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      1 /* mpf_div_ui -- Divide a float with an unsigned integer.
      2 
      3 Copyright 1993, 1994, 1996, 2000-2002, 2004, 2005, 2012 Free Software
      4 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 #include "longlong.h"
     34 
     35 void
     36 mpf_div_ui (mpf_ptr r, mpf_srcptr u, unsigned long int v)
     37 {
     38   mp_srcptr up;
     39   mp_ptr rp, tp, rtp;
     40   mp_size_t usize;
     41   mp_size_t rsize, tsize;
     42   mp_size_t sign_quotient;
     43   mp_size_t prec;
     44   mp_limb_t q_limb;
     45   mp_exp_t rexp;
     46   TMP_DECL;
     47 
     48 #if BITS_PER_ULONG > GMP_NUMB_BITS  /* avoid warnings about shift amount */
     49   if (v > GMP_NUMB_MAX)
     50     {
     51       mpf_t vf;
     52       mp_limb_t vl[2];
     53       SIZ(vf) = 2;
     54       EXP(vf) = 2;
     55       PTR(vf) = vl;
     56       vl[0] = v & GMP_NUMB_MASK;
     57       vl[1] = v >> GMP_NUMB_BITS;
     58       mpf_div (r, u, vf);
     59       return;
     60     }
     61 #endif
     62 
     63   if (UNLIKELY (v == 0))
     64     DIVIDE_BY_ZERO;
     65 
     66   usize = u->_mp_size;
     67 
     68   if (usize == 0)
     69     {
     70       r->_mp_size = 0;
     71       r->_mp_exp = 0;
     72       return;
     73     }
     74 
     75   sign_quotient = usize;
     76   usize = ABS (usize);
     77   prec = r->_mp_prec;
     78 
     79   TMP_MARK;
     80 
     81   rp = r->_mp_d;
     82   up = u->_mp_d;
     83 
     84   tsize = 1 + prec;
     85   tp = TMP_ALLOC_LIMBS (tsize + 1);
     86 
     87   if (usize > tsize)
     88     {
     89       up += usize - tsize;
     90       usize = tsize;
     91       rtp = tp;
     92     }
     93   else
     94     {
     95       MPN_ZERO (tp, tsize - usize);
     96       rtp = tp + (tsize - usize);
     97     }
     98 
     99   /* Move the dividend to the remainder.  */
    100   MPN_COPY (rtp, up, usize);
    101 
    102   mpn_divmod_1 (rp, tp, tsize, (mp_limb_t) v);
    103   q_limb = rp[tsize - 1];
    104 
    105   rsize = tsize - (q_limb == 0);
    106   rexp = u->_mp_exp - (q_limb == 0);
    107   r->_mp_size = sign_quotient >= 0 ? rsize : -rsize;
    108   r->_mp_exp = rexp;
    109   TMP_FREE;
    110 }
    111