w_scalb.c (1294B)
1 /* @(#)w_scalb.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_scalb.c,v 1.7 2002/05/28 18:15:04 alfred Exp $"; 15 #endif 16 17 /* 18 * wrapper scalb(double x, double fn) is provide for 19 * passing various standard test suite. One 20 * should use scalbn() instead. 21 */ 22 23 #include "math.h" 24 #include "math_private.h" 25 26 #include <errno.h> 27 28 #ifdef _SCALB_INT 29 double 30 scalb(double x, int fn) /* wrapper scalb */ 31 #else 32 double 33 scalb(double x, double fn) /* wrapper scalb */ 34 #endif 35 { 36 #ifdef _IEEE_LIBM 37 return __ieee754_scalb(x,fn); 38 #else 39 double z; 40 z = __ieee754_scalb(x,fn); 41 if(_LIB_VERSION == _IEEE_) return z; 42 if(!(finite(z)||isnan(z))&&finite(x)) { 43 return __kernel_standard(x,(double)fn,32); /* scalb overflow */ 44 } 45 if(z==0.0&&z!=x) { 46 return __kernel_standard(x,(double)fn,33); /* scalb underflow */ 47 } 48 #ifndef _SCALB_INT 49 if(!finite(fn)) errno = ERANGE; 50 #endif 51 return z; 52 #endif 53 }