1 /* Raise given exceptions.
2 Copyright (C) 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 <fpu_control.h>
21 #include <float.h>
22
23 int
__feraiseexcept(int excepts)24 __feraiseexcept (int excepts)
25 {
26 const float fp_zero = 0.0f;
27 const float fp_one = 1.0f;
28 const float fp_max = FLT_MAX;
29 const float fp_min = FLT_MIN;
30 const float fp_1e32 = 1.0e32f;
31 const float fp_two = 2.0f;
32 const float fp_three = 3.0f;
33
34 /* Raise exceptions represented by EXPECTS. But we must raise only
35 one signal at a time. It is important that if the overflow/underflow
36 exception and the inexact exception are given at the same time,
37 the overflow/underflow exception follows the inexact exception. */
38
39 /* First: invalid exception. */
40 if (FE_INVALID & excepts)
41 __asm__ __volatile__("fdiv.s $f0,%0,%0\n\t"
42 :
43 : "f"(fp_zero)
44 : "$f0");
45
46 /* Next: division by zero. */
47 if (FE_DIVBYZERO & excepts)
48 __asm__ __volatile__("fdiv.s $f0,%0,%1\n\t"
49 :
50 : "f"(fp_one), "f"(fp_zero)
51 : "$f0");
52
53 /* Next: overflow. */
54 if (FE_OVERFLOW & excepts)
55 /* There's no way to raise overflow without also raising inexact. */
56 __asm__ __volatile__("fadd.s $f0,%0,%1\n\t"
57 :
58 : "f"(fp_max), "f"(fp_1e32)
59 : "$f0");
60
61 /* Next: underflow. */
62 if (FE_UNDERFLOW & excepts)
63 __asm__ __volatile__("fdiv.s $f0,%0,%1\n\t"
64 :
65 : "f"(fp_min), "f"(fp_three)
66 : "$f0");
67
68 /* Last: inexact. */
69 if (FE_INEXACT & excepts)
70 __asm__ __volatile__("fdiv.s $f0, %0, %1\n\t"
71 :
72 : "f"(fp_two), "f"(fp_three)
73 : "$f0");
74
75 /* Success. */
76 return 0;
77 }
78
79 libm_hidden_def (__feraiseexcept) weak_alias (__feraiseexcept, feraiseexcept)
80 libm_hidden_weak (feraiseexcept)
81