1/* origin: FreeBSD /usr/src/lib/msun/src/e_scalbf.c */ 2/* 3 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 4 */ 5/* 6 * ==================================================== 7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 8 * 9 * Developed at SunPro, a Sun Microsystems, Inc. business. 10 * Permission to use, copy, modify, and distribute this 11 * software is freely granted, provided that this notice 12 * is preserved. 13 * ==================================================== 14 */ 15 16#define _GNU_SOURCE 17#include <math.h> 18 19float scalbf(float x, float fn) { 20 if (isnan(x) || isnan(fn)) 21 return x * fn; 22 if (!isfinite(fn)) { 23 if (fn > 0.0f) 24 return x * fn; 25 else 26 return x / (-fn); 27 } 28 if (rintf(fn) != fn) 29 return (fn - fn) / (fn - fn); 30 if (fn > 65000.0f) 31 return scalbnf(x, 65000); 32 if (-fn > 65000.0f) 33 return scalbnf(x, -65000); 34 return scalbnf(x, (int)fn); 35} 36