From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from stu.xidian.edu.cn (stumail.xidian.edu.cn [202.117.112.40]) by sourceware.org (Postfix) with SMTP id A7339386101C for ; Fri, 12 Feb 2021 14:57:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A7339386101C Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=stu.xidian.edu.cn Authentication-Results: sourceware.org; spf=none smtp.mailfrom=ryxi@stu.xidian.edu.cn Received: from [192.168.0.103] ([192.168.0.103] [120.208.101.154]) by stu.xidian.edu.cn (eYou MTA v8.1.0) with ESMTP id 2c0e1f257a7e69e05c5925007c8cf4a6 for ; Fri, 12 Feb 2021 23:01:57 +0800 X-Eyou-Smtpauth: ryxi@stu.xidian.edu.cn Message-ID: <24e20470145393c2c20ec469e94834c82d7ab08d.camel@stu.xidian.edu.cn> Subject: Re: [PATCH] MIPS: Fix PR target/98491 (ChangeLog) From: Xi Ruoyao Reply-To: Xi Ruoyao To: Jeff Law , Jakub Jelinek Cc: gcc-patches@gcc.gnu.org, Robert Suchanek , xry111@mengyan1223.wang Date: Fri, 12 Feb 2021 22:57:24 +0800 In-Reply-To: <316ada725a450fea738f4c5dc1d6abf554f0c323.camel@mengyan1223.wang> References: <4df733093ede4a3cc5dcb2688dcc9a2e5be4b721.camel@mengyan1223.wang> <184fa89ee34af9c3b13e99513a10aed1bd7c88af.camel@mengyan1223.wang> <20210104210018.GD725145@tucnak> <7825bdca-1a9a-90dc-671f-1dda98e1f5f4@redhat.com> <316ada725a450fea738f4c5dc1d6abf554f0c323.camel@mengyan1223.wang> Organization: Xidian University Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Eyou-Sender: X-Spam-Status: No, score=1.1 required=5.0 tests=BAYES_00, BODY_8BITS, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, KHOP_HELO_FCRDNS, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Level: * X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Feb 2021 14:57:39 -0000 Well, it just dislike my mail server :(. Switch to the mail server of my university. On 2021-02-12 22:54 +0800, Xi Ruoyao wrote: > Resend the mail.  I had to fill in a form to send mail to Robert. > > On 2021-02-12 22:17 +0800, Xi Ruoyao wrote: > > On 2021-01-11 01:01 +0800, Xi Ruoyao wrote: > > > Hi Jeff and Jakub, > > > > > > On 2021-01-04 14:19 -0700, Jeff Law wrote: > > > > On 1/4/21 2:00 PM, Jakub Jelinek wrote: > > > > > On Mon, Jan 04, 2021 at 01:51:59PM -0700, Jeff Law via Gcc-patches > > > > > wrote: > > > > > > > Sorry, I forgot to include the ChangeLog: > > > > > > > > > > > > > >     gcc/ChangeLog: > > > > > > >     > > > > > > >     2020-12-31  Xi Ruoyao > > > > > > >     > > > > > > >             PR target/98491 > > > > > > >             * config/mips/mips.c (mips_symbol_insns): Do not use > > > > > > >               MSA_SUPPORTED_MODE_P if mode is MAX_MACHINE_MODE. > > > > > > So I absolutely agree the current code is wrong as it does an out of > > > > > > bounds array access. > > > > > > > > > > > > > > > > > > Would it be better to instead to change MSA_SUPPORTED_MODE_P to > > > > > > evaluate > > > > > > to zero if MODE is MAX_MACHINE_MODE?  That would protect all the > > > > > > uses > > > > > > of > > > > > > MSA_SUPPORTED_MODE_P.    Something like this perhaps? > > > > > But MAX_MACHINE_MODE is the one past last valid mode, I'm not aware of > > > > > any target that would protect all macros that deal with modes that > > > > > way. > > > > > > > > > > So, perhaps best would be stop using the MAX_MACHINE_MODE as magic > > > > > value > > > > > for that function and instead use say VOIDmode that shouldn't normally > > > > > appear either? > > > > I think we have to allow VOIDmode because constants don't necessarily > > > > have modes.   And I certainly agree that using MAX_MACHINE_MODE like > > > > this is ugly and error prone (as we can see from the BZ). > > > > > > > > I also couldn't convince myself that the code and comments were actually > > > > consistent, particularly for MSA targets which the comment claims can > > > > never handle constants for ld/st (and thus should be returning 0 for > > > > MAX_MACHINE_MODE).  Though maybe mips_symbol_insns_1 ultimately handles > > > > that correctly. > > > > > > > > > > > > > > > > > > But I don't really see anything wrong on the mips_symbol_insns above > > > > > change either. > > > > Me neither.  I'm just questioning if bullet-proofing in the > > > > MSA_SUPPORTED_MODE_P would be a better option.  While I've worked in the > > > > MIPS port in the past, I don't really have any significannt experience > > > > with the MSA support. > > > > > > I can't understand the comment either.  To me it looks like it's possible > > > to > > > remove this "if (MSA_SUPPORTED_P (mode)) return 0;" > > > > > > CC Robert to get some help. > > > > Happy new lunar year folks. > > > > I found a newer email address of Robert.  Hope it is still being used. > > > > Could someone update MAINTAINERS file by the way? >