glibc/sysdeps/alpha/fpu/s_rintf.c
Aurelien Jarno cb7f9d63b9 alpha: fix rint on sNaN input
The alpha version of rint wrongly return sNaN for sNaN input. Fix that
by checking for NaN and by returning the input value added with itself
in that case.

Changelog:
	* sysdeps/alpha/fpu/s_rint.c (__rint): Add argument with itself
	when it is a NaN.
	* sysdeps/alpha/fpu/s_rintf.c (__rintf): Likewise.
2016-08-02 09:18:59 +02:00

51 lines
1.5 KiB
C

/* Copyright (C) 2000-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson.
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 <math.h>
float
__rintf (float x)
{
if (isnanf (x))
return x + x;
if (isless (fabsf (x), 16777216.0f)) /* 1 << FLT_MANT_DIG */
{
/* Note that Alpha S_Floating is stored in registers in a
restricted T_Floating format, so we don't even need to
convert back to S_Floating in the end. The initial
conversion to T_Floating is needed to handle denormals. */
float tmp1, tmp2, new_x;
__asm ("cvtst/s %3,%2\n\t"
"cvttq/svid %2,%1\n\t"
"cvtqt/d %1,%0\n\t"
: "=f"(new_x), "=&f"(tmp1), "=&f"(tmp2)
: "f"(x));
/* rint(-0.1) == -0, and in general we'll always have the same
sign as our input. */
x = copysignf(new_x, x);
}
return x;
}
weak_alias (__rintf, rintf)