glibc/sysdeps/x86/fpu/s_nearestint_387_template.c
Adhemerval Zanella 637bfc392f math: x86 ceill traps when FE_INEXACT is enabled (BZ 31600)
The implementations of ceil functions using x87 floating point (i386 and
x86_64 long double only) traps when FE_INEXACT is enabled.  Although
this is a GNU extension outside the scope of the C standard, other
architectures that also support traps do not show this behavior.

The fix moves the implementation to a common one that holds any
exceptions with a 'fnclex' (libc_feholdexcept_setround_387).

Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2024-04-04 14:29:28 -03:00

37 lines
1.2 KiB
C

/* Nearest integet template for x86.
Copyright (C) 2024 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
<https://www.gnu.org/licenses/>. */
#define NO_MATH_REDIRECT
#include <math.h>
#include <fenv_private.h>
TYPE
FUNC (TYPE x)
{
fenv_t fenv;
TYPE r;
libc_feholdexcept_setround_387 (&fenv, FE_OPTION);
asm volatile ("frndint" : "=t" (r) : "0" (x));
/* Preserve "invalid" exceptions from sNaN input. */
fenv.__status_word |= libc_fetestexcept_387 (FE_INVALID);
libc_fesetenv_387 (&fenv);
return r;
}