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 1.7 2007/08/20 16:01:40 drochner Exp $"); 19 #endif 20 21 /* 22 * wrapper expf(x) 23 */ 24 25 #include "namespace.h" 26 #include "math.h" 27 #include "math_private.h" 28 29 #ifdef __weak_alias 30 __weak_alias(expf, _expf) 31 #endif 32 33 static const float 34 o_threshold= 8.8721679688e+01, /* 0x42b17180 */ 35 u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */ 36 37 float 38 expf(float x) /* wrapper expf */ 39 { 40 #ifdef _IEEE_LIBM 41 return __ieee754_expf(x); 42 #else 43 float z; 44 z = __ieee754_expf(x); 45 if(_LIB_VERSION == _IEEE_) return z; 46 if(finitef(x)) { 47 if(x>o_threshold) 48 /* exp overflow */ 49 return (float)__kernel_standard((double)x,(double)x,106); 50 else if(x<u_threshold) 51 /* exp underflow */ 52 return (float)__kernel_standard((double)x,(double)x,107); 53 } 54 return z; 55 #endif 56 } 57