glibc/sysdeps/arm/feenablxcpt.c

52 lines
1.5 KiB
C

/* Enable floating-point exceptions.
Copyright (C) 2001-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Philip Blundell <philb@gnu.org>, 2001.
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 <fenv.h>
#include <fpu_control.h>
#include <arm-features.h>
int
feenableexcept (int excepts)
{
fpu_control_t fpscr, new_fpscr, updated_fpscr;
/* Fail if a VFP unit isn't present. */
if (!ARM_HAVE_VFP)
return -1;
_FPU_GETCW (fpscr);
excepts &= FE_ALL_EXCEPT;
new_fpscr = fpscr | (excepts << FE_EXCEPT_SHIFT);
if (new_fpscr != fpscr)
{
_FPU_SETCW (new_fpscr);
/* Not all VFP architectures support trapping exceptions, so
test whether the relevant bits were set and fail if not. */
_FPU_GETCW (updated_fpscr);
if (new_fpscr & ~updated_fpscr)
return -1;
}
return (fpscr >> FE_EXCEPT_SHIFT) & FE_ALL_EXCEPT;
}