w_log10.c (984B)
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 #ifndef lint 14 static char rcsid[] = "$FreeBSD: src/lib/msun/src/w_log10.c,v 1.7 2002/05/28 18:15:04 alfred Exp $"; 15 #endif 16 17 /* 18 * wrapper log10(X) 19 */ 20 21 #include "math.h" 22 #include "math_private.h" 23 24 25 double 26 log10(double x) /* wrapper log10 */ 27 { 28 #ifdef _IEEE_LIBM 29 return __ieee754_log10(x); 30 #else 31 double z; 32 z = __ieee754_log10(x); 33 if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; 34 if(x<=0.0) { 35 if(x==0.0) 36 return __kernel_standard(x,x,18); /* log10(0) */ 37 else 38 return __kernel_standard(x,x,19); /* log10(x<0) */ 39 } else 40 return z; 41 #endif 42 }