github.com/aergoio/aergo@v1.3.1/libtool/src/gmp-6.1.2/mpz/tdiv_qr.c (about)

     1  /* mpz_tdiv_qr(quot,rem,dividend,divisor) -- Set QUOT to DIVIDEND/DIVISOR,
     2     and REM to DIVIDEND mod DIVISOR.
     3  
     4  Copyright 1991, 1993, 1994, 2000, 2001, 2005, 2011, 2012 Free Software
     5  Foundation, Inc.
     6  
     7  This file is part of the GNU MP Library.
     8  
     9  The GNU MP Library is free software; you can redistribute it and/or modify
    10  it under the terms of either:
    11  
    12    * the GNU Lesser General Public License as published by the Free
    13      Software Foundation; either version 3 of the License, or (at your
    14      option) any later version.
    15  
    16  or
    17  
    18    * the GNU General Public License as published by the Free Software
    19      Foundation; either version 2 of the License, or (at your option) any
    20      later version.
    21  
    22  or both in parallel, as here.
    23  
    24  The GNU MP Library is distributed in the hope that it will be useful, but
    25  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    26  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    27  for more details.
    28  
    29  You should have received copies of the GNU General Public License and the
    30  GNU Lesser General Public License along with the GNU MP Library.  If not,
    31  see https://www.gnu.org/licenses/.  */
    32  
    33  #include "gmp.h"
    34  #include "gmp-impl.h"
    35  #include "longlong.h"
    36  
    37  void
    38  mpz_tdiv_qr (mpz_ptr quot, mpz_ptr rem, mpz_srcptr num, mpz_srcptr den)
    39  {
    40    mp_size_t ql;
    41    mp_size_t ns, ds, nl, dl;
    42    mp_ptr np, dp, qp, rp;
    43    TMP_DECL;
    44  
    45    ns = SIZ (num);
    46    ds = SIZ (den);
    47    nl = ABS (ns);
    48    dl = ABS (ds);
    49    ql = nl - dl + 1;
    50  
    51    if (UNLIKELY (dl == 0))
    52      DIVIDE_BY_ZERO;
    53  
    54    rp = MPZ_REALLOC (rem, dl);
    55  
    56    if (ql <= 0)
    57      {
    58        if (num != rem)
    59  	{
    60  	  np = PTR (num);
    61  	  MPN_COPY (rp, np, nl);
    62  	  SIZ (rem) = SIZ (num);
    63  	}
    64        /* This needs to follow the assignment to rem, in case the
    65  	 numerator and quotient are the same.  */
    66        SIZ (quot) = 0;
    67        return;
    68      }
    69  
    70    qp = MPZ_REALLOC (quot, ql);
    71  
    72    TMP_MARK;
    73    np = PTR (num);
    74    dp = PTR (den);
    75  
    76    /* FIXME: We should think about how to handle the temporary allocation.
    77       Perhaps mpn_tdiv_qr should handle it, since it anyway often needs to
    78       allocate temp space.  */
    79  
    80    /* Copy denominator to temporary space if it overlaps with the quotient
    81       or remainder.  */
    82    if (dp == rp || dp == qp)
    83      {
    84        mp_ptr tp;
    85        tp = TMP_ALLOC_LIMBS (dl);
    86        MPN_COPY (tp, dp, dl);
    87        dp = tp;
    88      }
    89    /* Copy numerator to temporary space if it overlaps with the quotient or
    90       remainder.  */
    91    if (np == rp || np == qp)
    92      {
    93        mp_ptr tp;
    94        tp = TMP_ALLOC_LIMBS (nl);
    95        MPN_COPY (tp, np, nl);
    96        np = tp;
    97      }
    98  
    99    mpn_tdiv_qr (qp, rp, 0L, np, nl, dp, dl);
   100  
   101    ql -=  qp[ql - 1] == 0;
   102    MPN_NORMALIZE (rp, dl);
   103  
   104    SIZ (quot) = (ns ^ ds) >= 0 ? ql : -ql;
   105    SIZ (rem) = ns >= 0 ? dl : -dl;
   106    TMP_FREE;
   107  }