Return-Path: thread-index: AcQVpP7rXz6ChwS6TS2gk1fytqlIpg== Envelope-to: paul@sumlocktest.fsnet.co.uk Delivery-date: Tue, 06 Jan 2004 06:08:23 +0000 Message-ID: <049201c415a4$feebc2a0$d100000a@sbs2003.local> Content-Transfer-Encoding: 7bit X-Mailer: Microsoft CDO for Exchange 2000 Content-Class: urn:content-classes:message Importance: normal Priority: normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.0 Date: Mon, 29 Mar 2004 16:46:26 +0100 From: "Jakob Oestergaard" To: Cc: "Mikael Pettersson" , , Subject: Re: Pentium M config option for 2.6 Mail-Followup-To: Jakob Oestergaard , Tomas Szepe , Mikael Pettersson , akpm@osdl.org, linux-kernel@vger.kernel.org References: <200401041227.i04CReNI004912@harpo.it.uu.se> <20040104123358.GB24913@louise.pinerecords.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20040104123358.GB24913@louise.pinerecords.com> User-Agent: Mutt/1.3.28i Sender: X-Mailing-List: linux-kernel@vger.kernel.org X-OriginalArrivalTime: 29 Mar 2004 15:46:29.0171 (UTC) FILETIME=[0047D030:01C415A5] On Sun, Jan 04, 2004 at 01:33:58PM +0100, Tomas Szepe wrote: > On Jan-04 2004, Sun, 13:27 +0100 > Mikael Pettersson wrote: > > > IOW, don't lie to the compiler and pretend P-M == P4 > > with that -march=pentium4. > > What do you recommend to use as march then? There is > no pentiumm subarch support in gcc yet; I was convinced > p4 was the closest match. Use the same as for P-III. The P-M has the same instruction decoder (and execution unit) setup as the P-III, which is *very* different from P-IV (which has one decoder only, and then a trace cache for the decoded uops). This is an important difference from a code generator point of view. >From reading Intel's optimization guides, it seems to me like the P-M is pretty much just a slightly enhanced P-III (more cache AFAIR) which happens to get shipped with a good mobile chipset - and that package together is called Centrino. That would also explain why Centrino leaves the P-IV based laptops in the dust ;) Cheers, / jakob - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/