New module 'modfl'.

* lib/math.in.h (modfl): New declaration.
* lib/modfl.c: New file.
* m4/modfl.m4: New file.
* m4/math_h.m4 (gl_MATH_H): Test whether modfl is declared.
(gl_MATH_H_DEFAULTS): Initialize GNULIB_MODFL, HAVE_MODFL.
* modules/math (Makefile.am): Substitute GNULIB_MODFL, HAVE_MODFL.
* modules/modfl: New file.
* doc/posix-functions/modfl.texi: Mention the new module.

1 files changed, 43 insertions, 0 deletions

diff --git a/lib/modfl.c b/lib/modfl.c
new file mode 100644
index 0000000000..770294b392
--- /dev/null
+++ b/lib/modfl.c
@@ -0,0 +1,43 @@
+/* Get signed integer and fractional parts of a floating-point number.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <math.h>
+
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
+long double
+modfl (long double x, long double *iptr)
+{
+  double integer_part;
+  double fractional_part = modf (x, &integer_part);
+  *iptr = integer_part;
+  return fractional_part;
+}
+
+#else
+
+long double
+modfl (long double x, long double *iptr)
+{
+  long double integer_part = truncl (x);
+  *iptr = integer_part;
+  return x - integer_part;
+}
+
+#endif