1 | /* Copyright (C) 2011-2020 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@gmail.com>, 2011. |
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 <errno.h> |
20 | #include <math.h> |
21 | #include <math_private.h> |
22 | #include <math-svid-compat.h> |
23 | |
24 | |
25 | #if LIBM_SVID_COMPAT |
26 | static long double |
27 | __attribute__ ((noinline)) |
28 | sysv_scalbl (long double x, long double fn) |
29 | { |
30 | long double z = __ieee754_scalbl (x, fn); |
31 | |
32 | if (__glibc_unlikely (isinf (z))) |
33 | { |
34 | if (isfinite (x)) |
35 | return __kernel_standard_l (x, fn, 232); /* scalb overflow */ |
36 | else |
37 | __set_errno (ERANGE); |
38 | } |
39 | else if (__builtin_expect (z == 0.0L, 0) && z != x) |
40 | return __kernel_standard_l (x, fn, 233); /* scalb underflow */ |
41 | |
42 | return z; |
43 | } |
44 | |
45 | |
46 | /* Wrapper scalbl */ |
47 | long double |
48 | __scalbl (long double x, long double fn) |
49 | { |
50 | if (__glibc_unlikely (_LIB_VERSION == _SVID_)) |
51 | return sysv_scalbl (x, fn); |
52 | else |
53 | { |
54 | long double z = __ieee754_scalbl (x, fn); |
55 | |
56 | if (__glibc_unlikely (!isfinite (z) || z == 0.0L)) |
57 | { |
58 | if (isnan (z)) |
59 | { |
60 | if (!isnan (x) && !isnan (fn)) |
61 | __set_errno (EDOM); |
62 | } |
63 | else if (isinf (z)) |
64 | { |
65 | if (!isinf (x) && !isinf (fn)) |
66 | __set_errno (ERANGE); |
67 | } |
68 | else |
69 | { |
70 | /* z == 0. */ |
71 | if (x != 0.0L && !isinf (fn)) |
72 | __set_errno (ERANGE); |
73 | } |
74 | } |
75 | return z; |
76 | } |
77 | } |
78 | weak_alias (__scalbl, scalbl) |
79 | #endif |
80 | |