glibc/sysdeps/vax/infnan.c
1995-02-18 01:27:10 +00:00

63 lines
1.7 KiB
C

/* Copyright (C) 1991, 1992, 1995 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 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., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#ifndef __GNUC__
#error This file uses GNU C extensions; you must compile with GCC.
#else
#include <ansidecl.h>
#include <errno.h>
#include <math.h>
/* Deal with an infinite or NaN result.
If ERROR is ERANGE, result is +Inf;
if ERROR is - ERANGE, result is -Inf;
otherwise result is NaN.
This will set `errno' to either ERANGE or EDOM,
and may return an infinity or NaN, or may do something else. */
double
DEFUN(__infnan, (error), int error)
{
switch (error)
{
case ERANGE:
errno = ERANGE;
break;
case - ERANGE:
errno = ERANGE;
break;
default:
errno = EDOM;
break;
}
/* Trigger a reserved operand fault. */
{
double result;
asm volatile("emodd %1, %1, %2, %0, %0" : "=r" (result) :
"i" (0), "i" (0x8000));
return result;
}
}
#endif
weak_alias (__infnan, infnan)