From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268069AbUHVTRd (ORCPT ); Sun, 22 Aug 2004 15:17:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268073AbUHVTRd (ORCPT ); Sun, 22 Aug 2004 15:17:33 -0400 Received: from darwin.snarc.org ([81.56.210.228]:4816 "EHLO darwin.snarc.org") by vger.kernel.org with ESMTP id S268069AbUHVTRa (ORCPT ); Sun, 22 Aug 2004 15:17:30 -0400 Date: Sun, 22 Aug 2004 21:17:27 +0200 To: Albert Cahalan Cc: benh@kernel.crashing.org, linux-kernel mailing list Subject: Re: [PATCH] ppc32 use simplified mmenonics Message-ID: <20040822191727.GB12014@snarc.org> References: <1093135526.5759.2513.camel@cube> <20040822094317.GA2589@snarc.org> <1093171291.5759.2544.camel@cube> <20040822144501.GA10017@snarc.org> <1093178422.2301.2674.camel@cube> <20040822162845.GA10911@snarc.org> <1093184939.2301.2799.camel@cube> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1093184939.2301.2799.camel@cube> X-Warning: Email may contain unsmilyfied humor and/or satire. User-Agent: Mutt/1.5.6+20040803i From: Vincent Hanquez Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 22, 2004 at 10:29:00AM -0400, Albert Cahalan wrote: > That comes to 2304. Subtract the 456 "simplified" > instruction names you have. That leaves 1848 that > you are unable to access. > > Take a look at the crand instruction. It uses numbers. > Now, just imagine mixing that with branch instructions > that hide the numbers. I hope you see the problem. I never said we should use simplified instructions everywhere there are instructions. Hence I don't see why we care here about 1848 instructions not beeing accessible. Most of thoses 1848 instructions probably fit in the 'not so much' used, and thus doesn't need a simplified mmenonic. > It doesn't appear to be so. He wrote: > > : Oh well.. I've got quite used to tweaking rlwinm directly > : but I suppose it's more clear for others to go to clrrwi. > > So I'd like him to know that others like rlwinm directly too. sure. and some other prefer simplified instructions. I guess we're hitting a wall here :) But as clrrwi is already use in the kernel (as a lot of others simplified instructions), either send a patch to remove them or don't say that this is madness. > Using instructions that are in the index makes sense. > Using a zillion poorly documented alternatives is madness. Maybe then you should rewrite all part of kernels, gcc, objdump and gdb that use/disassemble the code with simplified instructions (mr, li, b*, etc...) too. (clrrwi is as documented as mr) -- Tab