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/* Raise given exceptions.
Copyright (C) 1997, 1999, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by David Huggins-Daines <dhd@debian.org>
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>
#include <float.h>
#include <math.h>
int
feraiseexcept (int excepts)
{
/* Raise exceptions represented by EXCEPTS. But we must raise only one
signal at a time. It is important that if the overflow/underflow
exception and the divide by zero exception are given at the same
time, the overflow/underflow exception follows the divide by zero
exception. */
/* We do these bits in assembly to be certain GCC doesn't optimize
away something important, and so we can force delayed traps to
occur. */
/* FIXME: These all need verification! */
/* First: invalid exception. */
if (excepts & FE_INVALID)
{
/* One example of a invalid operation is 0 * Infinity. */
double d = HUGE_VAL;
__asm__ __volatile__ ("fmpy,dbl %1,%%fr0,%0\n\t"
/* FIXME: is this a proper trap barrier? */
"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d));
}
/* Next: division by zero. */
if (excepts & FE_DIVBYZERO)
{
double d = 1.0;
__asm__ __volatile__ ("fdiv,dbl %1,%%fr0,%0\n\t"
"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d));
}
/* Next: overflow. */
/* FIXME: Compare with IA-64 - do we have the same problem? */
if (excepts & FE_OVERFLOW)
{
double d = DBL_MAX;
__asm__ __volatile__ ("fmpy,dbl %1,%1,%0\n\t"
"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d));
}
/* Next: underflow. */
if (excepts & FE_UNDERFLOW)
{
double d = DBL_MIN;
double e = 69.69;
__asm__ __volatile__ ("fdiv,dbl %1,%2,%0\n\t"
"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d), "f" (e));
}
/* Last: inexact. */
if (excepts & FE_INEXACT)
{
double d = 1.0;
double e = M_PI;
__asm__ __volatile__ ("fdiv,dbl %1,%2,%0\n\t"
"fcpy,dbl %%fr0,%%fr0" : "=f" (d) : "0" (d), "f" (e));
}
/* Success. */
return 0;
}
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