From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5609 invoked by alias); 9 Sep 2016 21:00:25 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 5548 invoked by uid 89); 9 Sep 2016 21:00:21 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.1 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: gate.crashing.org Received: from gate.crashing.org (HELO gate.crashing.org) (63.228.1.57) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 09 Sep 2016 21:00:01 +0000 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.13.8) with ESMTP id u89KxtJK026353; Fri, 9 Sep 2016 15:59:56 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id u89KxseI026342; Fri, 9 Sep 2016 15:59:54 -0500 Date: Fri, 09 Sep 2016 21:05:00 -0000 From: Segher Boessenkool To: Jeff Law Cc: gcc-patches@gcc.gnu.org, bschmidt@redhat.com Subject: Re: [PATCH 4/9] regrename: Don't rename restores Message-ID: <20160909205953.GE21356@gate.crashing.org> References: <3d1c2c877df1da0be9eca7cb1016e8b7a7d287c8.1470015604.git.segher@kernel.crashing.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-IsSubscribed: yes X-SW-Source: 2016-09/txt/msg00544.txt.bz2 On Thu, Sep 08, 2016 at 11:51:53AM -0600, Jeff Law wrote: > On 07/31/2016 07:42 PM, Segher Boessenkool wrote: > >A restore is supposed to restore some certain register. Restoring it > >into some other register will not work. Don't. > > > >2016-06-07 Segher Boessenkool > > > > * regrename.c (build_def_use): Invalidate chains that have a > > REG_CFA_RESTORE on some instruction. > Again, how is this different from a normal epilogue that restores > registers which regrename seems to not muck with. Good question. Either way, it is always wrong to rename a register we restore from stack. Segher