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/* 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 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.
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 Lesser General Public
License for more details.
You should have received a copy of 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;
}
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