From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 92633 invoked by alias); 6 Oct 2015 15:30:24 -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 92585 invoked by uid 89); 6 Oct 2015 15:30:20 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mailapp01.imgtec.com Received: from mailapp01.imgtec.com (HELO mailapp01.imgtec.com) (195.59.15.196) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 06 Oct 2015 15:30:19 +0000 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id 1C6DED41F99CB; Tue, 6 Oct 2015 16:30:08 +0100 (IST) Received: from BAMAIL02.ba.imgtec.org (10.20.40.28) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.195.1; Tue, 6 Oct 2015 16:30:11 +0100 Received: from [10.20.3.58] (10.20.3.58) by bamail02.ba.imgtec.org (10.20.40.28) with Microsoft SMTP Server (TLS) id 14.3.174.1; Tue, 6 Oct 2015 08:30:09 -0700 Message-ID: <1444145408.8687.238.camel@ubuntu-sellcey> Subject: Re: RFC: Patch to allow spill slot alignment greater than the stack alignment From: Steve Ellcey Reply-To: To: "H.J. Lu" CC: Bernd Schmidt , GCC Patches Date: Tue, 06 Oct 2015 15:30:00 -0000 In-Reply-To: References: <1443819469.8687.182.camel@ubuntu-sellcey> <561237B9.1080602@redhat.com> <1444061411.8687.207.camel@ubuntu-sellcey> <1444063572.8687.219.camel@ubuntu-sellcey> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-SW-Source: 2015-10/txt/msg00586.txt.bz2 On Mon, 2015-10-05 at 09:57 -0700, H.J. Lu wrote: > You need to update dwarf2cfi.c to generate proper unwind info for > whatever frame instructions MIPS generates, like what we did for > x86 dynamic stack realignment. The problem is understanding what the 'proper' unwind info is and figuring out what is wrong about it when it doesn't work. I used Bernd's comment about Rule #6 to handle the sp = sp AND reg issue, but I have a couple of more dwarf/cfi questions. One, can you explicitly make a copy of the stack pointer to another register and not make that register the new stack pointer? I want to save the old stack pointer before aligning it but when I do that I think that dwarfcfi.c automatically assumes that the new register is now the stack pointer and that is not what I want. I want the stack pointer to remain as the original register. My other question is about 'set_unexpected' and how that affects the generated unwind info. I noticed that a lot of my failing tests use 'set_unexpected' and I don't know what this function does or how it affects the generated code that would cause these tests in particular to fail. Steve Ellcey sellcey@imgtec.com