Initial commit.

1 files changed, 135 insertions, 0 deletions

diff --git a/gmp-6.3.0/mpz/gcdext.c b/gmp-6.3.0/mpz/gcdext.c
new file mode 100644
index 0000000..b1f73c2
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+++ b/gmp-6.3.0/mpz/gcdext.c
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+/* mpz_gcdext(g, s, t, a, b) -- Set G to gcd(a, b), and S and T such that
+   g = as + bt.
+
+Copyright 1991, 1993-1997, 2000, 2001, 2005, 2011, 2012, 2015 Free
+Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP Library is free software; you can redistribute it and/or modify
+it under the terms of either:
+
+  * the GNU Lesser General Public License as published by the Free
+    Software Foundation; either version 3 of the License, or (at your
+    option) any later version.
+
+or
+
+  * the GNU General Public License as published by the Free Software
+    Foundation; either version 2 of the License, or (at your option) any
+    later version.
+
+or both in parallel, as here.
+
+The GNU MP Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library.  If not,
+see https://www.gnu.org/licenses/.  */
+
+#include <stdio.h> /* for NULL */
+#include "gmp-impl.h"
+
+void
+mpz_gcdext (mpz_ptr g, mpz_ptr s, mpz_ptr t, mpz_srcptr a, mpz_srcptr b)
+{
+  mp_size_t asize, bsize;
+  mp_ptr tmp_ap, tmp_bp;
+  mp_size_t gsize, ssize, tmp_ssize;
+  mp_ptr gp, tmp_gp, tmp_sp;
+  TMP_DECL;
+
+  /* mpn_gcdext requires that Usize >= Vsize.  Therefore, we often
+     have to swap U and V.  The computed cofactor will be the
+     "smallest" one, which is faster to produce.  The wanted one will
+     be computed here; this is needed anyway when both are requested.  */
+
+  asize = ABSIZ (a);
+  bsize = ABSIZ (b);
+
+  ASSERT (s != NULL);
+
+  if (asize < bsize)
+    {
+      MPZ_SRCPTR_SWAP (a, b);
+      MP_SIZE_T_SWAP (asize, bsize);
+      MPZ_PTR_SWAP (s, t);
+    }
+
+  if (bsize == 0)
+    {
+      /* g = |a|, s = sgn(a), t = 0. */
+      ssize = SIZ (a) >= 0 ? (asize != 0) : -1;
+
+      if (g != NULL)
+	{
+	  /* If g == a, then ALLOC(g) == ALLOC(a) >= asize, i.e.
+	     the next MPZ_NEWALLOC returns the old PTR(a) .*/
+	  gp = MPZ_NEWALLOC (g, asize);
+	  MPN_COPY (gp, PTR (a), asize);
+	  SIZ (g) = asize;
+	}
+      if (t != NULL)
+	SIZ (t) = 0;
+      if (s != NULL)
+	{
+	  SIZ (s) = ssize;
+	  MPZ_NEWALLOC (s, 1)[0] = 1;
+	}
+      return;
+    }
+
+  TMP_MARK;
+
+  TMP_ALLOC_LIMBS_2 (tmp_gp, bsize, tmp_sp, asize + bsize + bsize + 1);
+  tmp_bp = tmp_sp + bsize + 1;
+  tmp_ap = tmp_bp + bsize;
+  MPN_COPY (tmp_ap, PTR (a), asize);
+  MPN_COPY (tmp_bp, PTR (b), bsize);
+
+  gsize = mpn_gcdext (tmp_gp, tmp_sp, &tmp_ssize, tmp_ap, asize, tmp_bp, bsize);
+
+  ssize = ABS (tmp_ssize);
+  tmp_ssize = SIZ (a) >= 0 ? tmp_ssize : -tmp_ssize;
+
+  if (t != NULL)
+    {
+      mpz_t x;
+      mpz_t gtmp, stmp;
+
+      PTR (gtmp) = tmp_gp;
+      SIZ (gtmp) = gsize;
+
+      PTR (stmp) = tmp_sp;
+      SIZ (stmp) = tmp_ssize;
+
+      ASSERT (ssize <= bsize); /* ssize*2 + asize + 1 <= asize + bsize*2 + 1 */
+      PTR (x) = tmp_sp + ssize;
+      ALLOC (x) = ssize + asize + 1;
+
+      mpz_mul (x, stmp, a);
+      mpz_sub (x, gtmp, x);
+      mpz_divexact (t, x, b);
+    }
+
+  if (s != NULL)
+    {
+      mp_ptr sp;
+
+      sp = MPZ_NEWALLOC (s, ssize);
+      MPN_COPY (sp, tmp_sp, ssize);
+      SIZ (s) = tmp_ssize;
+    }
+
+  if (g != NULL)
+    {
+      gp = MPZ_NEWALLOC (g, gsize);
+      MPN_COPY (gp, tmp_gp, gsize);
+      SIZ (g) = gsize;
+    }
+
+  TMP_FREE;
+}