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 <fpu_control.h>
21 #include <math.h>
22
23 int
feraiseexcept(int excepts)24 feraiseexcept (int excepts)
25 {
26 if (excepts == 0)
27 return 0;
28
29 /* Raise exceptions represented by EXPECTS. */
30
31 if (excepts & FE_INEXACT)
32 {
33 double d = 1.0, x = 3.0;
34 __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
35 }
36
37 if (excepts & FE_UNDERFLOW)
38 {
39 long double d = LDBL_MIN, x = 10;
40 __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
41 }
42
43 if (excepts & FE_OVERFLOW)
44 {
45 long double d = LDBL_MAX;
46 __asm__ __volatile__ ("fmul %0, %0" : "+d" (d) : "d" (d));
47 }
48
49 if (excepts & FE_DIVBYZERO)
50 {
51 double d = 1.0, x = 0.0;
52 __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
53 }
54
55 if (excepts & FE_INVALID)
56 {
57 double d = HUGE_VAL, x = 0.0;
58 __asm__ __volatile__ ("fmul %1, %0" : "+d" (d) : "d" (x));
59 }
60
61 {
62 /* Restore flag fields. */
63 fpu_control_t cw;
64 _FPU_GETCW (cw);
65 cw |= (excepts & FE_ALL_EXCEPT);
66 _FPU_SETCW (cw);
67 }
68
69 return 0;
70 }
71