1 /* Copyright (C) 2011-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <errno.h>
19 #include <math.h>
20 #include <math_private.h>
21 #include <math-svid-compat.h>
22
23
24 #if LIBM_SVID_COMPAT
25 static long double
26 __attribute__ ((noinline))
sysv_scalbl(long double x,long double fn)27 sysv_scalbl (long double x, long double fn)
28 {
29 long double z = __ieee754_scalbl (x, fn);
30
31 if (__glibc_unlikely (isinf (z)))
32 {
33 if (isfinite (x))
34 return __kernel_standard_l (x, fn, 232); /* scalb overflow */
35 else
36 __set_errno (ERANGE);
37 }
38 else if (__builtin_expect (z == 0.0L, 0) && z != x)
39 return __kernel_standard_l (x, fn, 233); /* scalb underflow */
40
41 return z;
42 }
43
44
45 /* Wrapper scalbl */
46 long double
__scalbl(long double x,long double fn)47 __scalbl (long double x, long double fn)
48 {
49 if (__glibc_unlikely (_LIB_VERSION == _SVID_))
50 return sysv_scalbl (x, fn);
51 else
52 {
53 long double z = __ieee754_scalbl (x, fn);
54
55 if (__glibc_unlikely (!isfinite (z) || z == 0.0L))
56 {
57 if (isnan (z))
58 {
59 if (!isnan (x) && !isnan (fn))
60 __set_errno (EDOM);
61 }
62 else if (isinf (z))
63 {
64 if (!isinf (x) && !isinf (fn))
65 __set_errno (ERANGE);
66 }
67 else
68 {
69 /* z == 0. */
70 if (x != 0.0L && !isinf (fn))
71 __set_errno (ERANGE);
72 }
73 }
74 return z;
75 }
76 }
77 weak_alias (__scalbl, scalbl)
78 #endif
79