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89 lines
1.8 KiB
C
89 lines
1.8 KiB
C
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/* @(#)w_sqrt.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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<<sqrt>>, <<sqrtf>>---positive square root
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INDEX
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sqrt
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INDEX
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sqrtf
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SYNOPSIS
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#include <math.h>
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double sqrt(double <[x]>);
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float sqrtf(float <[x]>);
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DESCRIPTION
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<<sqrt>> computes the positive square root of the argument.
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You can modify error handling for this function with
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<<matherr>>.
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RETURNS
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On success, the square root is returned. If <[x]> is real and
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positive, then the result is positive. If <[x]> is real and
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negative, the global value <<errno>> is set to <<EDOM>> (domain error).
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PORTABILITY
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<<sqrt>> is ANSI C. <<sqrtf>> is an extension.
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*/
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/*
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* wrapper sqrt(x)
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*/
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#include "fdlibm.h"
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#include <errno.h>
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#ifndef _DOUBLE_IS_32BITS
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#ifdef __STDC__
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double sqrt(double x) /* wrapper sqrt */
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#else
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double sqrt(x) /* wrapper sqrt */
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double x;
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#endif
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{
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#ifdef _IEEE_LIBM
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return __ieee754_sqrt(x);
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#else
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struct exception exc;
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double z;
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z = __ieee754_sqrt(x);
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if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
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if(x<0.0) {
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exc.type = DOMAIN;
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exc.name = "sqrt";
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exc.err = 0;
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exc.arg1 = exc.arg2 = x;
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if (_LIB_VERSION == _SVID_)
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exc.retval = 0.0;
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else
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exc.retval = 0.0/0.0;
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if (_LIB_VERSION == _POSIX_)
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errno = EDOM;
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else if (!matherr(&exc)) {
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errno = EDOM;
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}
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if (exc.err != 0)
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errno = exc.err;
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return exc.retval;
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} else
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return z;
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#endif
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}
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#endif /* defined(_DOUBLE_IS_32BITS) */
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