From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [PATCH] Re: LLVM and PSEUDO_REG/PSEUDO_PHI Date: Sun, 28 Aug 2011 11:23:00 -0700 Message-ID: References: <4E58731A.7010708@garzik.org> <4E58AE9E.1090601@garzik.org> <4E59478C.9000504@garzik.org> <4E5A129F.1090801@garzik.org> <20110828175255.GA10203@leaf> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:48293 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750766Ab1H1SXW (ORCPT ); Sun, 28 Aug 2011 14:23:22 -0400 Received: from mail-wy0-f174.google.com (mail-wy0-f174.google.com [74.125.82.174]) (authenticated bits=0) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id p7SINKYD017583 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=FAIL) for ; Sun, 28 Aug 2011 11:23:21 -0700 Received: by wyg24 with SMTP id 24so3568975wyg.19 for ; Sun, 28 Aug 2011 11:23:20 -0700 (PDT) In-Reply-To: <20110828175255.GA10203@leaf> Sender: linux-sparse-owner@vger.kernel.org List-Id: linux-sparse@vger.kernel.org To: Josh Triplett Cc: Jeff Garzik , Pekka Enberg , Sparse Mailing-list On Sun, Aug 28, 2011 at 10:52 AM, Josh Triplett wrote: >> >> You should consider all types to be just "blocks of memory", and >> sparse has already calculated all offsets etc for you. As far as LLVM >> is concerned, the memory has no structure, it's just a blob. > > I suspect LLVM's optimization passes won't particularly care for that > approach. That's fine. We've already done the CSE and alias analysis on the thing. And as mentioned, trying to turn overlapping (or partial) accesses into some "named accesses" is just *wrong*. They weren't named in the C code either. They are accesses through pointer arithmetic. Trying to make them be somehow named would just be crazy. Linus