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w_scalb.c
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1 
2 /* @(#)w_scalb.c 1.3 95/01/18 */
3 /*
4  * ====================================================
5  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6  *
7  * Developed at SunSoft, a Sun Microsystems, Inc. business.
8  * Permission to use, copy, modify, and distribute this
9  * software is freely granted, provided that this notice
10  * is preserved.
11  * ====================================================
12  */
13 
14 /*
15  * wrapper scalb(double x, double fn) is provide for
16  * passing various standard test suite. One
17  * should use scalbn() instead.
18  */
19 
20 #include "fdlibm.h"
21 
22 #include <errno.h>
23 
24 #ifdef __STDC__
25 #ifdef _SCALB_INT
26  double scalb(double x, int fn) /* wrapper scalb */
27 #else
28  double scalb(double x, double fn) /* wrapper scalb */
29 #endif
30 #else
31  double scalb(x,fn) /* wrapper scalb */
32 #ifdef _SCALB_INT
33  double x; int fn;
34 #else
35  double x,fn;
36 #endif
37 #endif
38 {
39 #ifdef _IEEE_LIBM
40  return __ieee754_scalb(x,fn);
41 #else
42  double z;
43  z = __ieee754_scalb(x,fn);
44  if(_LIB_VERSION == _IEEE_) return z;
45  if(!(finite(z)||isnan(z))&&finite(x)) {
46  return __kernel_standard(x,(double)fn,32); /* scalb overflow */
47  }
48  if(z==0.0&&z!=x) {
49  return __kernel_standard(x,(double)fn,33); /* scalb underflow */
50  }
51 #ifndef _SCALB_INT
52  if(!finite(fn)) errno = ERANGE;
53 #endif
54  return z;
55 #endif
56 }