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/* mpfr_check -- Check if a floating-point number has not been corrupted.
Copyright 2003, 2004 Free Software Foundation, Inc.
This file is part of the MPFR Library.
The 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 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 MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Place, 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;
int rw;
/* Check Sign */
if (MPFR_SIGN(x) != MPFR_SIGN_POS && MPFR_SIGN(x) != MPFR_SIGN_NEG)
return 0;
/* Check Precision */
if ( (MPFR_PREC(x) < MPFR_PREC_MIN) || (MPFR_PREC(x) > MPFR_PREC_MAX))
return 0;
/* Check Mantissa */
xm = MPFR_MANT(x);
if (!xm)
return 0;
/* Check size of mantissa */
s = MPFR_GET_ALLOC_SIZE(x);
if (s<=0 || s > MP_SIZE_T_MAX ||
MPFR_PREC(x) > ((mp_prec_t)s*BITS_PER_MP_LIMB))
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 if it isn't singular*/
if (MPFR_IS_PURE_FP(x))
{
/* Check first mp_limb of mantissa (Must start with a 1 bit) */
if ( ((xm[MPFR_LIMB_SIZE(x)-1])>>(BITS_PER_MP_LIMB-1)) == 0)
return 0;
/* Check last mp_limb of mantissa */
rw = (MPFR_PREC(x) % BITS_PER_MP_LIMB);
if (rw != 0)
{
tmp = MPFR_LIMB_MASK (BITS_PER_MP_LIMB - rw);
if ((xm[0] & tmp) != 0)
return 0;
}
/* Check exponent range */
if ((MPFR_EXP (x) < __gmpfr_emin) || (MPFR_EXP (x) > __gmpfr_emax))
return 0;
}
else
{
/* Singular value is zero, inf or nan */
MPFR_ASSERTD(MPFR_IS_ZERO(x) || MPFR_IS_NAN(x) || MPFR_IS_INF(x));
}
return 1;
}
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