1 /* Raise given exceptions.
2 Copyright (C) 1997-2025 Free Software Foundation, Inc.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <fenv.h>
19 #include <float.h>
20 #include <math.h>
21 #include "math-barriers.h"
22
23 int
feraiseexcept(int excepts)24 feraiseexcept (int excepts)
25 {
26 static const struct {
27 double zero, one, max, min, pi;
28 } c = {
29 0.0, 1.0, DBL_MAX, DBL_MIN, M_PI
30 };
31 double d;
32
33 /* Raise exceptions represented by EXPECTS. But we must raise only
34 one signal at a time. It is important the if the overflow/underflow
35 exception and the inexact exception are given at the same time,
36 the overflow/underflow exception follows the inexact exception. */
37
38 /* First: invalid exception. */
39 if ((FE_INVALID & excepts) != 0)
40 {
41 /* One example of an invalid operation is 0/0. */
42 __asm__ ("" : "=e" (d) : "0" (c.zero));
43 d /= c.zero;
44 math_force_eval (d);
45 }
46
47 /* Next: division by zero. */
48 if ((FE_DIVBYZERO & excepts) != 0)
49 {
50 __asm__ ("" : "=e" (d) : "0" (c.one));
51 d /= c.zero;
52 math_force_eval (d);
53 }
54
55 /* Next: overflow. */
56 if ((FE_OVERFLOW & excepts) != 0)
57 {
58 __asm__ ("" : "=e" (d) : "0" (c.max));
59 d *= d;
60 math_force_eval (d);
61 }
62
63 /* Next: underflow. */
64 if ((FE_UNDERFLOW & excepts) != 0)
65 {
66 __asm__ ("" : "=e" (d) : "0" (c.min));
67 d *= d;
68 math_force_eval (d);
69 }
70
71 /* Last: inexact. */
72 if ((FE_INEXACT & excepts) != 0)
73 {
74 __asm__ ("" : "=e" (d) : "0" (c.one));
75 d /= c.pi;
76 math_force_eval (d);
77 }
78
79 /* Success. */
80 return 0;
81 }
82