1 | /* Raise given exceptions. |
2 | Copyright (C) 2000-2024 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_libc.h> |
20 | #include <float.h> |
21 | #include <math.h> |
22 | |
23 | |
24 | static __inline__ void |
25 | fexceptdiv (float d, float e) |
26 | { |
27 | __asm__ __volatile__ ("debr %0,%1" : : "f" (d), "f" (e) ); |
28 | } |
29 | |
30 | static __inline__ void |
31 | fexceptadd (float d, float e) |
32 | { |
33 | __asm__ __volatile__ ("aebr %0,%1" : : "f" (d), "f" (e) ); |
34 | } |
35 | |
36 | #ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT |
37 | static __inline__ void |
38 | fexceptround (double e) |
39 | { |
40 | float d; |
41 | /* Load rounded from double to float with M3 = round toward 0, M4 = Suppress |
42 | IEEE-inexact exception. |
43 | In case of e=0x1p128 and the overflow-mask bit is zero, only the |
44 | IEEE-overflow flag is set. If overflow-mask bit is one, DXC field is set to |
45 | 0x20 "IEEE overflow, exact". |
46 | In case of e=0x1p-150 and the underflow-mask bit is zero, only the |
47 | IEEE-underflow flag is set. If underflow-mask bit is one, DXC field is set |
48 | to 0x10 "IEEE underflow, exact". |
49 | This instruction is available with a zarch machine >= z196. */ |
50 | __asm__ __volatile__ ("ledbra %0,5,%1,4" : "=f" (d) : "f" (e) ); |
51 | } |
52 | #endif |
53 | |
54 | int |
55 | __feraiseexcept (int excepts) |
56 | { |
57 | /* Raise exceptions represented by EXPECTS. But we must raise only |
58 | one signal at a time. It is important that if the overflow/underflow |
59 | exception and the inexact exception are given at the same time, |
60 | the overflow/underflow exception follows the inexact exception. */ |
61 | |
62 | /* First: invalid exception. */ |
63 | if (FE_INVALID & excepts) |
64 | fexceptdiv (d: 0.0, e: 0.0); |
65 | |
66 | /* Next: division by zero. */ |
67 | if (FE_DIVBYZERO & excepts) |
68 | fexceptdiv (d: 1.0, e: 0.0); |
69 | |
70 | /* Next: overflow. */ |
71 | if (FE_OVERFLOW & excepts) |
72 | { |
73 | #ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT |
74 | fexceptround (0x1p128); |
75 | #else |
76 | /* If overflow-mask bit is zero, both IEEE-overflow and IEEE-inexact flags |
77 | are set. If overflow-mask bit is one, DXC field is set to 0x2C "IEEE |
78 | overflow, inexact and incremented". */ |
79 | fexceptadd (FLT_MAX, e: 1.0e32); |
80 | #endif |
81 | } |
82 | |
83 | /* Next: underflow. */ |
84 | if (FE_UNDERFLOW & excepts) |
85 | { |
86 | #ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT |
87 | fexceptround (0x1p-150); |
88 | #else |
89 | /* If underflow-mask bit is zero, both IEEE-underflow and IEEE-inexact |
90 | flags are set. If underflow-mask bit is one, DXC field is set to 0x1C |
91 | "IEEE underflow, inexact and incremented". */ |
92 | fexceptdiv (FLT_MIN, e: 3.0); |
93 | #endif |
94 | } |
95 | |
96 | /* Last: inexact. */ |
97 | if (FE_INEXACT & excepts) |
98 | fexceptdiv (d: 2.0, e: 3.0); |
99 | |
100 | /* Success. */ |
101 | return 0; |
102 | } |
103 | libm_hidden_def (__feraiseexcept) |
104 | weak_alias (__feraiseexcept, feraiseexcept) |
105 | libm_hidden_weak (feraiseexcept) |
106 | |