1 /* @(#)w_log10.c 5.1 93/09/24 */ 2 /* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13 #include <sys/cdefs.h> 14 #if defined(LIBM_SCCS) && !defined(lint) 15 __RCSID("$NetBSD: w_log2.c,v 1.2 2024/07/16 14:52:50 riastradh Exp $"); 16 #endif 17 18 /* 19 * wrapper log2(X) 20 */ 21 22 #include "namespace.h" 23 24 #include "math.h" 25 #include "math_private.h" 26 27 #ifndef __HAVE_LONG_DOUBLE 28 __weak_alias(log2l, _log2l) 29 __strong_alias(_log2l, _log2) 30 #endif 31 32 __weak_alias(log2, _log2) 33 double 34 log2(double x) /* wrapper log10 */ 35 { 36 #ifdef _IEEE_LIBM 37 return __ieee754_log2(x); 38 #else 39 double z; 40 z = __ieee754_log2(x); 41 if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; 42 if(x<=0.0) { 43 if(x==0.0) 44 return __kernel_standard(x,x,48); /* log2(0) */ 45 else 46 return __kernel_standard(x,x,49); /* log2(x<0) */ 47 } else 48 return z; 49 #endif 50 } 51