/* @(#)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) */