glibc/math/w_scalblnf.c
Joseph Myers 9946e7a949 Fix ldexp, scalbn, scalbln for sNaN input (bug 20225).
The wrapper implementations of ldexp / scalbn / scalbln
(architecture-independent), and their float / long double variants,
return sNaN for sNaN input.  This patch fixes them to add relevant
arguments to themselves so that qNaN is returned in this case.

Tested for x86_64 and x86.

	[BZ #20225]
	* math/s_ldexp.c (__ldexp): Add non-finite or zero argument to
	itself.
	* math/s_ldexpf.c (__ldexpf): Likewise.
	* math/s_ldexpl.c (__ldexpl): Likewise.
	* math/w_scalbln.c (__w_scalbln): Likewise.
	* math/w_scalblnf.c (__w_scalblnf): Likewise.
	* math/w_scalblnl.c (__w_scalblnl): Likewise.
	* math/libm-test.inc (scalbn_test_data): Add sNaN tests.
	(scalbln_test_data): Likewise.
2016-06-08 21:32:57 +00:00

37 lines
1.1 KiB
C

/* Wrapper for __scalblnf handles setting errno.
Copyright (C) 2014-2016 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 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 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <math.h>
#include <math_private.h>
float
__w_scalblnf (float x, long int n)
{
if (!isfinite (x) || x == 0.0f)
return x + x;
x = __scalblnf (x, n);
if (!isfinite (x) || x == 0.0f)
__set_errno (ERANGE);
return x;
}
weak_alias (__w_scalblnf, scalblnf)