1 /* Raise given exceptions.
2 Copyright (C) 1997, 1999 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
25 feraiseexcept (int excepts
)
27 /* Raise exceptions represented by EXPECTS. But we must raise only
28 one signal at a time. It is important that if the overflow/underflow
29 exception and the inexact exception are given at the same time,
30 the overflow/underflow exception follows the inexact exception. */
32 /* First: invalid exception. */
33 if ((FE_INVALID
& excepts
) != 0)
35 /* One example of a invalid operation is 0.0 / 0.0. */
37 __asm__
__volatile__ ("fldz; fdiv %%st, %%st(0); fwait" : "=t" (d
));
41 /* Next: division by zero. */
42 if ((FE_DIVBYZERO
& excepts
) != 0)
45 __asm__
__volatile__ ("fldz; fld1; fdivp %%st, %%st(1); fwait"
51 if ((FE_OVERFLOW
& excepts
) != 0)
53 /* There is no way to raise only the overflow flag. Do it the
57 /* Bah, we have to clear selected exceptions. Since there is no
58 `fldsw' instruction we have to do it the hard way. */
59 __asm__
__volatile__ ("fnstenv %0" : "=m" (*&temp
));
61 /* Set the relevant bits. */
62 temp
.__status_word
|= FE_OVERFLOW
;
64 /* Put the new data in effect. */
65 __asm__
__volatile__ ("fldenv %0" : : "m" (*&temp
));
67 /* And raise the exception. */
68 __asm__
__volatile__ ("fwait");
71 /* Next: underflow. */
72 if ((FE_UNDERFLOW
& excepts
) != 0)
74 /* There is no way to raise only the underflow flag. Do it the
78 /* Bah, we have to clear selected exceptions. Since there is no
79 `fldsw' instruction we have to do it the hard way. */
80 __asm__
__volatile__ ("fnstenv %0" : "=m" (*&temp
));
82 /* Set the relevant bits. */
83 temp
.__status_word
|= FE_UNDERFLOW
;
85 /* Put the new data in effect. */
86 __asm__
__volatile__ ("fldenv %0" : : "m" (*&temp
));
88 /* And raise the exception. */
89 __asm__
__volatile__ ("fwait");
93 if ((FE_INEXACT
& excepts
) != 0)
95 /* There is no way to raise only the inexact flag. Do it the
99 /* Bah, we have to clear selected exceptions. Since there is no
100 `fldsw' instruction we have to do it the hard way. */
101 __asm__
__volatile__ ("fnstenv %0" : "=m" (*&temp
));
103 /* Set the relevant bits. */
104 temp
.__status_word
|= FE_INEXACT
;
106 /* Put the new data in effect. */
107 __asm__
__volatile__ ("fldenv %0" : : "m" (*&temp
));
109 /* And raise the exception. */
110 __asm__
__volatile__ ("fwait");