glibc/sysdeps/s390/fpu/fesetenv.c

58 lines
1.8 KiB
C

/* Install given floating-point environment.
Copyright (C) 2000, 2002 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 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, 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;
}
libm_hidden_def (fesetenv)