New module 'copysignl'.

* lib/math.in.h (copysignl): New declaration.
* lib/copysignl.c: New file.
* m4/copysignl.m4: New file.
* m4/math_h.m4 (gl_MATH_H): Test whether copysignl is declared.
(gl_MATH_H_DEFAULTS): Initialize GNULIB_COPYSIGNL, HAVE_COPYSIGNL.
* modules/math (Makefile.am): Substitute GNULIB_COPYSIGNL,
HAVE_COPYSIGNL.
* modules/copysignl: New file.
* tests/test-math-c++.cc: Check the declaration of copysignl.
* modules/math-c++-tests (Makefile.am): Link test-math-c++ against
$(COPYSIGNL_LIBM). Needed on IRIX 6.5 with cc.
* doc/posix-functions/copysignl.texi: Mention the new module.

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/copysignl.c b/lib/copysignl.c
new file mode 100644
index 0000000000..95947f464a
--- /dev/null
+++ b/lib/copysignl.c
@@ -0,0 +1,26 @@
+/* Copy sign into another 'long double' number.
+   Copyright (C) 2011 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>
+
+long double
+copysignl (long double x, long double y)
+{
+  return (signbit (x) != signbit (y) ? - x : x);
+}