1  /* mpz_fdiv_qr -- Division rounding the quotient towards -infinity.
       2     The remainder gets the same sign as the denominator.
       3  
       4  Copyright 1994-1996, 2000, 2001, 2005, 2012 Free Software Foundation, Inc.
       5  
       6  This file is part of the GNU MP Library.
       7  
       8  The GNU MP Library is free software; you can redistribute it and/or modify
       9  it under the terms of either:
      10  
      11    * the GNU Lesser General Public License as published by the Free
      12      Software Foundation; either version 3 of the License, or (at your
      13      option) any later version.
      14  
      15  or
      16  
      17    * the GNU General Public License as published by the Free Software
      18      Foundation; either version 2 of the License, or (at your option) any
      19      later version.
      20  
      21  or both in parallel, as here.
      22  
      23  The GNU MP Library is distributed in the hope that it will be useful, but
      24  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      25  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      26  for more details.
      27  
      28  You should have received copies of the GNU General Public License and the
      29  GNU Lesser General Public License along with the GNU MP Library.  If not,
      30  see https://www.gnu.org/licenses/.  */
      31  
      32  #include "gmp-impl.h"
      33  
      34  void
      35  mpz_fdiv_qr (mpz_ptr quot, mpz_ptr rem, mpz_srcptr dividend, mpz_srcptr divisor)
      36  {
      37    mp_size_t divisor_size = SIZ (divisor);
      38    mp_size_t xsize;
      39    mpz_t temp_divisor;		/* N.B.: lives until function returns! */
      40    TMP_DECL;
      41  
      42    TMP_MARK;
      43  
      44    /* We need the original value of the divisor after the quotient and
      45       remainder have been preliminary calculated.  We have to copy it to
      46       temporary space if it's the same variable as either QUOT or REM.  */
      47    if (quot == divisor || rem == divisor)
      48      {
      49        MPZ_TMP_INIT (temp_divisor, ABS (divisor_size));
      50        mpz_set (temp_divisor, divisor);
      51        divisor = temp_divisor;
      52      }
      53  
      54    xsize = SIZ (dividend) ^ divisor_size;;
      55    mpz_tdiv_qr (quot, rem, dividend, divisor);
      56  
      57    if (xsize < 0 && SIZ (rem) != 0)
      58      {
      59        mpz_sub_ui (quot, quot, 1L);
      60        mpz_add (rem, rem, divisor);
      61      }
      62  
      63    TMP_FREE;
      64  }