Date: Wed, 26 Jan 2000 11:43:02 +0100 (CET) From: Martin Ockajak <mandos AT hq DOT alert DOT sk> To: pgcc AT delorie DOT com Subject: Re: pgcc on AMD K6 In-Reply-To: <Pine.LNX.4.21.0001141830350.4315-100000@hq.alert.sk> Message-ID: <Pine.LNX.4.21.0001261105090.26171-100000@hq.alert.sk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: pgcc AT delorie DOT com Errors-To: dj-admin AT delorie DOT com X-Mailing-List: pgcc AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Fri, 14 Jan 2000, Robert Varga wrote: > > Check the Makefile, if there are any refs to -mpentiumpro, (which I did see, though I think that's supposed to only enable the scheduling for Pentium Pro), > > -march=pentiumpro or -march=i686, change them to -march=k6. Also, don't use i686 ASM, which may also contain Pentium Pro specific opcodes. K6 doesn't support cmove, but > > AMD Athlon does (I just checked mine, and WCPUID says it does) > > K6-2 tests show that more optimal combination would be > -march=pentium -mcpu=pentiumpro yes, it seems that current PPro machine desc. matches K6-2 better than K6 description one of the reasons is IMHO unrealistic K6 branch costs model but there are others too i wrote some support for K6-2/3 and it seems to be promising but i'm not satisfied with the performance yet and of course i have to test it some more i'll send it then this brings me the question: Should the K6-2/3 support be apart from K6 support (so we would have -mcpu=k62 and -mcpu=k6) or should it be just generic K6 support (as currently is) but aimed mostly on K6-2/3 (well, K6 an K6-2/3 are different but not "very" different) any suggestions ? > don't really know about the K-3. well, according to K6-3 specs K6-3 is nothing more than K6-2 plus 256KB L2 cache which makes difference in overall performance but doesn't make difference in insns scheduling at all - ------------------------------------------------------------------------------ Martin Ockajak a.k.a. Mandos <mandos AT hq DOT alert DOT sk> http://hq.alert.sk/~mandos "The goal of Computer Science is to build something that will last at least until we've finished building it." -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.0 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE4js+404YFujOC4BMRApIeAJ4rAGSIit2xtz7GxfY1skxnzp0OHgCfer2u Pv1ckRiGJsIrsmH3ydfIuY0= =5DIf -----END PGP SIGNATURE-----