OpenLibm/src/e_scalb.c

48 lines
1.1 KiB
C

/* @(#)e_scalb.c 1.3 95/01/18 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunSoft, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#include "cdefs-compat.h"
//__FBSDID("$FreeBSD: src/lib/msun/src/e_scalb.c,v 1.13 2008/02/22 02:30:35 das Exp $");
/*
* __ieee754_scalb(x, fn) is provide for
* passing various standard test suite. One
* should use scalbn() instead.
*/
#include "openlibm.h"
#include "math_private.h"
#ifdef _SCALB_INT
double
__ieee754_scalb(double x, int fn)
#else
double
__ieee754_scalb(double x, double fn)
#endif
{
#ifdef _SCALB_INT
return scalbn(x,fn);
#else
if (isnan(x)||isnan(fn)) return x*fn;
if (!finite(fn)) {
if(fn>0.0) return x*fn;
else return x/(-fn);
}
if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
if ( fn > 65000.0) return scalbn(x, 65000);
if (-fn > 65000.0) return scalbn(x,-65000);
return scalbn(x,(int)fn);
#endif
}