glibc/sysdeps/m68k/coldfire/fpu/fraiseexcpt.c
2014-02-10 20:22:40 +01:00

67 lines
2.2 KiB
C

/* Raise given exceptions.
Copyright (C) 2006-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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>
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.
The Coldfire FPU allows an exception to be raised by asserting
the associated EXC bit and then executing an arbitrary arithmetic
instruction. fmove.l is classified as an arithmetic instruction
and suffices for this purpose.
We therefore raise an exception by setting both the EXC and AEXC
bit associated with the exception (the former being 6 bits to the
left of the latter) and then loading the longword at (%sp) into an
FP register. */
inline void
raise_one_exception (int mask)
{
if (excepts & mask)
{
int fpsr;
double unused;
asm volatile ("fmove%.l %/fpsr,%0" : "=d" (fpsr));
fpsr |= (mask << 6) | mask;
asm volatile ("fmove%.l %0,%/fpsr" :: "d" (fpsr));
asm volatile ("fmove%.l (%%sp),%0" : "=f" (unused));
}
}
raise_one_exception (FE_INVALID);
raise_one_exception (FE_DIVBYZERO);
raise_one_exception (FE_OVERFLOW);
raise_one_exception (FE_UNDERFLOW);
raise_one_exception (FE_INEXACT);
/* Success. */
return 0;
}
libm_hidden_def (feraiseexcept)