55 lines
1.6 KiB
C
55 lines
1.6 KiB
C
/* mpn_preinv_mod_1 (up, un, d, dinv) -- Divide (UP,,UN) by the normalized D.
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DINV should be 2^(2*GMP_LIMB_BITS) / D - 2^GMP_LIMB_BITS.
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Return the single-limb remainder.
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Copyright 1991, 1993, 1994, 2000, 2001, 2002, 2004, 2005 Free Software
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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 it
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under the terms of the GNU Lesser General Public License as published by the
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Free Software Foundation; either version 2.1 of the License, or (at your
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option) any later version.
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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 or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
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for more details.
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You should have received a copy of the GNU Lesser General Public License along
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with the GNU MP Library; see the file COPYING.LIB. If not, write to the Free
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Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
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USA. */
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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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/* This function used to be documented, but is now considered obsolete. It
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continues to exist for binary compatibility, even when not required
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internally. */
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mp_limb_t
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mpn_preinv_mod_1 (mp_srcptr up, mp_size_t un, mp_limb_t d, mp_limb_t dinv)
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{
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mp_size_t i;
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mp_limb_t n0, r;
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mp_limb_t dummy;
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ASSERT (un >= 1);
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ASSERT (d & GMP_LIMB_HIGHBIT);
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r = up[un - 1];
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if (r >= d)
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r -= d;
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for (i = un - 2; i >= 0; i--)
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{
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n0 = up[i];
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udiv_qrnnd_preinv (dummy, r, r, n0, d, dinv);
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}
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return r;
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}
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