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88896a1144
Change-Id: I42dc2a783b3e0082a7583cc7ecaa6b043ba162f4 Reviewed-on: https://review.haiku-os.org/c/buildtools/+/3021 Reviewed-by: Fredrik Holmqvist <fredrik.holmqvist@gmail.com>
82 lines
2.7 KiB
C
82 lines
2.7 KiB
C
/* mpfr_check -- Check if a floating-point number has not been corrupted.
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Copyright 2003-2004, 2006-2020 Free Software Foundation, Inc.
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Contributed by the AriC and Caramba projects, INRIA.
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This file is part of the GNU MPFR Library.
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The GNU MPFR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 3 of the License, or (at your
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option) any later version.
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The GNU MPFR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
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https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
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51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
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#include "mpfr-impl.h"
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/*
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* Check if x is a valid mpfr_t initialized by mpfr_init
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* Returns 0 if isn't valid
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*
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* Note: Due to the MPFR_GET_ALLOC_SIZE test, this function must not
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* be called on statically allocated numbers (only used inside MPFR).
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* Anyway, this test should not be useful on such numbers.
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*/
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int
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mpfr_check (mpfr_srcptr x)
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{
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mp_size_t s, i;
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mp_limb_t tmp;
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volatile mp_limb_t *xm;
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mpfr_prec_t prec;
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int rw;
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/* Check sign */
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if (MPFR_SIGN(x) != MPFR_SIGN_POS &&
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MPFR_SIGN(x) != MPFR_SIGN_NEG)
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return 0;
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/* Check precision */
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prec = MPFR_PREC(x);
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if (! MPFR_PREC_COND (prec))
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return 0;
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/* Check mantissa */
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xm = MPFR_MANT(x);
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if (xm == NULL)
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return 0;
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/* Check size of mantissa */
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s = MPFR_GET_ALLOC_SIZE(x);
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if (s <= 0 || s > MP_SIZE_T_MAX ||
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prec > (mpfr_prec_t) s * GMP_NUMB_BITS)
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return 0;
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/* Access all the mp_limb of the mantissa: may do a seg fault */
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for (i = 0 ; i < s ; i++)
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tmp = xm[i];
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/* Check singular numbers (do not use MPFR_IS_PURE_FP() in order to avoid
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any assertion checking, as this function mpfr_check() does something
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similar by returning a Boolean instead of doing an abort if the format
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is incorrect). */
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if (MPFR_IS_SINGULAR (x))
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return MPFR_IS_ZERO(x) || MPFR_IS_NAN(x) || MPFR_IS_INF(x);
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/* Check the most significant limb (its MSB must be 1) */
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if (! MPFR_IS_NORMALIZED (x))
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return 0;
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/* Check the least significant limb (the trailing bits must be 0) */
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rw = prec % GMP_NUMB_BITS;
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if (rw != 0)
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{
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tmp = MPFR_LIMB_MASK (GMP_NUMB_BITS - rw);
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if ((xm[0] & tmp) != 0)
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return 0;
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}
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/* Check exponent range */
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return MPFR_EXP_IN_RANGE (MPFR_EXP (x));
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}
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