0,0 → 1,93 |
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/* @(#)w_sqrt.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. |
* ==================================================== |
*/ |
|
/* |
FUNCTION |
<<sqrt>>, <<sqrtf>>---positive square root |
|
INDEX |
sqrt |
INDEX |
sqrtf |
|
ANSI_SYNOPSIS |
#include <math.h> |
double sqrt(double <[x]>); |
float sqrtf(float <[x]>); |
|
TRAD_SYNOPSIS |
#include <math.h> |
double sqrt(<[x]>); |
float sqrtf(<[x]>); |
|
DESCRIPTION |
<<sqrt>> computes the positive square root of the argument. |
You can modify error handling for this function with |
<<matherr>>. |
|
RETURNS |
On success, the square root is returned. If <[x]> is real and |
positive, then the result is positive. If <[x]> is real and |
negative, the global value <<errno>> is set to <<EDOM>> (domain error). |
|
|
PORTABILITY |
<<sqrt>> is ANSI C. <<sqrtf>> is an extension. |
*/ |
|
/* |
* wrapper sqrt(x) |
*/ |
|
#include "fdlibm.h" |
#include <errno.h> |
|
#ifndef _DOUBLE_IS_32BITS |
|
#ifdef __STDC__ |
double sqrt(double x) /* wrapper sqrt */ |
#else |
double sqrt(x) /* wrapper sqrt */ |
double x; |
#endif |
{ |
#ifdef _IEEE_LIBM |
return __ieee754_sqrt(x); |
#else |
struct exception exc; |
double z; |
z = __ieee754_sqrt(x); |
if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; |
if(x<0.0) { |
exc.type = DOMAIN; |
exc.name = "sqrt"; |
exc.err = 0; |
exc.arg1 = exc.arg2 = x; |
if (_LIB_VERSION == _SVID_) |
exc.retval = 0.0; |
else |
exc.retval = 0.0/0.0; |
if (_LIB_VERSION == _POSIX_) |
errno = EDOM; |
else if (!matherr(&exc)) { |
errno = EDOM; |
} |
if (exc.err != 0) |
errno = exc.err; |
return exc.retval; |
} else |
return z; |
#endif |
} |
|
#endif /* defined(_DOUBLE_IS_32BITS) */ |