From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-in-07.arcor-online.net (mail-in-07.arcor-online.net [151.189.21.47]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.arcor.de", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 723EF67A73 for ; Sun, 30 Apr 2006 13:13:14 +1000 (EST) In-Reply-To: <17491.64254.653743.367039@cargo.ozlabs.ibm.com> References: <17491.1134.565353.149941@cargo.ozlabs.ibm.com> <20060429151936.GM5518@pb15.lixom.net> <17491.64254.653743.367039@cargo.ozlabs.ibm.com> Mime-Version: 1.0 (Apple Message framework v749.3) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <71339D1F-CAF1-4FF0-A1A3-1A74B8984F05@kernel.crashing.org> From: Segher Boessenkool Subject: Re: please pull powerpc.git 'merge' branch Date: Sun, 30 Apr 2006 05:12:57 +0200 To: Paul Mackerras Cc: Olof Johansson , linuxppc-dev@ozlabs.org, torvalds@osdl.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >> Previously we've said implementation instead of specification >> ("PPC_FEATURE_POWER5_PLUS" etc). That's better than saying base >> architecture version, since there are parts of the arch that might or >> might not be implemented (i.e. optional features, etc). > > We now have the AT_PLATFORM string, which we didn't have when we added > the POWER5_PLUS etc. features. That specifies which particular > implementation we are on quite precisely. We don't want to have a bit > for every single implementation or we'll run out of bits. > > The ARCH_2_05 bit means all the non-optional bits of the 2.05 > architecture. If there are optional features in the architecture, we > have separate bits for them. For example, we don't have separate > bits for POWER4 and for 970; instead we have a HAS_ALTIVEC bit, and > for 970 we set both POWER4 and HAS_ALTIVEC. So the POWER4 bit is > really a "2.00 architecture version" bit. Except that the 970 at least is actually version 2.01. Sounds like names are better than bare numbers -- you showed yourself that numbers like this are confusing, but you also say that a cpu name really means an arch version (which isn't so bad -- there generally is only one "main" CPU per arch version anyway, and people generally know what is compatible to what). So please rename ARCH_2_05 to the name of the first CPU that implements architecture 2.05? Segher