glibc/sysdeps/alpha/fpu/fesetenv.c

57 lines
2.0 KiB
C

/* Install given floating-point environment.
Copyright (C) 1997-2024 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/>. */
#include <fenv_libc.h>
int
__fesetenv (const fenv_t *envp)
{
unsigned long int fpcr;
fenv_t env;
/* Magic encoding of default values: high bit set (never possible for a
user-space address) is not indirect. And we don't even have to get
rid of it since we mask things around just below. */
if ((long int) envp >= 0)
env = *envp;
else
env = (unsigned long int) envp;
/* Reset the rounding mode with the hardware fpcr. Note that the following
system call is an implied trap barrier for our modification. */
__asm__ __volatile__ ("excb; mf_fpcr %0" : "=f" (fpcr));
fpcr = (fpcr & ~FPCR_ROUND_MASK) | (env & FPCR_ROUND_MASK);
__asm__ __volatile__ ("mt_fpcr %0" : : "f" (fpcr));
/* Reset the exception status and mask with the kernel's FP code. */
__ieee_set_fp_control (env & SWCR_ALL_MASK);
/* Success. */
return 0;
}
#include <shlib-compat.h>
#if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
strong_alias (__fesetenv, __old_fesetenv)
compat_symbol (libm, __old_fesetenv, fesetenv, GLIBC_2_1);
#endif
libm_hidden_def (__fesetenv)
libm_hidden_ver (__fesetenv, fesetenv)
versioned_symbol (libm, __fesetenv, fesetenv, GLIBC_2_2);