mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-14 09:01:07 +00:00
46 lines
1.8 KiB
C
46 lines
1.8 KiB
C
/* Install given floating-point environment.
|
|
Copyright (C) 1997 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Richard Henderson <rth@tamu.edu>, 1997
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#include <fenv.h>
|
|
|
|
void
|
|
fesetenv (const fenv_t *envp)
|
|
{
|
|
unsigned long 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)envp >= 0)
|
|
env = *envp;
|
|
else
|
|
env = (unsigned long)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 & ~(3UL << 58)) | (env & (3UL << 58));
|
|
__asm__ __volatile__("mt_fpcr %0" : : "f"(fpcr));
|
|
|
|
/* Reset the exception status and mask with the kernel's FP code. */
|
|
__ieee_set_fp_control(env & (FE_ALL_EXCEPT | 0x3e));
|
|
}
|