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Diffstat (limited to 'libm/w_exp.c')
-rw-r--r-- | libm/w_exp.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/libm/w_exp.c b/libm/w_exp.c new file mode 100644 index 000000000..81a6bf702 --- /dev/null +++ b/libm/w_exp.c @@ -0,0 +1,53 @@ +/* @(#)w_exp.c 5.1 93/09/24 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#if defined(LIBM_SCCS) && !defined(lint) +static char rcsid[] = "$NetBSD: w_exp.c,v 1.6 1995/05/10 20:48:51 jtc Exp $"; +#endif + +/* + * wrapper exp(x) + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ +static const double +#else +static double +#endif +o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */ +u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */ + +#ifdef __STDC__ + double exp(double x) /* wrapper exp */ +#else + double exp(x) /* wrapper exp */ + double x; +#endif +{ +#ifdef _IEEE_LIBM + return __ieee754_exp(x); +#else + double z; + z = __ieee754_exp(x); + if(_LIB_VERSION == _IEEE_) return z; + if(finite(x)) { + if(x>o_threshold) + return __kernel_standard(x,x,6); /* exp overflow */ + else if(x<u_threshold) + return __kernel_standard(x,x,7); /* exp underflow */ + } + return z; +#endif +} |