Floating point comparisons should _always_ be done via a confidence interval, not bitwise equality. As for determinism, I don't know what the logic circuits look like, so can't and won't comment :}.
Rob > -----Original Message----- > From: Chuck Allison [mailto:[EMAIL PROTECTED]] > Sent: Monday, March 04, 2002 4:08 PM > To: Richard R. Malloy; Randall R Schulz > Cc: Ross Smith; [EMAIL PROTECTED] > Subject: Re: Strange behavior > > > That's the point. They're always redued, so in both cases, > the expression 2.0/3.0 is evaluated. How can that be > non-deterministic? > > ----- Original Message ----- > From: "Richard R. Malloy" <[EMAIL PROTECTED]> > To: "Randall R Schulz" <[EMAIL PROTECTED]> > Cc: "Ross Smith" <[EMAIL PROTECTED]>; "'Chuck Allison'" > <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > Sent: Sunday, March 03, 2002 9:47 PM > Subject: Re: Strange behavior > > > > OK. I'm no IA32 expert can someone explain the following > results. (Do > > the floating point registers use guard bits, randomly initialized > > perhaps?) > > > > bool operator==(const Rational& r1, const Rational& r2) > > { > > double a=r1.toDouble(), b=r2.toDouble(); > > cout << ?== a " << a << " " << ?== b " << b << endl; > > return a == b; > > // return r1.toDouble() == r2.toDouble(); > > /* return ( r1.numerator == r2.numerator && r1.denominator == > > r2.denominator ); */ } -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
