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c9cf6dde | 1 | /* Raise given exceptions. |
f7a9f785 | 2 | Copyright (C) 2001-2016 Free Software Foundation, Inc. |
c9cf6dde AJ |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
c9cf6dde AJ |
18 | |
19 | #include <fenv.h> | |
20 | #include <math.h> | |
21 | ||
22 | int | |
714fad23 | 23 | __feraiseexcept (int excepts) |
c9cf6dde AJ |
24 | { |
25 | /* Raise exceptions represented by EXPECTS. But we must raise only | |
26 | one signal at a time. It is important that if the overflow/underflow | |
27 | exception and the inexact exception are given at the same time, | |
28 | the overflow/underflow exception follows the inexact exception. */ | |
29 | ||
30 | /* First: invalid exception. */ | |
31 | if ((FE_INVALID & excepts) != 0) | |
32 | { | |
c0c3f78a | 33 | /* One example of an invalid operation is 0.0 / 0.0. */ |
c9cf6dde AJ |
34 | float f = 0.0; |
35 | ||
36 | __asm__ __volatile__ ("divss %0, %0 " : : "x" (f)); | |
37 | (void) &f; | |
38 | } | |
39 | ||
40 | /* Next: division by zero. */ | |
41 | if ((FE_DIVBYZERO & excepts) != 0) | |
42 | { | |
43 | float f = 1.0; | |
44 | float g = 0.0; | |
45 | ||
46 | __asm__ __volatile__ ("divss %1, %0" : : "x" (f), "x" (g)); | |
47 | (void) &f; | |
48 | } | |
49 | ||
50 | /* Next: overflow. */ | |
51 | if ((FE_OVERFLOW & excepts) != 0) | |
52 | { | |
53 | /* XXX: Is it ok to only set the x87 FPU? */ | |
54 | /* There is no way to raise only the overflow flag. Do it the | |
55 | hard way. */ | |
56 | fenv_t temp; | |
57 | ||
58 | /* Bah, we have to clear selected exceptions. Since there is no | |
59 | `fldsw' instruction we have to do it the hard way. */ | |
60 | __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp)); | |
61 | ||
62 | /* Set the relevant bits. */ | |
63 | temp.__status_word |= FE_OVERFLOW; | |
64 | ||
65 | /* Put the new data in effect. */ | |
66 | __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp)); | |
67 | ||
68 | /* And raise the exception. */ | |
69 | __asm__ __volatile__ ("fwait"); | |
70 | } | |
71 | ||
72 | /* Next: underflow. */ | |
73 | if ((FE_UNDERFLOW & excepts) != 0) | |
74 | { | |
75 | /* XXX: Is it ok to only set the x87 FPU? */ | |
76 | /* There is no way to raise only the underflow flag. Do it the | |
77 | hard way. */ | |
78 | fenv_t temp; | |
79 | ||
80 | /* Bah, we have to clear selected exceptions. Since there is no | |
81 | `fldsw' instruction we have to do it the hard way. */ | |
82 | __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp)); | |
83 | ||
84 | /* Set the relevant bits. */ | |
85 | temp.__status_word |= FE_UNDERFLOW; | |
86 | ||
87 | /* Put the new data in effect. */ | |
88 | __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp)); | |
89 | ||
90 | /* And raise the exception. */ | |
91 | __asm__ __volatile__ ("fwait"); | |
92 | } | |
93 | ||
94 | /* Last: inexact. */ | |
95 | if ((FE_INEXACT & excepts) != 0) | |
96 | { | |
97 | /* XXX: Is it ok to only set the x87 FPU? */ | |
98 | /* There is no way to raise only the inexact flag. Do it the | |
99 | hard way. */ | |
100 | fenv_t temp; | |
101 | ||
102 | /* Bah, we have to clear selected exceptions. Since there is no | |
103 | `fldsw' instruction we have to do it the hard way. */ | |
104 | __asm__ __volatile__ ("fnstenv %0" : "=m" (*&temp)); | |
105 | ||
106 | /* Set the relevant bits. */ | |
107 | temp.__status_word |= FE_INEXACT; | |
108 | ||
109 | /* Put the new data in effect. */ | |
110 | __asm__ __volatile__ ("fldenv %0" : : "m" (*&temp)); | |
111 | ||
112 | /* And raise the exception. */ | |
113 | __asm__ __volatile__ ("fwait"); | |
114 | } | |
115 | ||
116 | /* Success. */ | |
117 | return 0; | |
118 | } | |
0747f818 JM |
119 | libm_hidden_def (__feraiseexcept) |
120 | weak_alias (__feraiseexcept, feraiseexcept) | |
121 | libm_hidden_weak (feraiseexcept) |