From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 82048 invoked by alias); 2 Oct 2018 17:19:37 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 82033 invoked by uid 89); 2 Oct 2018 17:19:37 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy=333, risk X-HELO: simark.ca Received: from simark.ca (HELO simark.ca) (158.69.221.121) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 02 Oct 2018 17:19:35 +0000 Received: by simark.ca (Postfix, from userid 112) id 175361E9A1; Tue, 2 Oct 2018 13:19:34 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=simark.ca; s=mail; t=1538500774; bh=+4ynVdn1VqJXF+xqavFY3dWGep2QmiUKJCojmqeQl6U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ngENu89SqLzgSUjff19VhZ+AL0WcVi6NWGIqw4V5KNQhT7jS9MDaPGcjqu0+MqFXX 0J3VXYLOY0WmbmyMpR54l+3jmafYAjppuCAwFT8XHKtGoySnf8RNBZMwBQXfM2tqcw FlLW6IgW6op4IZkt87yW93IodiR+6LEyny545aXQ= Received: from simark.ca (localhost [127.0.0.1]) by simark.ca (Postfix) with ESMTP id 33DA11E197; Tue, 2 Oct 2018 13:19:31 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=simark.ca; s=mail; t=1538500771; bh=+4ynVdn1VqJXF+xqavFY3dWGep2QmiUKJCojmqeQl6U=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=s8EBbRILwvi0/TTPnZcu9H4Pe1a5pzKBIZsaYYtLN6XqWk8SK6jmWhBiY1zvQYIPA HS+utnz0FO3U0uILR8ppWhNldMNwKuPfTQGntbRQoshTNKiECeRZbjwgD7XOUP5Any OFdTz/B7lrUr+XgJRPswnr/hGjrGf4bUlk2ILJkQ= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 02 Oct 2018 17:19:00 -0000 From: Simon Marchi To: Trent Piepho Cc: gdb-patches@sourceware.org Subject: Re: [PATCH] Record ARM THUMB2 PLD/PLI cache instructions In-Reply-To: <1538431511.6709.18.camel@impinj.com> References: <20180928230437.4329-1-tpiepho@impinj.com> <1538431511.6709.18.camel@impinj.com> Message-ID: X-Sender: simark@simark.ca User-Agent: Roundcube Webmail/1.3.6 X-SW-Source: 2018-10/txt/msg00051.txt.bz2 On 2018-10-01 18:05, Trent Piepho wrote: >> In the manual, however, in table "Table A5-20 Load byte, memory >> hints", some encodings with >> Rt == 0b1111 decode to "UNPREDICTABLE". Should the record fail for >> those? I think currently >> with your patch we will accept them. I am thinking it would be good >> to fail, because since >> we can't know the side effects of such instruction, we risk showing >> some false information if >> we just assume nothing has changed. > > I'm not sure what document this is from, but in https://static.docs.arm > .com/ddi0406/c/DDI0406C_C_arm_architecture_reference_manual.pdf > > Table A6-20 is titled as above. > > Rather than this, I used the thumb2 supplement I found here: http://her > mes.wings.cs.wisc.edu/files/Thumb-2SupplementReferenceManual.pdf > > Section 3.3.3 had the most useful table and exhaustive list of possible > encodings for this type of thumb2 instruction. Not sure which section 3.3.3 you are referring to. But I must have been using an outdated version of the manual, in the version you linked there is indeed no unpredictable encodings. > I see now that not every possible addressing mode is supported for > PLD/PLI, and there are ways to encode a reserved addressing mode for > all instructions of this type. > > I've prepared a follow on patch that should provide an exhaustive check > for PLD and PLI instructions. It also enhances the check for other > instructions of this general format, but I've not verified that the > code is exhaustive there. It is at least better than it was. > >> If you are motivated, it would be nice to add a test for this >> instruction in arm_record_test, >> but I won't require it, since the current state is that this test >> isn't meant to test all >> possible instruction, and I don't want to impose that burden on you. > > I might that be THAT motivated, since I've never even used that test > feature. Err I'm not sure if you you meant that you are that motivated, or you are _not_ that motivated. In case you are, I'll be happy to provide any help you would need :). Simon