1 files changed, 33 insertions, 0 deletions
diff --git a/mpc/src/uceil_log2.c b/mpc/src/uceil_log2.c
new file mode 100644
index 0000000000..df946128d8
--- /dev/null
+++ b/mpc/src/uceil_log2.c
@@ -0,0 +1,33 @@
+/* mpc_ceil_log2 - returns ceil(log(d)/log(2))
+
+Copyright (C) 2004, 2009, 2010 INRIA
+
+This file is part of GNU MPC.
+
+GNU MPC is free software; you can redistribute it and/or modify it under
+the terms of 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.
+
+GNU MPC 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 Lesser General Public License for
+more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program. If not, see http://www.gnu.org/licenses/ .
+*/
+
+#include "mpc-impl.h"
+
+/* returns ceil(log(d)/log(2)) if d > 0 */
+/* Don't use count_leading_zeros since it is in longlong.h */
+mpfr_prec_t
+mpc_ceil_log2 (mpfr_prec_t d)
+{
+  mpfr_prec_t exp;
+
+  for (exp = 0; d > 1; d = (d + 1) / 2)
+    exp++;
+  return exp;
+}