vasilito
facf0c92e0
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.
136 lines
3.3 KiB
C
136 lines
3.3 KiB
C
/* mpz_gcdext(g, s, t, a, b) -- Set G to gcd(a, b), and S and T such that
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g = as + bt.
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Copyright 1991, 1993-1997, 2000, 2001, 2005, 2011, 2012, 2015 Free
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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 <stdio.h> /* for NULL */
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#include "gmp-impl.h"
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void
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mpz_gcdext (mpz_ptr g, mpz_ptr s, mpz_ptr t, mpz_srcptr a, mpz_srcptr b)
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{
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mp_size_t asize, bsize;
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mp_ptr tmp_ap, tmp_bp;
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mp_size_t gsize, ssize, tmp_ssize;
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mp_ptr gp, tmp_gp, tmp_sp;
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TMP_DECL;
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/* mpn_gcdext requires that Usize >= Vsize. Therefore, we often
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have to swap U and V. The computed cofactor will be the
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"smallest" one, which is faster to produce. The wanted one will
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be computed here; this is needed anyway when both are requested. */
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asize = ABSIZ (a);
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bsize = ABSIZ (b);
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ASSERT (s != NULL);
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if (asize < bsize)
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{
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MPZ_SRCPTR_SWAP (a, b);
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MP_SIZE_T_SWAP (asize, bsize);
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MPZ_PTR_SWAP (s, t);
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}
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if (bsize == 0)
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{
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/* g = |a|, s = sgn(a), t = 0. */
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ssize = SIZ (a) >= 0 ? (asize != 0) : -1;
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if (g != NULL)
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{
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/* If g == a, then ALLOC(g) == ALLOC(a) >= asize, i.e.
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the next MPZ_NEWALLOC returns the old PTR(a) .*/
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gp = MPZ_NEWALLOC (g, asize);
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MPN_COPY (gp, PTR (a), asize);
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SIZ (g) = asize;
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}
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if (t != NULL)
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SIZ (t) = 0;
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if (s != NULL)
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{
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SIZ (s) = ssize;
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MPZ_NEWALLOC (s, 1)[0] = 1;
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}
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return;
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}
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TMP_MARK;
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TMP_ALLOC_LIMBS_2 (tmp_gp, bsize, tmp_sp, asize + bsize + bsize + 1);
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tmp_bp = tmp_sp + bsize + 1;
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tmp_ap = tmp_bp + bsize;
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MPN_COPY (tmp_ap, PTR (a), asize);
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MPN_COPY (tmp_bp, PTR (b), bsize);
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gsize = mpn_gcdext (tmp_gp, tmp_sp, &tmp_ssize, tmp_ap, asize, tmp_bp, bsize);
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ssize = ABS (tmp_ssize);
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tmp_ssize = SIZ (a) >= 0 ? tmp_ssize : -tmp_ssize;
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if (t != NULL)
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{
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mpz_t x;
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mpz_t gtmp, stmp;
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PTR (gtmp) = tmp_gp;
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SIZ (gtmp) = gsize;
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PTR (stmp) = tmp_sp;
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SIZ (stmp) = tmp_ssize;
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ASSERT (ssize <= bsize); /* ssize*2 + asize + 1 <= asize + bsize*2 + 1 */
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PTR (x) = tmp_sp + ssize;
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ALLOC (x) = ssize + asize + 1;
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mpz_mul (x, stmp, a);
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mpz_sub (x, gtmp, x);
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mpz_divexact (t, x, b);
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}
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if (s != NULL)
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{
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mp_ptr sp;
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sp = MPZ_NEWALLOC (s, ssize);
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MPN_COPY (sp, tmp_sp, ssize);
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SIZ (s) = tmp_ssize;
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}
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if (g != NULL)
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{
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gp = MPZ_NEWALLOC (g, gsize);
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MPN_COPY (gp, tmp_gp, gsize);
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SIZ (g) = gsize;
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}
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TMP_FREE;
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}
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