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 1.4 1997/10/09 11:34:39 lukem Exp $"); 19 #endif 20 21 /* 22 * wrapper expf(x) 23 */ 24 25 #include "math.h" 26 #include "math_private.h" 27 28 #ifdef __STDC__ 29 static const float 30 #else 31 static float 32 #endif 33 o_threshold= 8.8721679688e+01, /* 0x42b17180 */ 34 u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */ 35 36 #ifdef __STDC__ 37 float expf(float x) /* wrapper expf */ 38 #else 39 float expf(x) /* wrapper expf */ 40 float x; 41 #endif 42 { 43 #ifdef _IEEE_LIBM 44 return __ieee754_expf(x); 45 #else 46 float z; 47 z = __ieee754_expf(x); 48 if(_LIB_VERSION == _IEEE_) return z; 49 if(finitef(x)) { 50 if(x>o_threshold) 51 /* exp overflow */ 52 return (float)__kernel_standard((double)x,(double)x,106); 53 else if(x<u_threshold) 54 /* exp underflow */ 55 return (float)__kernel_standard((double)x,(double)x,107); 56 } 57 return z; 58 #endif 59 } 60