vasilito
ff4ff35918
Red Bear OS is a full fork. All sources must be available from git clone with zero network access. Removed gitignore rules that excluded fetched source trees under recipes/*/source/, local/recipes/kde/*/source/, local/recipes/qt/*/source/, and vendor source trees. Build artifacts (target/, build/, source.tar, *.o, *.so) remain excluded. 127291 files added — kernel, relibc, base, bootloader, pkgar, all KDE/Qt frameworks, mesa, wayland, DRM drivers, and every other recipe source.
75 lines
2.0 KiB
C
75 lines
2.0 KiB
C
/* mpn_gcd_11 -- limb greatest common divisor.
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Copyright 1994, 1996, 2000, 2001, 2009, 2012, 2019 Free Software Foundation,
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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-impl.h"
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#include "longlong.h"
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mp_limb_t
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mpn_gcd_11 (mp_limb_t u, mp_limb_t v)
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{
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ASSERT (u & v & 1);
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/* In this loop, we represent the odd numbers ulimb and vlimb
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without the redundant least significant one bit. This reduction
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in size by one bit ensures that the high bit of t, below, is set
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if and only if vlimb > ulimb. */
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u >>= 1;
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v >>= 1;
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while (u != v)
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{
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mp_limb_t t;
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mp_limb_t vgtu;
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int c;
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t = u - v;
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vgtu = LIMB_HIGHBIT_TO_MASK (t);
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/* v <-- min (u, v) */
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v += (vgtu & t);
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/* u <-- |u - v| */
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u = (t ^ vgtu) - vgtu;
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count_trailing_zeros (c, t);
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/* We have c <= GMP_LIMB_BITS - 2 here, so that
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ulimb >>= (c + 1);
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would be safe. But unlike the addition c + 1, a separate
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shift by 1 is independent of c, and can be executed in
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parallel with count_trailing_zeros. */
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u = (u >> 1) >> c;
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}
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return (u << 1) + 1;
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}
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