mirror of
git://sourceware.org/git/glibc.git
synced 2025-03-06 20:58:33 +01:00
ecb1e7220d
According to ISO C23 (7.6.4.4), fesetexcept is supposed to set floating-point exception flags without raising a trap (unlike feraiseexcept, which is supposed to raise a trap if feenableexcept was called with the appropriate argument). This is a side-effect of how we implement the GNU extension feenableexcept, where feenableexcept/fesetenv/fesetmode/feupdateenv might issue prctl (PR_SET_FPEXC, PR_FP_EXC_PRECISE) depending of the argument. And on PR_FP_EXC_PRECISE, setting a floating-point exception flag triggers a trap. To make the both functions follow the C23, fesetexcept and fesetexceptflag now fail if the argument may trigger a trap. The math tests now check for an value different than 0, instead of bail out as unsupported for EXCEPTION_SET_FORCES_TRAP. Checked on powerpc64le-linux-gnu. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
47 lines
1.5 KiB
C
47 lines
1.5 KiB
C
/* Set given exception flags. PowerPC version.
|
|
Copyright (C) 2016-2023 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/>. */
|
|
|
|
#include <fenv_libc.h>
|
|
|
|
int
|
|
fesetexcept (int excepts)
|
|
{
|
|
fenv_union_t u, n;
|
|
|
|
u.fenv = fegetenv_register ();
|
|
n.l = (u.l
|
|
| (excepts & FPSCR_STICKY_BITS)
|
|
/* Turn FE_INVALID into FE_INVALID_SOFTWARE. */
|
|
| (excepts >> ((31 - FPSCR_VX) - (31 - FPSCR_VXSOFT))
|
|
& FE_INVALID_SOFTWARE));
|
|
if (n.l != u.l)
|
|
{
|
|
if (n.l & fenv_exceptions_to_reg (excepts))
|
|
/* Setting the exception flags may trigger a trap. ISO C 23 § 7.6.4.4
|
|
does not allow it. */
|
|
return -1;
|
|
|
|
fesetenv_register (n.fenv);
|
|
|
|
/* Deal with FE_INVALID_SOFTWARE not being implemented on some chips. */
|
|
if (excepts & FE_INVALID)
|
|
feraiseexcept (FE_INVALID);
|
|
}
|
|
|
|
return 0;
|
|
}
|