5980be9b3c
This work is based in part on code from NetBSD libm, libc and kernel. The library is partly public domain and partly BSD-style licensed.
52 lines
1.2 KiB
C
52 lines
1.2 KiB
C
/* @(#)w_exp.c 5.1 93/09/24 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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#include <sys/cdefs.h>
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#if defined(LIBM_SCCS) && !defined(lint)
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__RCSID("$NetBSD: w_exp.c,v 1.10 2007/08/20 16:01:40 drochner Exp $");
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#endif
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/*
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* wrapper exp(x)
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*/
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#include "namespace.h"
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#include "math.h"
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#include "math_private.h"
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#ifdef __weak_alias
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__weak_alias(exp, _exp)
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#endif
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static const double
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o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */
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u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */
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double
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exp(double x) /* wrapper exp */
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{
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#ifdef _IEEE_LIBM
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return __ieee754_exp(x);
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#else
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double z;
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z = __ieee754_exp(x);
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if(_LIB_VERSION == _IEEE_) return z;
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if(finite(x)) {
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if(x>o_threshold)
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return __kernel_standard(x,x,6); /* exp overflow */
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else if(x<u_threshold)
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return __kernel_standard(x,x,7); /* exp underflow */
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}
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return z;
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#endif
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}
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