aa9bc17601
BMakefiles and other bits will follow. Requested by: Andrey Chernov Made world by: Chuck Robey
132 lines
3.3 KiB
C
132 lines
3.3 KiB
C
/* mpf_ui_div -- Divide an unsigned integer with a float.
|
|
|
|
Copyright (C) 1993, 1994, 1995, 1996 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 Library General Public License as published by
|
|
the Free Software Foundation; either version 2 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 Library General Public
|
|
License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public License
|
|
along with the GNU MP Library; see the file COPYING.LIB. If not, write to
|
|
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
|
|
MA 02111-1307, USA. */
|
|
|
|
#include "gmp.h"
|
|
#include "gmp-impl.h"
|
|
#include "longlong.h"
|
|
|
|
void
|
|
#if __STDC__
|
|
mpf_ui_div (mpf_ptr r, unsigned long int u, mpf_srcptr v)
|
|
#else
|
|
mpf_ui_div (r, u, v)
|
|
mpf_ptr r;
|
|
unsigned long int u;
|
|
mpf_srcptr v;
|
|
#endif
|
|
{
|
|
mp_srcptr vp;
|
|
mp_ptr rp, tp;
|
|
mp_size_t vsize;
|
|
mp_size_t rsize, tsize;
|
|
mp_size_t sign_quotient;
|
|
mp_size_t prec;
|
|
unsigned normalization_steps;
|
|
mp_limb_t q_limb;
|
|
mp_exp_t rexp;
|
|
TMP_DECL (marker);
|
|
|
|
vsize = v->_mp_size;
|
|
sign_quotient = vsize;
|
|
vsize = ABS (vsize);
|
|
prec = r->_mp_prec;
|
|
|
|
if (vsize == 0)
|
|
vsize = 1 / vsize; /* divide by zero as directed */
|
|
if (u == 0)
|
|
{
|
|
r->_mp_size = 0;
|
|
r->_mp_exp = 0;
|
|
return;
|
|
}
|
|
|
|
TMP_MARK (marker);
|
|
rexp = 1 - v->_mp_exp;
|
|
|
|
rp = r->_mp_d;
|
|
vp = v->_mp_d;
|
|
|
|
if (vsize > prec)
|
|
{
|
|
vp += vsize - prec;
|
|
vsize = prec;
|
|
}
|
|
|
|
tsize = vsize + prec;
|
|
tp = (mp_ptr) TMP_ALLOC ((tsize + 1) * BYTES_PER_MP_LIMB);
|
|
MPN_ZERO (tp, tsize);
|
|
|
|
count_leading_zeros (normalization_steps, vp[vsize - 1]);
|
|
|
|
/* Normalize the divisor and the dividend. */
|
|
if (normalization_steps != 0)
|
|
{
|
|
mp_ptr tmp;
|
|
mp_limb_t dividend_high, dividend_low;
|
|
|
|
/* Shift up the divisor setting the most significant bit of
|
|
the most significant limb. Use temporary storage not to clobber
|
|
the original contents of the divisor. */
|
|
tmp = (mp_ptr) TMP_ALLOC (vsize * BYTES_PER_MP_LIMB);
|
|
mpn_lshift (tmp, vp, vsize, normalization_steps);
|
|
vp = tmp;
|
|
|
|
/* Shift up the dividend, possibly introducing a new most
|
|
significant word. */
|
|
dividend_high = (mp_limb_t) u >> (BITS_PER_MP_LIMB - normalization_steps);
|
|
dividend_low = (mp_limb_t) u << normalization_steps;
|
|
|
|
tp[tsize - 1] = dividend_low;
|
|
if (dividend_high != 0)
|
|
{
|
|
tp[tsize] = dividend_high;
|
|
tsize++;
|
|
rexp++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* The divisor is already normalized, as required.
|
|
Copy it to temporary space if it overlaps with the quotient. */
|
|
if (vp - rp <= tsize - vsize)
|
|
{
|
|
mp_ptr tmp = (mp_ptr) TMP_ALLOC (vsize * BYTES_PER_MP_LIMB);
|
|
MPN_COPY (tmp, vp, vsize);
|
|
vp = (mp_srcptr) tmp;
|
|
}
|
|
|
|
tp[tsize - 1] = u;
|
|
}
|
|
|
|
q_limb = mpn_divmod (rp, tp, tsize, vp, vsize);
|
|
rsize = tsize - vsize;
|
|
if (q_limb)
|
|
{
|
|
rp[rsize] = q_limb;
|
|
rsize++;
|
|
rexp++;
|
|
}
|
|
|
|
r->_mp_size = sign_quotient >= 0 ? rsize : -rsize;
|
|
r->_mp_exp = rexp;
|
|
TMP_FREE (marker);
|
|
}
|