1 /* w_log10f.c -- float version of w_log10.c. 2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com. 3 */ 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 #include <sys/cdefs.h> 17 #if defined(LIBM_SCCS) && !defined(lint) 18 __RCSID("$NetBSD: w_log2f.c,v 1.1 2005/07/21 16:58:39 christos Exp $"); 19 #endif 20 21 /* 22 * wrapper log2f(X) 23 */ 24 25 #include "math.h" 26 #include "math_private.h" 27 28 29 float 30 log2f(float x) /* wrapper log2f */ 31 { 32 #ifdef _IEEE_LIBM 33 return __ieee754_log2f(x); 34 #else 35 float z; 36 z = __ieee754_log2f(x); 37 if(_LIB_VERSION == _IEEE_ || isnanf(x)) return z; 38 if(x<=(float)0.0) { 39 if(x==(float)0.0) 40 /* log2(0) */ 41 return (float)__kernel_standard((double)x,(double)x,148); 42 else 43 /* log2(x<0) */ 44 return (float)__kernel_standard((double)x,(double)x,149); 45 } else 46 return z; 47 #endif 48 } 49