71 lines
1.4 KiB
C
71 lines
1.4 KiB
C
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/* @(#)w_exp2.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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/*
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FUNCTION
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<<exp2>>, <<exp2f>>--exponential, base 2
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INDEX
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exp2
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INDEX
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exp2f
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ANSI_SYNOPSIS
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#include <math.h>
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double exp2(double <[x]>);
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float exp2f(float <[x]>);
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DESCRIPTION
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<<exp2>> and <<exp2f>> calculate 2 ^ <[x]>, that is,
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@ifnottex
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2 raised to the power <[x]>.
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@end ifnottex
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@tex
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$2^x$
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@end tex
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You can use the (non-ANSI) function <<matherr>> to specify
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error handling for these functions.
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RETURNS
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On success, <<exp2>> and <<exp2f>> return the calculated value.
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If the result underflows, the returned value is <<0>>. If the
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result overflows, the returned value is <<HUGE_VAL>>. In
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either case, <<errno>> is set to <<ERANGE>>.
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PORTABILITY
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ANSI C, POSIX.
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*/
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/*
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* wrapper exp2(x)
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*/
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#include "fdlibm.h"
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#include <errno.h>
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#include <math.h>
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#ifndef _DOUBLE_IS_32BITS
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#ifdef __STDC__
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double exp2(double x) /* wrapper exp2 */
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#else
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double exp2(x) /* wrapper exp2 */
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double x;
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#endif
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{
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return pow(2.0, x);
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}
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#endif /* defined(_DOUBLE_IS_32BITS) */
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