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| 2 | /* @(#)w_sqrt.c 5.1 93/09/24 */
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| 3 | /*
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| 4 | * ====================================================
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| 5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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| 6 | *
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| 7 | * Developed at SunPro, a Sun Microsystems, Inc. business.
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| 8 | * Permission to use, copy, modify, and distribute this
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| 9 | * software is freely granted, provided that this notice
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| 10 | * is preserved.
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| 11 | * ====================================================
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| 12 | */
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| 13 |
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| 14 | /*
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| 15 | FUNCTION
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| 16 | <<sqrt>>, <<sqrtf>>---positive square root
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| 17 |
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| 18 | INDEX
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| 19 | sqrt
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| 20 | INDEX
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| 21 | sqrtf
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| 22 |
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| 23 | ANSI_SYNOPSIS
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| 24 | #include <math.h>
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| 25 | double sqrt(double <[x]>);
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| 26 | float sqrtf(float <[x]>);
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| 27 |
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| 28 | TRAD_SYNOPSIS
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| 29 | #include <math.h>
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| 30 | double sqrt(<[x]>);
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| 31 | float sqrtf(<[x]>);
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| 32 |
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| 33 | DESCRIPTION
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| 34 | <<sqrt>> computes the positive square root of the argument.
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| 35 | You can modify error handling for this function with
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| 36 | <<matherr>>.
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| 37 |
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| 38 | RETURNS
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| 39 | On success, the square root is returned. If <[x]> is real and
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| 40 | positive, then the result is positive. If <[x]> is real and
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| 41 | negative, the global value <<errno>> is set to <<EDOM>> (domain error).
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| 42 |
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| 43 |
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| 44 | PORTABILITY
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| 45 | <<sqrt>> is ANSI C. <<sqrtf>> is an extension.
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| 46 | */
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| 47 |
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| 48 | /*
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| 49 | * wrapper sqrt(x)
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| 50 | */
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| 51 |
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| 52 | #include "fdlibm.h"
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| 53 | #include <errno.h>
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| 54 |
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| 55 | #ifndef _DOUBLE_IS_32BITS
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| 56 |
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| 57 | #ifdef __STDC__
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| 58 | double sqrt(double x) /* wrapper sqrt */
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| 59 | #else
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| 60 | double sqrt(x) /* wrapper sqrt */
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| 61 | double x;
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| 62 | #endif
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| 63 | {
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| 64 | #ifdef _IEEE_LIBM
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| 65 | return __ieee754_sqrt(x);
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| 66 | #else
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| 67 | struct exception exc;
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| 68 | double z;
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| 69 | z = __ieee754_sqrt(x);
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| 70 | if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
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| 71 | if(x<0.0) {
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| 72 | exc.type = DOMAIN;
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| 73 | exc.name = "sqrt";
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| 74 | exc.err = 0;
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| 75 | exc.arg1 = exc.arg2 = x;
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| 76 | if (_LIB_VERSION == _SVID_)
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| 77 | exc.retval = 0.0;
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| 78 | else
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| 79 | exc.retval = 0.0/0.0;
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| 80 | if (_LIB_VERSION == _POSIX_)
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| 81 | errno = EDOM;
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| 82 | else if (!matherr(&exc)) {
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| 83 | errno = EDOM;
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| 84 | }
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| 85 | if (exc.err != 0)
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| 86 | errno = exc.err;
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| 87 | return exc.retval;
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| 88 | } else
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| 89 | return z;
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| 90 | #endif
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| 91 | }
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| 92 |
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| 93 | #endif /* defined(_DOUBLE_IS_32BITS) */
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