1  /* mpz_set_f (dest_integer, src_float) -- Assign DEST_INTEGER from SRC_FLOAT.
       2  
       3  Copyright 1996, 2001, 2012, 2016 Free Software Foundation, Inc.
       4  
       5  This file is part of the GNU MP Library.
       6  
       7  The GNU MP Library is free software; you can redistribute it and/or modify
       8  it under the terms of either:
       9  
      10    * the GNU Lesser General Public License as published by the Free
      11      Software Foundation; either version 3 of the License, or (at your
      12      option) any later version.
      13  
      14  or
      15  
      16    * the GNU General Public License as published by the Free Software
      17      Foundation; either version 2 of the License, or (at your option) any
      18      later version.
      19  
      20  or both in parallel, as here.
      21  
      22  The GNU MP Library is distributed in the hope that it will be useful, but
      23  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      24  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      25  for more details.
      26  
      27  You should have received copies of the GNU General Public License and the
      28  GNU Lesser General Public License along with the GNU MP Library.  If not,
      29  see https://www.gnu.org/licenses/.  */
      30  
      31  #include "gmp-impl.h"
      32  
      33  
      34  void
      35  mpz_set_f (mpz_ptr w, mpf_srcptr u)
      36  {
      37    mp_ptr    wp, up;
      38    mp_size_t size;
      39    mp_exp_t  exp;
      40  
      41    /* abs(u)<1 truncates to zero */
      42    exp = EXP (u);
      43    if (exp <= 0)
      44      {
      45        SIZ(w) = 0;
      46        return;
      47      }
      48  
      49    wp = MPZ_NEWALLOC (w, exp);
      50    up = PTR(u);
      51  
      52    size = SIZ (u);
      53    SIZ(w) = (size >= 0 ? exp : -exp);
      54    size = ABS (size);
      55  
      56    if (exp > size)
      57      {
      58        /* pad with low zeros to get a total "exp" many limbs */
      59        mp_size_t  zeros = exp - size;
      60        MPN_ZERO (wp, zeros);
      61        wp += zeros;
      62      }
      63    else
      64      {
      65        /* exp<=size, truncate to the high "exp" many limbs */
      66        up += (size - exp);
      67        size = exp;
      68      }
      69  
      70    MPN_COPY (wp, up, size);
      71  }