1 /* wf_exp.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 /* 17 * wrapper expf(x) 18 */ 19 20 #include "fdlibm.h" 21 #if __OBSOLETE_MATH 22 #include <errno.h> 23 24 #if !defined(_IEEE_LIBM) || !defined(HAVE_ALIAS_ATTRIBUTE) 25 #ifdef __STDC__ 26 static const float 27 #else 28 static float 29 #endif 30 o_threshold= 8.8721679688e+01, /* 0x42b17180 */ 31 u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */ 32 33 #ifdef __STDC__ expf(float x)34 float expf(float x) /* wrapper expf */ 35 #else 36 float expf(x) /* wrapper expf */ 37 float x; 38 #endif 39 { 40 float z; 41 z = __ieee754_expf(x); 42 if(_LIB_VERSION == _IEEE_) return z; 43 if(finitef(x)) { 44 if(x>o_threshold) { 45 /* expf(finite) overflow */ 46 errno = ERANGE; 47 return HUGE_VALF; 48 } else if(x<u_threshold) { 49 /* expf(finite) underflow */ 50 errno = ERANGE; 51 return 0.0f; 52 } 53 } 54 return z; 55 } 56 #endif 57 58 #ifdef _DOUBLE_IS_32BITS 59 60 #ifdef __STDC__ exp(double x)61 double exp(double x) 62 #else 63 double exp(x) 64 double x; 65 #endif 66 { 67 return (double) expf((float) x); 68 } 69 70 #endif /* defined(_DOUBLE_IS_32BITS) */ 71 #endif /* __OBSOLETE_MATH */ 72