Coverage Report

Created: 2023-02-22 06:39

/src/gmp-6.2.1/mpz/divexact.c
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/* mpz_divexact -- finds quotient when known that quot * den == num && den != 0.
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Contributed to the GNU project by Niels Möller.
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Copyright 1991, 1993-1998, 2000-2002, 2005-2007, 2009, 2012 Free Software
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Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of either:
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  * the GNU Lesser General Public License as published by the Free
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    Software Foundation; either version 3 of the License, or (at your
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    option) any later version.
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or
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  * the GNU General Public License as published by the Free Software
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    Foundation; either version 2 of the License, or (at your option) any
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    later version.
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or both in parallel, as here.
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The GNU MP 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 General Public License
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for more details.
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You should have received copies of the GNU General Public License and the
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GNU Lesser General Public License along with the GNU MP Library.  If not,
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see https://www.gnu.org/licenses/.  */
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#include "gmp-impl.h"
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void
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mpz_divexact (mpz_ptr quot, mpz_srcptr num, mpz_srcptr den)
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{
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  mp_ptr qp;
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  mp_size_t qn;
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  mp_srcptr np, dp;
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  mp_size_t nn, dn;
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  TMP_DECL;
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#if WANT_ASSERT
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  {
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    mpz_t  rem;
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    mpz_init (rem);
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    mpz_tdiv_r (rem, num, den);
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    ASSERT (SIZ(rem) == 0);
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    mpz_clear (rem);
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  }
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#endif
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  nn = ABSIZ (num);
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  dn = ABSIZ (den);
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  if (nn < dn)
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1
    {
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      /* This special case avoids segfaults below when the function is
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   incorrectly called with |N| < |D|, N != 0.  It also handles the
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   well-defined case N = 0.  */
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      SIZ(quot) = 0;
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      return;
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1
    }
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  qn = nn - dn + 1;
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  TMP_MARK;
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  if (quot == num || quot == den)
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    qp = TMP_ALLOC_LIMBS (qn);
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  else
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    qp = MPZ_NEWALLOC (quot, qn);
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  np = PTR(num);
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  dp = PTR(den);
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  mpn_divexact (qp, np, nn, dp, dn);
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  MPN_NORMALIZE (qp, qn);
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  if (qp != PTR(quot))
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    MPN_COPY (MPZ_NEWALLOC (quot, qn), qp, qn);
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  SIZ(quot) = (SIZ(num) ^ SIZ(den)) >= 0 ? qn : -qn;
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  TMP_FREE;
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}