1 files changed, 66 insertions, 0 deletions
diff --git a/lib/next_prime.c b/lib/next_prime.c
new file mode 100644
index 00000000..f2c921e3
--- /dev/null
+++ b/lib/next_prime.c
@@ -0,0 +1,66 @@
+/* Determine prime number.
+   Copyright (C) 2006 Red Hat, Inc.
+   This file is part of elfutils.
+   Written by Ulrich Drepper <drepper@redhat.com>, 2000.
+
+   This file 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.
+
+   elfutils 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 this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <stddef.h>
+
+
+/* Test whether CANDIDATE is a prime.  */
+static int
+is_prime (size_t candidate)
+{
+  /* No even number and none less than 10 will be passed here.  */
+  size_t divn = 3;
+  size_t sq = divn * divn;
+
+  while (sq < candidate && candidate % divn != 0)
+    {
+      size_t old_sq = sq;
+      ++divn;
+      sq += 4 * divn;
+      if (sq < old_sq)
+	return 1;
+      ++divn;
+    }
+
+  return candidate % divn != 0;
+}
+
+
+/* We need primes for the table size.  */
+size_t
+next_prime (size_t seed)
+{
+  /* Make it definitely odd.  */
+  seed |= 1;
+
+  while (!is_prime (seed))
+    seed += 2;
+
+  return seed;
+}