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
22 #if defined(__UCLIBC_HAS_FENV__)
23 #include <errno.h>
24
25 static float
26 __attribute__ ((noinline))
sysv_scalbf(float x,float fn)27 sysv_scalbf (float x, float fn)
28 {
29 float z = (float) __ieee754_scalb ((double) x, (double) fn);
30
31 if (__builtin_expect (isinf (z),0))
32 {
33 if (isfinite (x))
34 return __kernel_standard_f (x, fn, 132); /* scalb overflow */
35 else
36 __set_errno (ERANGE);
37 }
38 else if (__builtin_expect (z == 0.0f, 0) && z != x)
39 return __kernel_standard_f (x, fn, 133); /* scalb underflow */
40
41 return z;
42 }
43 #endif
44
45 /* Wrapper scalbf */
46 float
scalbf(float x,float fn)47 scalbf (float x, float fn)
48 {
49 #if defined(__UCLIBC_HAS_FENV__)
50 if (__builtin_expect (_LIB_VERSION == _SVID_, 0))
51 return sysv_scalbf (x, fn);
52 else
53 {
54 float z = (float) __ieee754_scalb ((double) x, (double) fn);
55
56 if (__builtin_expect (!isfinite (z) || z == 0.0f, 0))
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 != 0.0f && !isinf (fn))
72 __set_errno (ERANGE);
73 }
74 }
75 return z;
76 }
77 #else
78 return (float) __ieee754_scalb ((double) x, (double) fn);
79 #endif /* __UCLIBC_HAS_FENV__ */
80 }
81