0] & tmp) != 0)
return 0;
}
/* Check exponent range */
if (MPFR_EXP (x) < __gmpfr_emin ||
MPFR_EXP (x) > __gmpfr_emax)
return 0;
return 1;
}
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