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e70c1768 | 1 | /* Double-precision math error handling. |
6d7e8eda | 2 | Copyright (C) 2018-2023 Free Software Foundation, Inc. |
e70c1768 SN |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
e70c1768 SN |
18 | |
19 | #include <math-barriers.h> | |
20 | #include "math_config.h" | |
21 | ||
22 | #if WANT_ERRNO | |
23 | #include <errno.h> | |
24 | /* NOINLINE reduces code size and avoids making math functions non-leaf | |
25 | when the error handling is inlined. */ | |
26 | NOINLINE static double | |
27 | with_errno (double y, int e) | |
28 | { | |
29 | errno = e; | |
30 | return y; | |
31 | } | |
32 | #else | |
33 | #define with_errno(x, e) (x) | |
34 | #endif | |
35 | ||
16439f41 AZN |
36 | attribute_hidden double |
37 | __math_edom (double y) | |
38 | { | |
39 | return with_errno (y, EDOM); | |
40 | } | |
41 | ||
e70c1768 SN |
42 | /* NOINLINE reduces code size. */ |
43 | NOINLINE static double | |
44 | xflow (uint32_t sign, double y) | |
45 | { | |
46 | y = math_opt_barrier (sign ? -y : y) * y; | |
47 | return with_errno (y, ERANGE); | |
48 | } | |
49 | ||
50 | attribute_hidden double | |
51 | __math_uflow (uint32_t sign) | |
52 | { | |
53 | return xflow (sign, 0x1p-767); | |
54 | } | |
55 | ||
56 | #if WANT_ERRNO_UFLOW | |
57 | /* Underflows to zero in some non-nearest rounding mode, setting errno | |
58 | is valid even if the result is non-zero, but in the subnormal range. */ | |
59 | attribute_hidden double | |
60 | __math_may_uflow (uint32_t sign) | |
61 | { | |
62 | return xflow (sign, 0x1.8p-538); | |
63 | } | |
64 | #endif | |
65 | ||
66 | attribute_hidden double | |
67 | __math_oflow (uint32_t sign) | |
68 | { | |
69 | return xflow (sign, 0x1p769); | |
70 | } | |
71 | ||
72 | attribute_hidden double | |
73 | __math_divzero (uint32_t sign) | |
74 | { | |
75 | double y = math_opt_barrier (sign ? -1.0 : 1.0) / 0.0; | |
76 | return with_errno (y, ERANGE); | |
77 | } | |
78 | ||
79 | attribute_hidden double | |
80 | __math_invalid (double x) | |
81 | { | |
82 | double y = (x - x) / (x - x); | |
83 | return isnan (x) ? y : with_errno (y, EDOM); | |
84 | } | |
85 | ||
86 | /* Check result and set errno if necessary. */ | |
87 | ||
88 | attribute_hidden double | |
89 | __math_check_uflow (double y) | |
90 | { | |
91 | return y == 0.0 ? with_errno (y, ERANGE) : y; | |
92 | } | |
93 | ||
94 | attribute_hidden double | |
95 | __math_check_oflow (double y) | |
96 | { | |
97 | return isinf (y) ? with_errno (y, ERANGE) : y; | |
98 | } |