Add Chromium-only Blender WebEngine parity work

blender-5.2.0/extern/gmp-source/mpn/generic/trialdiv.c

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+/* mpn_trialdiv -- find small factors of an mpn number using trial division.
+
+   Contributed to the GNU project by Torbjorn Granlund.
+
+   THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE.  IT IS ONLY
+   SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES.  IN FACT, IT IS ALMOST
+   GUARANTEED THAT IT WILL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
+
+Copyright 2009, 2010, 2012, 2013 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/.  */
+
+/*
+   This function finds the first (smallest) factor represented in
+   trialdivtab.h.  It does not stop the factoring effort just because it has
+   reached some sensible limit, such as the square root of the input number.
+
+   The caller can limit the factoring effort by passing NPRIMES.  The function
+   will then divide until that limit, or perhaps a few primes more.  A position
+   which only mpn_trialdiv can make sense of is returned in the WHERE
+   parameter.  It can be used for restarting the factoring effort; the first
+   call should pass 0 here.
+
+   Input:        1. A non-negative number T = {tp,tn}
+                 2. NPRIMES as described above,
+                 3. *WHERE as described above.
+   Output:       1. *WHERE updated as described above.
+                 2. Return value is non-zero if we found a factor, else zero
+                    To get the actual prime factor, compute the mod B inverse
+                    of the return value.
+*/
+
+#include "gmp-impl.h"
+
+struct gmp_primes_dtab {
+  mp_limb_t binv;
+  mp_limb_t lim;
+};
+
+struct gmp_primes_ptab {
+  mp_limb_t ppp;	/* primes, multiplied together */
+  mp_limb_t cps[7];	/* ppp values pre-computed for mpn_mod_1s_4p */
+  gmp_uint_least32_t idx:24;	/* index of  first primes in dtab */
+  gmp_uint_least32_t np :8;	/* number of primes related to this entry */
+};
+
+
+static const struct gmp_primes_dtab gmp_primes_dtab[] =
+{
+#define WANT_dtab
+#define P(p,inv,lim) {inv,lim}
+#include "trialdivtab.h"
+#undef WANT_dtab
+#undef P
+  {0,0}
+};
+
+static const struct gmp_primes_ptab gmp_primes_ptab[] =
+{
+#define WANT_ptab
+#include "trialdivtab.h"
+#undef WANT_ptab
+};
+
+#define PTAB_LINES (sizeof (gmp_primes_ptab) / sizeof (gmp_primes_ptab[0]))
+
+/* FIXME: We could optimize out one of the outer loop conditions if we
+   had a final ptab entry with a huge np field.  */
+mp_limb_t
+mpn_trialdiv (mp_srcptr tp, mp_size_t tn, mp_size_t nprimes, int *where)
+{
+  mp_limb_t ppp;
+  const mp_limb_t *cps;
+  const struct gmp_primes_dtab *dp;
+  long i, j, idx, np;
+  mp_limb_t r, q;
+
+  ASSERT (tn >= 1);
+
+  for (i = *where; i < PTAB_LINES; i++)
+    {
+      ppp = gmp_primes_ptab[i].ppp;
+      cps = gmp_primes_ptab[i].cps;
+
+      r = mpn_mod_1s_4p (tp, tn, ppp << cps[1], cps);
+
+      idx = gmp_primes_ptab[i].idx;
+      np = gmp_primes_ptab[i].np;
+
+      /* Check divisibility by individual primes.  */
+      dp = &gmp_primes_dtab[idx] + np;
+      for (j = -np; j < 0; j++)
+	{
+	  q = r * dp[j].binv;
+	  if (q <= dp[j].lim)
+	    {
+	      *where = i;
+	      return dp[j].binv;
+	    }
+	}
+
+      nprimes -= np;
+      if (nprimes <= 0)
+	return 0;
+    }
+  return 0;
+}