1/* Copyright (C) 2011-2016 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 <http://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <math.h>
21#include <math_private.h>
22
23
24static double
25__attribute__ ((noinline))
26sysv_scalb (double x, double fn)
27{
28 double z = __ieee754_scalb (x, fn);
29
30 if (__glibc_unlikely (isinf (z)))
31 {
32 if (isfinite (x))
33 return __kernel_standard (x, fn, 32); /* scalb overflow */
34 else
35 __set_errno (ERANGE);
36 }
37 else if (__builtin_expect (z == 0.0, 0) && z != x)
38 return __kernel_standard (x, fn, 33); /* scalb underflow */
39
40 return z;
41}
42
43
44/* Wrapper scalb */
45double
46__scalb (double x, double fn)
47{
48 if (__glibc_unlikely (_LIB_VERSION == _SVID_))
49 return sysv_scalb (x, fn);
50 else
51 {
52 double z = __ieee754_scalb (x, fn);
53
54 if (__glibc_unlikely (!isfinite (z) || z == 0.0))
55 {
56 if (isnan (z))
57 {
58 if (!isnan (x) && !isnan (fn))
59 __set_errno (EDOM);
60 }
61 else if (isinf (z))
62 {
63 if (!isinf (x) && !isinf (fn))
64 __set_errno (ERANGE);
65 }
66 else
67 {
68 /* z == 0. */
69 if (x != 0.0 && !isinf (fn))
70 __set_errno (ERANGE);
71 }
72 }
73 return z;
74 }
75}
76weak_alias (__scalb, scalb)
77#ifdef NO_LONG_DOUBLE
78strong_alias (__scalb, __scalbl)
79weak_alias (__scalb, scalbl)
80#endif
81