glibc/sysdeps/s390/fpu/fesetenv.c
2000-08-21 17:06:46 +00:00

57 lines
1.8 KiB
C

/* Install given floating-point environment.
Copyright (C) 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Denis Joseph Barrow (djbarrow@de.ibm.com).
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_libc.h>
#include <fpu_control.h>
#include <stddef.h>
#include <asm/ptrace.h>
#include <sys/ptrace.h>
#include <unistd.h>
int
fesetenv (const fenv_t *envp)
{
fenv_t env;
if (envp == FE_DFL_ENV)
{
env.fpc = _FPU_DEFAULT;
env.ieee_instruction_pointer = 0;
}
else if (envp == FE_NOMASK_ENV)
{
env.fpc = FPC_EXCEPTION_MASK;
env.ieee_instruction_pointer = 0;
}
else
env = (*envp);
/* The S/390 IEEE fpu doesn't have a register for the ieee
instruction pointer. The operating system is required to keep an
instruction pointer on a per process base. We read and write this
value with the ptrace interface. */
_FPU_SETCW (env.fpc);
ptrace (PTRACE_POKEUSER, getpid (), PT_IEEE_IP,
env.ieee_instruction_pointer);
/* Success. */
return 0;
}