1 files changed, 53 insertions, 0 deletions
diff --git a/sysdeps/generic/frexp.c b/sysdeps/generic/frexp.c
new file mode 100644
index 0000000000..b2705bdf52
--- /dev/null
+++ b/sysdeps/generic/frexp.c
@@ -0,0 +1,53 @@
+/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#include <ansidecl.h>
+#include <errno.h>
+#include <math.h>
+
+/* Break VALUE into a normalized fraction and an integral power of 2.  */
+double
+DEFUN(frexp, (value, exp), double value AND int *exp)
+{
+#ifdef	NAN
+  if (__isinf (value))
+    {
+      errno = EDOM;
+      *exp = 0;
+      return __copysign (NAN, value);
+    }
+#endif
+
+  if (__isnan (value))
+    {
+      errno = EDOM;
+      *exp = 0;
+      return value;
+    }
+
+  if (value == 0)
+    {
+      *exp = 0;
+      return value;
+    }
+
+  /* Add one to the exponent of the number,
+     so we have one digit before the binary point.  */
+  *exp = (int) __logb (value) + 1;
+  return ldexp (value, - *exp);
+}