1 /* Raise given exceptions.
2    Copyright (C) 1997-2022 Free Software Foundation, Inc.
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
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <fenv.h>
20 #include <float.h>
21 #include <fpu_control.h>
22 #include <math.h>
23 
24 int
__feraiseexcept(int excepts)25 __feraiseexcept (int excepts)
26 {
27   if (excepts == 0)
28     return 0;
29 
30   /* Raise exceptions represented by EXPECTS.  */
31 
32   if (excepts & FE_INEXACT)
33   {
34     double d = 1.0, x = 3.0;
35     __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
36   }
37 
38   if (excepts & FE_UNDERFLOW)
39   {
40     long double d = LDBL_MIN, x = 10;
41     __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
42   }
43 
44   if (excepts & FE_OVERFLOW)
45   {
46     long double d = LDBL_MAX;
47     __asm__ __volatile__ ("fmul %0, %0" : "+d" (d) : "d" (d));
48   }
49 
50   if (excepts & FE_DIVBYZERO)
51   {
52     double d = 1.0, x = 0.0;
53     __asm__ __volatile__ ("fdiv %1, %0" : "+d" (d) : "d" (x));
54   }
55 
56   if (excepts & FE_INVALID)
57   {
58     double d = HUGE_VAL, x = 0.0;
59     __asm__ __volatile__ ("fmul %1, %0" : "+d" (d) : "d" (x));
60   }
61 
62   {
63     /* Restore flag fields.  */
64     fpu_control_t cw;
65     _FPU_GETCW (cw);
66     cw |= (excepts & FE_ALL_EXCEPT);
67     _FPU_SETCW (cw);
68   }
69 
70   return 0;
71 }
72 libm_hidden_def (__feraiseexcept)
73 weak_alias (__feraiseexcept, feraiseexcept)
74 libm_hidden_weak (feraiseexcept)
75