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/* Raise given exceptions.
Copyright (C) 1997, 1999, 2000, 2002 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 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
<http://www.gnu.org/licenses/>. */
#include <fenv.h>
#include <float.h>
#include <math.h>
/* Please see section 10,
page 10-5 "Delayed Trapping" in the PA-RISC 2.0 Architecture manual */
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. */
/* We use "fldd 0(%%sr0,%%sp),%0" to flush the delayed exception */
/* First: Invalid exception. */
if (excepts & FE_INVALID)
{
/* One example of a invalid operation is 0 * Infinity. */
double d = HUGE_VAL;
__asm__ __volatile__ (
" fcpy,dbl %%fr0,%%fr22\n"
" fmpy,dbl %0,%%fr22,%0\n"
" fldd 0(%%sr0,%%sp),%0"
: "+f" (d) : : "%fr22" );
}
/* Second: Division by zero. */
if (excepts & FE_DIVBYZERO)
{
double d = 1.0;
__asm__ __volatile__ (
" fcpy,dbl %%fr0,%%fr22\n"
" fdiv,dbl %0,%%fr22,%0\n"
" fldd 0(%%sr0,%%sp),%0"
: "+f" (d) : : "%fr22" );
}
/* Third: Overflow. */
if (excepts & FE_OVERFLOW)
{
double d = DBL_MAX;
__asm__ __volatile__ (
" fadd,dbl %0,%0,%0\n"
" fldd 0(%%sr0,%%sp),%0"
: "+f" (d) );
}
/* Fourth: Underflow. */
if (excepts & FE_UNDERFLOW)
{
double d = DBL_MIN;
double e = 3.0;
__asm__ __volatile__ (
" fdiv,dbl %0,%1,%0\n"
" fldd 0(%%sr0,%%sp),%0"
: "+f" (d) : "f" (e) );
}
/* Fifth: Inexact */
if (excepts & FE_INEXACT)
{
double d = M_PI;
double e = 69.69;
__asm__ __volatile__ (
" fdiv,dbl %0,%1,%%fr22\n"
" fcnvfxt,dbl,sgl %%fr22,%%fr22L\n"
" fldd 0(%%sr0,%%sp),%%fr22"
: : "f" (d), "f" (e) : "%fr22" );
}
/* Success. */
return 0;
}
libm_hidden_def (feraiseexcept)
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