| |
| /* @(#)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) */ |
