From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 40C1DC433EF for ; Fri, 15 Jul 2022 14:39:29 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LkvBl3MB7z3cgf for ; Sat, 16 Jul 2022 00:39:27 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.crashing.org (client-ip=63.228.1.57; helo=gate.crashing.org; envelope-from=segher@kernel.crashing.org; receiver=) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) by lists.ozlabs.org (Postfix) with ESMTP id 4LkvBH5TCCz3c5p for ; Sat, 16 Jul 2022 00:39:02 +1000 (AEST) Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 26FEZtii021186; Fri, 15 Jul 2022 09:35:55 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 26FEZshl021184; Fri, 15 Jul 2022 09:35:54 -0500 X-Authentication-Warning: gate.crashing.org: segher set sender to segher@kernel.crashing.org using -f Date: Fri, 15 Jul 2022 09:35:54 -0500 From: Segher Boessenkool To: Nicholas Piggin Subject: Re: [PATCH Linux] powerpc: add documentation for HWCAPs Message-ID: <20220715143554.GY25951@gate.crashing.org> References: <20220524093828.505575-1-npiggin@gmail.com> <87ee0juukf.fsf@oldenburg.str.redhat.com> <20220524183236.GJ25951@gate.crashing.org> <1657846871.9qtz2ahf6c.astroid@bobo.none> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1657846871.9qtz2ahf6c.astroid@bobo.none> User-Agent: Mutt/1.4.2.3i X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Florian Weimer , gcc@gcc.gnu.org, libc-alpha@sourceware.org, linuxppc-dev@lists.ozlabs.org, Paul E Murphy Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, Jul 15, 2022 at 11:17:24AM +1000, Nicholas Piggin wrote: > Excerpts from Segher Boessenkool's message of May 25, 2022 4:32 am: > > Linux runs on ISA 1.xx and ISA 2.01 machines still. "Category" wasn't > > invented for either yet either, but similar concepts did exist of > > course. > > Not sure what to say about this. It now also has "Compliancy Subset" > although maybe that's more like a set of features rather than > incompatible features or modes such as some of the category stuff > seems to be. I'll try add something. The compliancy subset stuff is an attempt to simplify things again. In most cases you want to require a whole swath of feature at once, if you really try to support fine-grained optional features you need to test thousands of configurations, while you really can test only ten (if you are lucky!) Maybe it is best to just be a bit vague here? Segher