On Oct 16, 2009, at 2:51 PM, nathan binkert wrote: >> I'm sure Tim knows best wherher he's implemented POWER or PowerPC... >> If it is the latter, I'd favor using PPC for naming just to keep >> things brief. > > I'm not totally familiar with the naming, but isn't POWER the superset > of it all? I guess the real question is, if tim really did just ppc > and someone were going to actually do power, would they do it in the > same directory or not. If it is the same, then power seems the right > name. If not, probably ppc.
The POWER and PowerPC ISAs used to be slightly different, with neither being a true superset of the other: While PowerPC was based on POWER (the architecture of the initial IBM RS/6000 machines), it included some additional features and instructions and removed others; also, there were some subsequent extensions to POWER that never made it into PowerPC. Older versions of the PowerPC ISA actually used to have an appendix detailing the differences, but that seems to have been removed from the current one. It should be noted, however, that POWER3 (the processor) and up actually implement the 64-bit PowerPC ISA (with IBM's proprietary PowerPC AS extensions), so POWER (the ISA) is really only of historical interest by now. To further add to the confusion, the PowerPC 2.02 ISA was recently (2006) merged with the "Book E" embedded variant of the architecture developed by Freescale to form what is now (as of version 2.03 and up) officially known as the "Power ISA" (note capitalization), with -S and -E variants for servers and the embedded space, respectively. In short, "power" would indeed be the more appropriate name. Daniel _______________________________________________ m5-dev mailing list m5-dev@m5sim.org http://m5sim.org/mailman/listinfo/m5-dev
