1 /*
2 * ====================================================
3 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
4 *
5 * Developed at SunPro, a Sun Microsystems, Inc. business.
6 * Permission to use, copy, modify, and distribute this
7 * software is freely granted, provided that this notice
8 * is preserved.
9 * ====================================================
10 */
11
12 /*
13 * __ieee754_scalb(x, fn) is provided for
14 * passing various standard test suites.
15 * One should use scalbn() instead.
16 */
17
18 #include "math.h"
19 #include "math_private.h"
20 #include <errno.h>
21
__ieee754_scalb(double x,double fn)22 double __ieee754_scalb(double x, double fn)
23 {
24 if (isnan(x)||isnan(fn)) return x*fn;
25 if (!isfinite(fn)) {
26 if(fn>0.0) return x*fn;
27 else return x/(-fn);
28 }
29 if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
30 if ( fn > 65000.0) return scalbn(x, 65000);
31 if (-fn > 65000.0) return scalbn(x,-65000);
32 return scalbn(x,(int)fn);
33 }
34
35 #if defined __UCLIBC_SUSV3_LEGACY__
36 /*
37 * wrapper scalb(double x, double fn) is provided for
38 * passing various standard test suites.
39 * One should use scalbn() instead.
40 */
41 #ifndef _IEEE_LIBM
scalb(double x,double fn)42 double scalb(double x, double fn)
43 {
44 double z = __ieee754_scalb(x, fn);
45 if (_LIB_VERSION == _IEEE_)
46 return z;
47 if (!(isfinite(z) || isnan(z)) && isfinite(x))
48 return __kernel_standard(x, (double)fn, 32); /* scalb overflow */
49 if (z == 0.0 && z != x)
50 return __kernel_standard(x, (double)fn, 33); /* scalb underflow */
51 if (!isfinite(fn))
52 errno = ERANGE;
53 return z;
54 }
55 #else
56 strong_alias(__ieee754_scalb, scalb)
57 #endif
58 libm_hidden_def(scalb)
59
60 #endif /* UCLIBC_SUSV3_LEGACY */
61