/* mpf_ui_div -- Divide an unsigned integer with a float.

Copyright 1993-1996, 2000-2002, 2004, 2005, 2012 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify

it under the terms of either:

  * the GNU Lesser General Public License as published by the Free

    Software Foundation; either version 3 of the License, or (at your

    option) any later version.

or

  * the GNU General Public License as published by the Free Software

    Foundation; either version 2 of the License, or (at your option) any

    later version.

or both in parallel, as here.

The GNU MP Library is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

for more details.

You should have received copies of the GNU General Public License and the

GNU Lesser General Public License along with the GNU MP Library.  If not,

see https://www.gnu.org/licenses/.  */

#include <stdio.h>  /* for NULL */

#include "gmp.h"

#include "gmp-impl.h"

#include "longlong.h"

void

mpf_ui_div (mpf_ptr r, unsigned long int u, mpf_srcptr v)

{

  mp_srcptr vp;

  mp_ptr rp, tp, remp, new_vp;

  mp_size_t vsize;

  mp_size_t rsize, prospective_rsize, zeros, tsize, high_zero;

  mp_size_t sign_quotient;

  mp_size_t prec;

  mp_exp_t rexp;

  TMP_DECL;

  vsize = v->_mp_size;

  sign_quotient = vsize;

  if (UNLIKELY (vsize == 0))

    DIVIDE_BY_ZERO;

  if (UNLIKELY (u == 0))

    {

      r->_mp_size = 0;

      r->_mp_exp = 0;

      return;

    }

  vsize = ABS (vsize);

  prec = r->_mp_prec;

  TMP_MARK;

  rexp = 1 - v->_mp_exp + 1;

  rp = r->_mp_d;

  vp = v->_mp_d;

  prospective_rsize = 1 - vsize + 1;    /* quot from using given u,v sizes */

  rsize = prec + 1;                     /* desired quot size */

  zeros = rsize - prospective_rsize;    /* padding u to give rsize */

  tsize = 1 + zeros;                    /* u with zeros */

  if (WANT_TMP_DEBUG)

    {

      /* separate alloc blocks, for malloc debugging */

      remp = TMP_ALLOC_LIMBS (vsize);

      tp = TMP_ALLOC_LIMBS (tsize);

      new_vp = NULL;

      if (rp == vp)

        new_vp = TMP_ALLOC_LIMBS (vsize);

    }

  else

    {

      /* one alloc with calculated size, for efficiency */

      mp_size_t size = vsize + tsize + (rp == vp ? vsize : 0);

      remp = TMP_ALLOC_LIMBS (size);

      tp = remp + vsize;

      new_vp = tp + tsize;

    }

  /* ensure divisor doesn't overlap quotient */

  if (rp == vp)

    {

      MPN_COPY (new_vp, vp, vsize);

      vp = new_vp;

    }

  MPN_ZERO (tp, tsize-1);

  tp[tsize - 1] = u & GMP_NUMB_MASK;

#if BITS_PER_ULONG > GMP_NUMB_BITS

  if (u > GMP_NUMB_MAX)

    {

      /* tsize-vsize+1 == rsize, so tsize >= rsize.  rsize == prec+1 >= 2,

         so tsize >= 2, hence there's room for 2-limb u with nails */

      ASSERT (tsize >= 2);

      tp[tsize - 1] = u >> GMP_NUMB_BITS;

      tp[tsize - 2] = u & GMP_NUMB_MASK;

      rexp++;

    }

#endif

  ASSERT (tsize-vsize+1 == rsize);

  mpn_tdiv_qr (rp, remp, (mp_size_t) 0, tp, tsize, vp, vsize);

  /* strip possible zero high limb */

  high_zero = (rp[rsize-1] == 0);

  rsize -= high_zero;

  rexp -= high_zero;

  r->_mp_size = sign_quotient >= 0 ? rsize : -rsize;

  r->_mp_exp = rexp;

  TMP_FREE;

}