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 <math.h>
20 #include "math_private.h"
21 #if defined(__UCLIBC_HAS_FENV__)
22 #include <errno.h>
23 #endif
24
25 #if !defined __NO_LONG_DOUBLE_MATH
26 # if defined(__UCLIBC_HAS_FENV__)
27 static long double
28 __attribute__ ((noinline))
sysv_scalbl(long double x,long double fn)29 sysv_scalbl (long double x, long double fn)
30 {
31 long double z = (long double) __ieee754_scalb ((double) x, (double) fn);
32
33 if (__builtin_expect (isinf (z), 0))
34 {
35 if (isfinite (x))
36 return __kernel_standard_l (x, fn, 232); /* scalb overflow */
37 else
38 __set_errno (ERANGE);
39 }
40 else if (__builtin_expect (z == 0.0L, 0) && z != x)
41 return __kernel_standard_l (x, fn, 233); /* scalb underflow */
42
43 return z;
44 }
45 # endif /* __UCLIBC_HAS_FENV__ */
46
47 /* Wrapper scalbl */
48 long double
scalbl(long double x,long double fn)49 scalbl (long double x, long double fn)
50 {
51 # if defined(__UCLIBC_HAS_FENV__)
52 if (__builtin_expect (_LIB_VERSION == _SVID_, 0))
53 return sysv_scalbl (x, fn);
54 else
55 {
56 long double z = (long double) __ieee754_scalb ((double) x, (double) fn);
57
58 if (__builtin_expect (!isfinite (z) || z == 0.0L, 0))
59 {
60 if (isnan (z))
61 {
62 if (!isnan (x) && !isnan (fn))
63 __set_errno (EDOM);
64 }
65 else if (isinf (z))
66 {
67 if (!isinf (x) && !isinf (fn))
68 __set_errno (ERANGE);
69 }
70 else
71 {
72 /* z == 0. */
73 if (x != 0.0L && !isinf (fn))
74 __set_errno (ERANGE);
75 }
76 }
77 return z;
78 }
79 # else
80 return (long double) __ieee754_scalb ((double) x, (double) fn);
81 # endif /* __UCLIBC_HAS_FENV__ */
82 }
83 #endif /* __NO_LONG_DOUBLE_MATH */
84