45 lines
1.5 KiB
C
45 lines
1.5 KiB
C
/*
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Copyright 2009 Jason Moxham
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This file is part of the MPIR Library.
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The MPIR Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published
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by the Free Software Foundation; either version 2.1 of the License, or (at
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your option) any later version.
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The MPIR Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the MPIR Library; see the file COPYING.LIB. If not, write
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to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA.
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*/
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#include "mpir.h"
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#include "gmp-impl.h"
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#include "longlong.h"
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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)
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{mp_size_t j;mp_limb_t c,h,q,dummy,h1,t,m;
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ASSERT(n>0);ASSERT(d%2==1);ASSERT_MPN(xp,n);ASSERT(MPN_SAME_OR_SEPARATE_P(qp,xp,n));
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ASSERT(s>=0);modlimb_invert(m,d);//should we allow s=0 ??
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c=0;h=0;t=0;
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for(j=0;j<=n-2;j++)
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{h1=(xp[j]>>s)|(xp[j+1]<<(GMP_LIMB_BITS-1-s)<<1);
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t=h+c;if(t>h1){h1=h1-t;c=1;}else{h1=h1-t;c=0;}
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q=h1*m;
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qp[j]=q;
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umul_ppmm(h,dummy,q,d);
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ASSERT(dummy==h1);}
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h1=xp[n-1]>>s;
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t=h+c;if(t>h1){h1=h1-t;c=1;}else{h1=h1-t;c=0;}
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q=h1*m;qp[n-1]=q;
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umul_ppmm(h,dummy,q,d);
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ASSERT(dummy==h1);
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return h+c;}
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