From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 20 Jan 2015 10:52:48 +0100 (CET) Received: from mailapp01.imgtec.com ([195.59.15.196]:18283 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011100AbbATJwqp3ghV (ORCPT ); Tue, 20 Jan 2015 10:52:46 +0100 Received: from KLMAIL01.kl.imgtec.org (unknown [192.168.5.35]) by Websense Email Security Gateway with ESMTPS id 56DB93D23D0A1; Tue, 20 Jan 2015 09:52:39 +0000 (GMT) Received: from LEMAIL01.le.imgtec.org (192.168.152.62) by KLMAIL01.kl.imgtec.org (192.168.5.35) with Microsoft SMTP Server (TLS) id 14.3.195.1; Tue, 20 Jan 2015 09:52:41 +0000 Received: from [192.168.154.96] (192.168.154.96) by LEMAIL01.le.imgtec.org (192.168.152.62) with Microsoft SMTP Server (TLS) id 14.3.210.2; Tue, 20 Jan 2015 09:52:40 +0000 Message-ID: <54BE2568.5080105@imgtec.com> Date: Tue, 20 Jan 2015 09:52:40 +0000 From: Markos Chandras User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: "Maciej W. Rozycki" CC: , Matthew Fortune Subject: Re: [PATCH RFC v2 12/70] MIPS: asm: asmmacro: Replace add instructions with "addui" References: <1421405389-15512-1-git-send-email-markos.chandras@imgtec.com> <1421405389-15512-13-git-send-email-markos.chandras@imgtec.com> <54BD3355.9010104@imgtec.com> In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.154.96] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 45359 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: Markos.Chandras@imgtec.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 01/19/2015 07:25 PM, Maciej W. Rozycki wrote: > On Mon, 19 Jan 2015, Maciej W. Rozycki wrote: > >>> sorry i might be missing something but why do you think this is an >>> important bug fix that should go into 3.19? the way i read the code it >>> seems that it can't go wrong at the moment. >> >> We shouldn't be using trapping instructions for address calculation. >> These macros have been wrong since the beginning, the MSA instructions >> they correspond to do not trigger an exception on an integer overflow in >> address calculation (none of the MIPS instruction does). > > And BTW, it is a bug in GAS too, that it does not accept ADDI for R6 -- > it should treat the instruction as a macro and expand it to an equivalent > LI + ADD sequence (using $at or `rd', if available, as a temporary to > store the immediate). Similarly to how microMIPS DADDI is handled for > example (where the hardware instruction has an unusually limited range of > the immediate argument, however GAS accepts any 16-bit). > > Maciej > CC'ing Matthew -- markos From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailapp01.imgtec.com ([195.59.15.196]:18283 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011100AbbATJwqp3ghV (ORCPT ); Tue, 20 Jan 2015 10:52:46 +0100 Message-ID: <54BE2568.5080105@imgtec.com> Date: Tue, 20 Jan 2015 09:52:40 +0000 From: Markos Chandras MIME-Version: 1.0 Subject: Re: [PATCH RFC v2 12/70] MIPS: asm: asmmacro: Replace add instructions with "addui" References: <1421405389-15512-1-git-send-email-markos.chandras@imgtec.com> <1421405389-15512-13-git-send-email-markos.chandras@imgtec.com> <54BD3355.9010104@imgtec.com> In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-Path: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: "Maciej W. Rozycki" Cc: linux-mips@linux-mips.org, Matthew Fortune Message-ID: <20150120095240.dczAa897mFmVqUVHlcyLXK2QZ5guSD9kVbgwlggoOIc@z> On 01/19/2015 07:25 PM, Maciej W. Rozycki wrote: > On Mon, 19 Jan 2015, Maciej W. Rozycki wrote: > >>> sorry i might be missing something but why do you think this is an >>> important bug fix that should go into 3.19? the way i read the code it >>> seems that it can't go wrong at the moment. >> >> We shouldn't be using trapping instructions for address calculation. >> These macros have been wrong since the beginning, the MSA instructions >> they correspond to do not trigger an exception on an integer overflow in >> address calculation (none of the MIPS instruction does). > > And BTW, it is a bug in GAS too, that it does not accept ADDI for R6 -- > it should treat the instruction as a macro and expand it to an equivalent > LI + ADD sequence (using $at or `rd', if available, as a temporary to > store the immediate). Similarly to how microMIPS DADDI is handled for > example (where the hardware instruction has an unusually limited range of > the immediate argument, however GAS accepts any 16-bit). > > Maciej > CC'ing Matthew -- markos