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 #if defined(LIBM_SCCS) && !defined(lint) 17 static char rcsid[] = "$NetBSD: w_expf.c,v 1.3 1995/05/10 20:48:53 jtc Exp $"; 18 #endif 19 20 /* 21 * wrapper expf(x) 22 */ 23 24 #include "math.h" 25 #include "math_private.h" 26 27 #ifdef __STDC__ 28 static const float 29 #else 30 static float 31 #endif 32 o_threshold= 8.8721679688e+01, /* 0x42b17180 */ 33 u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */ 34 35 #ifdef __STDC__ 36 float expf(float x) /* wrapper expf */ 37 #else 38 float expf(x) /* wrapper expf */ 39 float x; 40 #endif 41 { 42 #ifdef _IEEE_LIBM 43 return __ieee754_expf(x); 44 #else 45 float z; 46 z = __ieee754_expf(x); 47 if(_LIB_VERSION == _IEEE_) return z; 48 if(finitef(x)) { 49 if(x>o_threshold) 50 /* exp overflow */ 51 return (float)__kernel_standard((double)x,(double)x,106); 52 else if(x<u_threshold) 53 /* exp underflow */ 54 return (float)__kernel_standard((double)x,(double)x,107); 55 } 56 return z; 57 #endif 58 } 59