On Fri, 2011-12-16 at 10:09 +0100, Richard Herveille wrote: > What would the benefit of this be?? You get one additional register, > but it breaks the entire way the OR is setup (R0 being a '0' > register). > I don't think having 1 extra register outweighs the disadvantages.
I'm not saying it is a bad thing at all. If I were designing the architecture from scratch I would hard wire r0 to '0' since it is so useful. However it is an incompatible change, because future code will not be sure to work on older machines. So for example Samsung would not be able to use the new compiler and libraries on their current range of DTV chips. It is precisely because it is such a useful change that is dangerous. Loads of code (including the compiler) will take advantage of it, and that code will almost certainly break on old chips. If we want OpenRISC to be credible, obsoleting all existing designs at a stroke is not a good plan! Jeremy -- Tel: +44 (1590) 610184 Cell: +44 (7970) 676050 SkypeID: jeremybennett Email: [email protected] Web: www.embecosm.com _______________________________________________ OpenRISC mailing list [email protected] http://lists.openrisc.net/listinfo/openrisc
