6ec01646dc
BMakefiles and other bits will follow. Requested by: Andrey Chernov Made world by: Chuck Robey
69 lines
1.7 KiB
C
69 lines
1.7 KiB
C
/* mpz_tdiv_q_2exp -- Divide an integer by 2**CNT. Round the quotient
|
|
towards -infinity.
|
|
|
|
Copyright (C) 1991, 1993, 1994, 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"
|
|
|
|
void
|
|
#if __STDC__
|
|
mpz_tdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long int cnt)
|
|
#else
|
|
mpz_tdiv_q_2exp (w, u, cnt)
|
|
mpz_ptr w;
|
|
mpz_srcptr u;
|
|
unsigned long int cnt;
|
|
#endif
|
|
{
|
|
mp_size_t usize, wsize;
|
|
mp_size_t limb_cnt;
|
|
|
|
usize = u->_mp_size;
|
|
limb_cnt = cnt / BITS_PER_MP_LIMB;
|
|
wsize = ABS (usize) - limb_cnt;
|
|
if (wsize <= 0)
|
|
w->_mp_size = 0;
|
|
else
|
|
{
|
|
mp_ptr wp;
|
|
mp_srcptr up;
|
|
|
|
if (w->_mp_alloc < wsize)
|
|
_mpz_realloc (w, wsize);
|
|
|
|
wp = w->_mp_d;
|
|
up = u->_mp_d;
|
|
|
|
cnt %= BITS_PER_MP_LIMB;
|
|
if (cnt != 0)
|
|
{
|
|
mpn_rshift (wp, up + limb_cnt, wsize, cnt);
|
|
wsize -= wp[wsize - 1] == 0;
|
|
}
|
|
else
|
|
{
|
|
MPN_COPY_INCR (wp, up + limb_cnt, wsize);
|
|
}
|
|
|
|
w->_mp_size = usize >= 0 ? wsize : -wsize;
|
|
}
|
|
}
|