45 lines
1.5 KiB
C
45 lines
1.5 KiB
C
|
/*
|
||
|
Copyright 2009 Jason Moxham
|
||
|
|
||
|
This file is part of the MPIR Library.
|
||
|
|
||
|
The MPIR 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 2.1 of the License, or (at
|
||
|
your option) any later version.
|
||
|
|
||
|
The MPIR 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 MPIR Library; see the file COPYING.LIB. If not, write
|
||
|
to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
|
||
|
Boston, MA 02110-1301, USA.
|
||
|
*/
|
||
|
|
||
|
#include "mpir.h"
|
||
|
#include "gmp-impl.h"
|
||
|
#include "longlong.h"
|
||
|
|
||
|
mp_limb_t mpn_divrem_hensel_rsh_qr_1(mp_ptr qp,mp_srcptr xp,mp_size_t n,mp_limb_t d,int s)
|
||
|
{mp_size_t j;mp_limb_t c,h,q,dummy,h1,t,m;
|
||
|
|
||
|
ASSERT(n>0);ASSERT(d%2==1);ASSERT_MPN(xp,n);ASSERT(MPN_SAME_OR_SEPARATE_P(qp,xp,n));
|
||
|
ASSERT(s>=0);modlimb_invert(m,d);//should we allow s=0 ??
|
||
|
c=0;h=0;t=0;
|
||
|
for(j=0;j<=n-2;j++)
|
||
|
{h1=(xp[j]>>s)|(xp[j+1]<<(GMP_LIMB_BITS-1-s)<<1);
|
||
|
t=h+c;if(t>h1){h1=h1-t;c=1;}else{h1=h1-t;c=0;}
|
||
|
q=h1*m;
|
||
|
qp[j]=q;
|
||
|
umul_ppmm(h,dummy,q,d);
|
||
|
ASSERT(dummy==h1);}
|
||
|
h1=xp[n-1]>>s;
|
||
|
t=h+c;if(t>h1){h1=h1-t;c=1;}else{h1=h1-t;c=0;}
|
||
|
q=h1*m;qp[n-1]=q;
|
||
|
umul_ppmm(h,dummy,q,d);
|
||
|
ASSERT(dummy==h1);
|
||
|
return h+c;}
|