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/* mpn_div_qr_2n_pi1
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Contributed to the GNU project by Torbjorn Granlund and Niels Möller
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THIS FILE CONTAINS INTERNAL FUNCTIONS WITH MUTABLE INTERFACES. IT IS ONLY
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SAFE TO REACH THEM THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST
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GUARANTEED THAT THEY'LL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
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Copyright 1993-1996, 1999-2002, 2011 Free Software Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of either:
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* the GNU Lesser General Public License as published by the Free
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Software Foundation; either version 3 of the License, or (at your
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option) any later version.
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or
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* the GNU General Public License as published by the Free Software
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Foundation; either version 2 of the License, or (at your option) any
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later version.
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or both in parallel, as here.
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The GNU MP 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 General Public License
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for more details.
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You should have received copies of the GNU General Public License and the
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GNU Lesser General Public License along with the GNU MP Library. If not,
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see https://www.gnu.org/licenses/. */
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#include "gmp.h"
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#include "gmp-impl.h"
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#include "longlong.h"
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/* 3/2 loop, for normalized divisor */
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mp_limb_t
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mpn_div_qr_2n_pi1 (mp_ptr qp, mp_ptr rp, mp_srcptr np, mp_size_t nn,
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mp_limb_t d1, mp_limb_t d0, mp_limb_t di)
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{
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mp_limb_t qh;
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mp_size_t i;
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mp_limb_t r1, r0;
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ASSERT (nn >= 2);
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ASSERT (d1 & GMP_NUMB_HIGHBIT);
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np += nn - 2;
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r1 = np[1];
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r0 = np[0];
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qh = 0;
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if (r1 >= d1 && (r1 > d1 || r0 >= d0))
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{
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#if GMP_NAIL_BITS == 0
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sub_ddmmss (r1, r0, r1, r0, d1, d0);
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#else
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r0 = r0 - d0;
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r1 = r1 - d1 - (r0 >> GMP_LIMB_BITS - 1);
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r0 &= GMP_NUMB_MASK;
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#endif
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qh = 1;
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}
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for (i = nn - 2 - 1; i >= 0; i--)
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{
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mp_limb_t n0, q;
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n0 = np[-1];
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udiv_qr_3by2 (q, r1, r0, r1, r0, n0, d1, d0, di);
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np--;
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qp[i] = q;
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}
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rp[1] = r1;
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rp[0] = r0;
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return qh;
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}
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