1 files changed, 35 insertions, 0 deletions
diff --git a/mpfr/i_floor_log2.c b/mpfr/i_floor_log2.c
new file mode 100644
index 000000000..a4879610e
--- /dev/null
+++ b/mpfr/i_floor_log2.c
@@ -0,0 +1,35 @@
+/* _mpfr_floor_log2 - returns floor(log(d)/log(2))
+
+Copyright (C) 1999-2002 Free Software Foundation.
+
+This file is part of the MPFR Library.
+
+The MPFR Library 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 2.1 of the License, or (at your
+option) any later version.
+
+The MPFR 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the MPFR Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "mpfr.h"
+#include "mpfr-impl.h"
+
+/* returns floor(log(d)/log(2)) */
+long
+_mpfr_floor_log2 (double d)
+{
+  union ieee_double_extract x;
+
+  x.d = d;
+  return (long) x.s.exp - 1023;
+}