1/* Single-precision math error handling.
2 Copyright (C) 2017-2020 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 "math_config.h"
20
21#if WANT_ERRNO
22# include <errno.h>
23/* NOINLINE reduces code size. */
24NOINLINE static float
25with_errnof (float y, int e)
26{
27 errno = e;
28 return y;
29}
30#else
31# define with_errnof(x, e) (x)
32#endif
33
34/* NOINLINE prevents fenv semantics breaking optimizations. */
35NOINLINE static float
36xflowf (uint32_t sign, float y)
37{
38 y = (sign ? -y : y) * y;
39 return with_errnof (y, ERANGE);
40}
41
42attribute_hidden float
43__math_uflowf (uint32_t sign)
44{
45 return xflowf (sign, 0x1p-95f);
46}
47
48#if WANT_ERRNO_UFLOW
49/* Underflows to zero in some non-nearest rounding mode, setting errno
50 is valid even if the result is non-zero, but in the subnormal range. */
51attribute_hidden float
52__math_may_uflowf (uint32_t sign)
53{
54 return xflowf (sign, 0x1.4p-75f);
55}
56#endif
57
58attribute_hidden float
59__math_oflowf (uint32_t sign)
60{
61 return xflowf (sign, 0x1p97f);
62}
63
64attribute_hidden float
65__math_divzerof (uint32_t sign)
66{
67 float y = 0;
68 return with_errnof ((sign ? -1 : 1) / y, ERANGE);
69}
70
71attribute_hidden float
72__math_invalidf (float x)
73{
74 float y = (x - x) / (x - x);
75 return isnan (x) ? y : with_errnof (y, EDOM);
76}
77