From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 36111 invoked by alias); 26 Jul 2017 19:16:16 -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 35868 invoked by uid 89); 26 Jul 2017 19:16:05 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 26 Jul 2017 19:15:52 +0000 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CEF48552F6; Wed, 26 Jul 2017 19:15:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com CEF48552F6 Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=law@redhat.com Received: from localhost.localdomain (ovpn-116-95.phx2.redhat.com [10.3.116.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 88DD560472; Wed, 26 Jul 2017 19:15:50 +0000 (UTC) Subject: Re: [PATCH][AArch64] Simplify frame layout for stack probing To: Wilco Dijkstra , GCC Patches , James Greenhalgh Cc: nd References: From: Jeff Law Message-ID: <2346b545-8740-a861-2855-14d5e81bb75e@redhat.com> Date: Wed, 26 Jul 2017 19:16:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2017-07/txt/msg01720.txt.bz2 On 07/25/2017 07:58 AM, Wilco Dijkstra wrote: > This patch makes some changes to the frame layout in order to simplify > stack probing. We want to use the save of LR as a probe in any non-leaf > function. With shrinkwrapping we may only save LR before a call, so it > is useful to define a fixed location in the callee-saves. So force LR at > the bottom of the callee-saves even with -fomit-frame-pointer. > > Also remove a rarely used frame layout that saves the callee-saves first > with -fomit-frame-pointer. > > OK for commit (and backport to GCC7)? > > ChangeLog: > 2017-07-25 Wilco Dijkstra > > * config/aarch64/aarch64.c (aarch64_layout_frame): > Ensure LR is always stored at the bottom of the callee-saves. > Remove frame option which saves callee-saves at top of frame. I'll let the appropriate aarch64 maintainers comment on correctness. But I wanted to give an explicit thanks for simplifying this so that we can rely on it. Jeff