1 /* w_expf.c -- float version of w_exp.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_expf.c,v 1.6 2002/05/26 22:02:00 wiz Exp $"); 19 #endif 20 21 /* 22 * wrapper expf(x) 23 */ 24 25 #include "math.h" 26 #include "math_private.h" 27 28 static const float 29 o_threshold= 8.8721679688e+01, /* 0x42b17180 */ 30 u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */ 31 32 float 33 expf(float x) /* wrapper expf */ 34 { 35 #ifdef _IEEE_LIBM 36 return __ieee754_expf(x); 37 #else 38 float z; 39 z = __ieee754_expf(x); 40 if(_LIB_VERSION == _IEEE_) return z; 41 if(finitef(x)) { 42 if(x>o_threshold) 43 /* exp overflow */ 44 return (float)__kernel_standard((double)x,(double)x,106); 45 else if(x<u_threshold) 46 /* exp underflow */ 47 return (float)__kernel_standard((double)x,(double)x,107); 48 } 49 return z; 50 #endif 51 } 52