On 2006-12-21 17:42:15 -0500, Robert Dewar wrote: > Marcin Dalecki wrote: > > >Of course I didn't think about a substitute for ==. Not! However I think > >that checks for |x-y| < epsilion, could be really given a significant > >speed edge > >if done in a single go in hardware. > > One thing to ponder here is that "thinks" like this are what lead > to CISC instruction messes. It just seems obvious to people that > it will help efficiency to have highly specialized instructions, > but in practice they gum up the architecture with junk, and a > careful analysis shows that the actual gain is small at best. > How many applications spend a significant amount of time doing > such an epsilon test -- best guess: none.
Indeed, no-one has requested for one in the revision of IEEE 754, AFAIK. -- Vincent Lefèvre <[EMAIL PROTECTED]> - Web: <http://www.vinc17.org/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/> Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon)
