xref: /aosp_15_r20/external/fdlibm/e_scalb.c (revision 1e651e1ef2b613db2c4b29ae59c1de74cf0222ae)
1*1e651e1eSRoland Levillain 
2*1e651e1eSRoland Levillain /* @(#)e_scalb.c 1.3 95/01/18 */
3*1e651e1eSRoland Levillain /*
4*1e651e1eSRoland Levillain  * ====================================================
5*1e651e1eSRoland Levillain  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6*1e651e1eSRoland Levillain  *
7*1e651e1eSRoland Levillain  * Developed at SunSoft, a Sun Microsystems, Inc. business.
8*1e651e1eSRoland Levillain  * Permission to use, copy, modify, and distribute this
9*1e651e1eSRoland Levillain  * software is freely granted, provided that this notice
10*1e651e1eSRoland Levillain  * is preserved.
11*1e651e1eSRoland Levillain  * ====================================================
12*1e651e1eSRoland Levillain  */
13*1e651e1eSRoland Levillain 
14*1e651e1eSRoland Levillain /*
15*1e651e1eSRoland Levillain  * __ieee754_scalb(x, fn) is provide for
16*1e651e1eSRoland Levillain  * passing various standard test suite. One
17*1e651e1eSRoland Levillain  * should use ieee_scalbn() instead.
18*1e651e1eSRoland Levillain  */
19*1e651e1eSRoland Levillain 
20*1e651e1eSRoland Levillain #include "fdlibm.h"
21*1e651e1eSRoland Levillain 
22*1e651e1eSRoland Levillain #ifdef _SCALB_INT
23*1e651e1eSRoland Levillain #ifdef __STDC__
__ieee754_scalb(double x,int fn)24*1e651e1eSRoland Levillain 	double __ieee754_scalb(double x, int fn)
25*1e651e1eSRoland Levillain #else
26*1e651e1eSRoland Levillain 	double __ieee754_scalb(x,fn)
27*1e651e1eSRoland Levillain 	double x; int fn;
28*1e651e1eSRoland Levillain #endif
29*1e651e1eSRoland Levillain #else
30*1e651e1eSRoland Levillain #ifdef __STDC__
31*1e651e1eSRoland Levillain 	double __ieee754_scalb(double x, double fn)
32*1e651e1eSRoland Levillain #else
33*1e651e1eSRoland Levillain 	double __ieee754_scalb(x,fn)
34*1e651e1eSRoland Levillain 	double x, fn;
35*1e651e1eSRoland Levillain #endif
36*1e651e1eSRoland Levillain #endif
37*1e651e1eSRoland Levillain {
38*1e651e1eSRoland Levillain #ifdef _SCALB_INT
39*1e651e1eSRoland Levillain 	return ieee_scalbn(x,fn);
40*1e651e1eSRoland Levillain #else
41*1e651e1eSRoland Levillain 	if (ieee_isnan(x)||ieee_isnan(fn)) return x*fn;
42*1e651e1eSRoland Levillain 	if (!ieee_finite(fn)) {
43*1e651e1eSRoland Levillain 	    if(fn>0.0) return x*fn;
44*1e651e1eSRoland Levillain 	    else       return x/(-fn);
45*1e651e1eSRoland Levillain 	}
46*1e651e1eSRoland Levillain 	if (ieee_rint(fn)!=fn) return (fn-fn)/(fn-fn);
47*1e651e1eSRoland Levillain 	if ( fn > 65000.0) return ieee_scalbn(x, 65000);
48*1e651e1eSRoland Levillain 	if (-fn > 65000.0) return ieee_scalbn(x,-65000);
49*1e651e1eSRoland Levillain 	return ieee_scalbn(x,(int)fn);
50*1e651e1eSRoland Levillain #endif
51*1e651e1eSRoland Levillain }
52