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.
505 lines
16 KiB
C
505 lines
16 KiB
C
/* hgcd2-div.h
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THE FUNCTIONS IN THIS FILE ARE INTERNAL 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 1996, 1998, 2000-2004, 2008, 2012, 2019, 2020 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
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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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#ifndef HGCD2_DIV1_METHOD
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#define HGCD2_DIV1_METHOD 3
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#endif
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#ifndef HGCD2_DIV2_METHOD
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#define HGCD2_DIV2_METHOD 2
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#endif
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#if HAVE_NATIVE_mpn_div_11
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#define div1 mpn_div_11
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/* Single-limb division optimized for small quotients.
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Returned value holds d0 = r, d1 = q. */
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mp_double_limb_t div1 (mp_limb_t, mp_limb_t);
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#elif HGCD2_DIV1_METHOD == 1
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static inline mp_double_limb_t
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div1 (mp_limb_t n0, mp_limb_t d0)
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{
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mp_double_limb_t res;
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res.d1 = n0 / d0;
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res.d0 = n0 - res.d1 * d0;
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return res;
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}
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#elif HGCD2_DIV1_METHOD == 2
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static mp_double_limb_t
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div1 (mp_limb_t n0, mp_limb_t d0)
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{
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mp_double_limb_t res;
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int ncnt, dcnt, cnt;
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mp_limb_t q;
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mp_limb_t mask;
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ASSERT (n0 >= d0);
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count_leading_zeros (ncnt, n0);
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count_leading_zeros (dcnt, d0);
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cnt = dcnt - ncnt;
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d0 <<= cnt;
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q = -(mp_limb_t) (n0 >= d0);
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n0 -= d0 & q;
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d0 >>= 1;
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q = -q;
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while (--cnt >= 0)
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{
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mask = -(mp_limb_t) (n0 >= d0);
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n0 -= d0 & mask;
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d0 >>= 1;
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q = (q << 1) - mask;
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}
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res.d0 = n0;
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res.d1 = q;
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return res;
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}
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#elif HGCD2_DIV1_METHOD == 3
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static inline mp_double_limb_t
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div1 (mp_limb_t n0, mp_limb_t d0)
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{
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mp_double_limb_t res;
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if (UNLIKELY ((d0 >> (GMP_LIMB_BITS - 3)) != 0)
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|| UNLIKELY (n0 >= (d0 << 3)))
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{
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res.d1 = n0 / d0;
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res.d0 = n0 - res.d1 * d0;
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}
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else
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{
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mp_limb_t q, mask;
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d0 <<= 2;
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mask = -(mp_limb_t) (n0 >= d0);
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n0 -= d0 & mask;
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q = 4 & mask;
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d0 >>= 1;
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mask = -(mp_limb_t) (n0 >= d0);
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n0 -= d0 & mask;
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q += 2 & mask;
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d0 >>= 1;
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mask = -(mp_limb_t) (n0 >= d0);
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n0 -= d0 & mask;
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q -= mask;
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res.d0 = n0;
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res.d1 = q;
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}
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return res;
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}
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#elif HGCD2_DIV1_METHOD == 4
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/* Table quotients. We extract the NBITS most significant bits of the
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numerator limb, and the corresponding bits from the divisor limb, and use
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these to form an index into the table. This method is probably only useful
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for short pipelines with slow multiplication.
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Possible improvements:
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* Perhaps extract the highest NBITS of the divisor instead of the same bits
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as from the numerator. That would require another count_leading_zeros,
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and a post-multiply shift of the quotient.
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* Compress tables? Their values are tiny, and there are lots of zero
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entries (which are never used).
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* Round the table entries more cleverly?
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*/
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#ifndef NBITS
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#define NBITS 5
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#endif
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#if NBITS == 5
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/* This needs full division about 13.2% of the time. */
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static const unsigned char tab[512] = {
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17, 9, 5,4,3,2,2,2,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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18, 9, 6,4,3,2,2,2,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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19,10, 6,4,3,3,2,2,2,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,
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20,10, 6,5,3,3,2,2,2,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,
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21,11, 7,5,4,3,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,
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22,11, 7,5,4,3,3,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,
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23,12, 7,5,4,3,3,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,
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24,12, 8,6,4,3,3,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,
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25,13, 8,6,5,4,3,3,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,
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26,13, 8,6,5,4,3,3,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
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27,14, 9,6,5,4,3,3,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
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28,14, 9,7,5,4,3,3,3,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
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29,15,10,7,5,4,4,3,3,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,
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30,15,10,7,6,5,4,3,3,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,
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31,16,10,7,6,5,4,3,3,3,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,
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32,16,11,8,6,5,4,3,3,3,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
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};
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#elif NBITS == 6
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/* This needs full division about 9.8% of the time. */
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static const unsigned char tab[2048] = {
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33,17,11, 8, 6, 5,4,4,3,3,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 0, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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34,17,11, 8, 6, 5,4,4,3,3,3,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 0, 0, 0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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35,18,12, 9, 7, 5,5,4,3,3,3,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 0, 0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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36,18,12, 9, 7, 6,5,4,3,3,3,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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37,19,13, 9, 7, 6,5,4,4,3,3,3,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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38,19,13, 9, 7, 6,5,4,4,3,3,3,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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39,20,13,10, 7, 6,5,4,4,3,3,3,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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40,20,14,10, 8, 6,5,5,4,3,3,3,3,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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41,21,14,10, 8, 6,5,5,4,4,3,3,3,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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42,21,14,10, 8, 7,6,5,4,4,3,3,3,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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43,22,15,11, 8, 7,6,5,4,4,3,3,3,3,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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44,22,15,11, 9, 7,6,5,4,4,3,3,3,3,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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45,23,15,11, 9, 7,6,5,5,4,4,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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46,23,16,11, 9, 7,6,5,5,4,4,3,3,3,3,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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47,24,16,12, 9, 7,6,5,5,4,4,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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48,24,16,12, 9, 8,6,6,5,4,4,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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49,25,17,12,10, 8,7,6,5,4,4,4,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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50,25,17,13,10, 8,7,6,5,5,4,4,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
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51,26,18,13,10, 8,7,6,5,5,4,4,3,3,3,3,2,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,
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52,26,18,13,10, 8,7,6,5,5,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,
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53,27,18,13,10, 9,7,6,5,5,4,4,4,3,3,3,3,2,2,2,2,2,2,2,2,2,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,
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54,27,19,14,11, 9,7,6,6,5,4,4,4,3,3,3,3,2,2,2,2,2,2,2,2,2,1,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,
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55,28,19,14,11, 9,7,6,6,5,5,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,
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56,28,19,14,11, 9,8,7,6,5,5,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,1,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,
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57,29,20,14,11, 9,8,7,6,5,5,4,4,4,3,3,3,3,2,2,2,2,2,2,2,2,2,2,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,
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58,29,20,15,11, 9,8,7,6,5,5,4,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,1,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
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59,30,20,15,12,10,8,7,6,5,5,4,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
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60,30,21,15,12,10,8,7,6,6,5,5,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,1,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
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61,31,21,15,12,10,8,7,6,6,5,5,4,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,
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62,31,22,16,12,10,9,7,6,6,5,5,4,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,1,1,
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1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,
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|
63,32,22,16,13,10,9,7,7,6,5,5,4,4,4,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,2,1,
|
|
1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,
|
|
64,32,22,16,13,10,9,8,7,6,5,5,4,4,4,3,3,3,3,3,3,2,2,2,2,2,2,2,2,2,2,1,
|
|
1, 1, 1, 1, 1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
|
|
};
|
|
#else
|
|
#error No table for provided NBITS
|
|
#endif
|
|
|
|
/* Doing tabp with a #define makes compiler warnings about pointing outside an
|
|
object go away. We used to define this as a variable. It is not clear if
|
|
e.g. (vector[100] - 10) + 10 is well- defined as per the C standard;
|
|
(vector[100] + 10) - 10 surely is and there is no sequence point so the
|
|
expressions should be equivalent. To make this safe, we might want to
|
|
define tabp as a macro with the index as an argument. Depending on the
|
|
platform, relocs might allow for assembly-time or linker-time resolution to
|
|
take place. */
|
|
#define tabp (tab - (1 << (NBITS - 1) << NBITS))
|
|
|
|
static inline mp_double_limb_t
|
|
div1 (mp_limb_t n0, mp_limb_t d0)
|
|
{
|
|
int ncnt;
|
|
size_t nbi, dbi;
|
|
mp_limb_t q0;
|
|
mp_limb_t r0;
|
|
mp_limb_t mask;
|
|
mp_double_limb_t res;
|
|
|
|
ASSERT (n0 >= d0); /* Actually only msb position is critical. */
|
|
|
|
count_leading_zeros (ncnt, n0);
|
|
nbi = n0 << ncnt >> (GMP_LIMB_BITS - NBITS);
|
|
dbi = d0 << ncnt >> (GMP_LIMB_BITS - NBITS);
|
|
|
|
q0 = tabp[(nbi << NBITS) + dbi];
|
|
r0 = n0 - q0 * d0;
|
|
mask = -(mp_limb_t) (r0 >= d0);
|
|
q0 -= mask;
|
|
r0 -= d0 & mask;
|
|
|
|
if (UNLIKELY (r0 >= d0))
|
|
{
|
|
q0 = n0 / d0;
|
|
r0 = n0 - q0 * d0;
|
|
}
|
|
|
|
res.d1 = q0;
|
|
res.d0 = r0;
|
|
return res;
|
|
}
|
|
|
|
#elif HGCD2_DIV1_METHOD == 5
|
|
|
|
/* Table inverses of divisors. We don't bother with suppressing the msb from
|
|
the tables. We index with the NBITS most significant divisor bits,
|
|
including the always-set highest bit, but use addressing trickery via tabp
|
|
to suppress it.
|
|
|
|
Possible improvements:
|
|
|
|
* Do first multiply using 32-bit operations on 64-bit computers. At least
|
|
on most Arm64 cores, that uses 3 times less resources. It also saves on
|
|
many x86-64 processors.
|
|
*/
|
|
|
|
#ifndef NBITS
|
|
#define NBITS 7
|
|
#endif
|
|
|
|
#if NBITS == 5
|
|
/* This needs full division about 1.63% of the time. */
|
|
static const unsigned char tab[16] = {
|
|
63, 59, 55, 52, 50, 47, 45, 43, 41, 39, 38, 36, 35, 34, 33, 32
|
|
};
|
|
#elif NBITS == 6
|
|
/* This needs full division about 0.93% of the time. */
|
|
static const unsigned char tab[32] = {
|
|
127,123,119,116,112,109,106,104,101, 98, 96, 94, 92, 90, 88, 86,
|
|
84, 82, 80, 79, 77, 76, 74, 73, 72, 70, 69, 68, 67, 66, 65, 64
|
|
};
|
|
#elif NBITS == 7
|
|
/* This needs full division about 0.49% of the time. */
|
|
static const unsigned char tab[64] = {
|
|
255,251,247,243,239,236,233,229,226,223,220,217,214,211,209,206,
|
|
203,201,198,196,194,191,189,187,185,183,181,179,177,175,173,171,
|
|
169,167,166,164,162,161,159,158,156,155,153,152,150,149,147,146,
|
|
145,143,142,141,140,139,137,136,135,134,133,132,131,130,129,128
|
|
};
|
|
#elif NBITS == 8
|
|
/* This needs full division about 0.26% of the time. */
|
|
static const unsigned short tab[128] = {
|
|
511,507,503,499,495,491,488,484,480,477,473,470,467,463,460,457,
|
|
454,450,447,444,441,438,435,433,430,427,424,421,419,416,413,411,
|
|
408,406,403,401,398,396,393,391,389,386,384,382,380,377,375,373,
|
|
371,369,367,365,363,361,359,357,355,353,351,349,347,345,343,342,
|
|
340,338,336,335,333,331,329,328,326,325,323,321,320,318,317,315,
|
|
314,312,311,309,308,306,305,303,302,301,299,298,296,295,294,292,
|
|
291,290,288,287,286,285,283,282,281,280,279,277,276,275,274,273,
|
|
272,270,269,268,267,266,265,264,263,262,261,260,259,258,257,256
|
|
};
|
|
#else
|
|
#error No table for provided NBITS
|
|
#endif
|
|
|
|
/* Doing tabp with a #define makes compiler warnings about pointing outside an
|
|
object go away. We used to define this as a variable. It is not clear if
|
|
e.g. (vector[100] - 10) + 10 is well- defined as per the C standard;
|
|
(vector[100] + 10) - 10 surely is and there is no sequence point so the
|
|
expressions should be equivalent. To make this safe, we might want to
|
|
define tabp as a macro with the index as an argument. Depending on the
|
|
platform, relocs might allow for assembly-time or linker-time resolution to
|
|
take place. */
|
|
#define tabp (tab - (1 << (NBITS - 1)))
|
|
|
|
static inline mp_double_limb_t
|
|
div1 (mp_limb_t n0, mp_limb_t d0)
|
|
{
|
|
int ncnt, dcnt;
|
|
size_t dbi;
|
|
mp_limb_t inv;
|
|
mp_limb_t q0;
|
|
mp_limb_t r0;
|
|
mp_limb_t mask;
|
|
mp_double_limb_t res;
|
|
|
|
count_leading_zeros (ncnt, n0);
|
|
count_leading_zeros (dcnt, d0);
|
|
|
|
dbi = d0 << dcnt >> (GMP_LIMB_BITS - NBITS);
|
|
inv = tabp[dbi];
|
|
q0 = ((n0 << ncnt) >> (NBITS + 1)) * inv >> (GMP_LIMB_BITS - 1 + ncnt - dcnt);
|
|
r0 = n0 - q0 * d0;
|
|
mask = -(mp_limb_t) (r0 >= d0);
|
|
q0 -= mask;
|
|
r0 -= d0 & mask;
|
|
|
|
if (UNLIKELY (r0 >= d0))
|
|
{
|
|
q0 = n0 / d0;
|
|
r0 = n0 - q0 * d0;
|
|
}
|
|
|
|
res.d1 = q0;
|
|
res.d0 = r0;
|
|
return res;
|
|
}
|
|
|
|
#else
|
|
#error Unknown HGCD2_DIV1_METHOD
|
|
#endif
|
|
|
|
#if HAVE_NATIVE_mpn_div_22
|
|
|
|
#define div2 mpn_div_22
|
|
/* Two-limb division optimized for small quotients. */
|
|
mp_limb_t div2 (mp_ptr, mp_limb_t, mp_limb_t, mp_limb_t, mp_limb_t);
|
|
|
|
#elif HGCD2_DIV2_METHOD == 1
|
|
|
|
static mp_limb_t
|
|
div2 (mp_ptr rp,
|
|
mp_limb_t n1, mp_limb_t n0,
|
|
mp_limb_t d1, mp_limb_t d0)
|
|
{
|
|
mp_double_limb_t rq = div1 (n1, d1);
|
|
if (UNLIKELY (rq.d1 > d1))
|
|
{
|
|
mp_limb_t n2, q, t1, t0;
|
|
int c;
|
|
|
|
/* Normalize */
|
|
count_leading_zeros (c, d1);
|
|
ASSERT (c > 0);
|
|
|
|
n2 = n1 >> (GMP_LIMB_BITS - c);
|
|
n1 = (n1 << c) | (n0 >> (GMP_LIMB_BITS - c));
|
|
n0 <<= c;
|
|
d1 = (d1 << c) | (d0 >> (GMP_LIMB_BITS - c));
|
|
d0 <<= c;
|
|
|
|
udiv_qrnnd (q, n1, n2, n1, d1);
|
|
umul_ppmm (t1, t0, q, d0);
|
|
if (t1 > n1 || (t1 == n1 && t0 > n0))
|
|
{
|
|
ASSERT (q > 0);
|
|
q--;
|
|
sub_ddmmss (t1, t0, t1, t0, d1, d0);
|
|
}
|
|
sub_ddmmss (n1, n0, n1, n0, t1, t0);
|
|
|
|
/* Undo normalization */
|
|
rp[0] = (n0 >> c) | (n1 << (GMP_LIMB_BITS - c));
|
|
rp[1] = n1 >> c;
|
|
|
|
return q;
|
|
}
|
|
else
|
|
{
|
|
mp_limb_t q, t1, t0;
|
|
n1 = rq.d0;
|
|
q = rq.d1;
|
|
umul_ppmm (t1, t0, q, d0);
|
|
if (UNLIKELY (t1 >= n1) && (t1 > n1 || t0 > n0))
|
|
{
|
|
ASSERT (q > 0);
|
|
q--;
|
|
sub_ddmmss (t1, t0, t1, t0, d1, d0);
|
|
}
|
|
sub_ddmmss (rp[1], rp[0], n1, n0, t1, t0);
|
|
return q;
|
|
}
|
|
}
|
|
|
|
#elif HGCD2_DIV2_METHOD == 2
|
|
|
|
/* Bit-wise div2. Relies on fast count_leading_zeros. */
|
|
static mp_limb_t
|
|
div2 (mp_ptr rp,
|
|
mp_limb_t n1, mp_limb_t n0,
|
|
mp_limb_t d1, mp_limb_t d0)
|
|
{
|
|
mp_limb_t q = 0;
|
|
int ncnt;
|
|
int dcnt;
|
|
|
|
count_leading_zeros (ncnt, n1);
|
|
count_leading_zeros (dcnt, d1);
|
|
dcnt -= ncnt;
|
|
|
|
d1 = (d1 << dcnt) + (d0 >> 1 >> (GMP_LIMB_BITS - 1 - dcnt));
|
|
d0 <<= dcnt;
|
|
|
|
do
|
|
{
|
|
mp_limb_t mask;
|
|
q <<= 1;
|
|
if (UNLIKELY (n1 == d1))
|
|
mask = -(n0 >= d0);
|
|
else
|
|
mask = -(n1 > d1);
|
|
|
|
q -= mask;
|
|
|
|
sub_ddmmss (n1, n0, n1, n0, mask & d1, mask & d0);
|
|
|
|
d0 = (d1 << (GMP_LIMB_BITS - 1)) | (d0 >> 1);
|
|
d1 = d1 >> 1;
|
|
}
|
|
while (dcnt--);
|
|
|
|
rp[0] = n0;
|
|
rp[1] = n1;
|
|
|
|
return q;
|
|
}
|
|
#else
|
|
#error Unknown HGCD2_DIV2_METHOD
|
|
#endif
|