From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 97122 invoked by alias); 6 May 2015 09:50:12 -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 97112 invoked by uid 89); 6 May 2015 09:50:11 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-qc0-f180.google.com Received: from mail-qc0-f180.google.com (HELO mail-qc0-f180.google.com) (209.85.216.180) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Wed, 06 May 2015 09:50:09 +0000 Received: by qctx5 with SMTP id x5so1762271qct.0 for ; Wed, 06 May 2015 02:50:07 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.55.16.140 with SMTP id 12mr63781221qkq.39.1430905807206; Wed, 06 May 2015 02:50:07 -0700 (PDT) Received: by 10.140.23.7 with HTTP; Wed, 6 May 2015 02:50:07 -0700 (PDT) Reply-To: ramrad01@arm.com In-Reply-To: References: Date: Wed, 06 May 2015 09:50:00 -0000 Message-ID: Subject: Re: [PATCH, ARM, PR64208] LRA ICE Fix From: Ramana Radhakrishnan To: Yvan Roux Cc: "gcc-patches@gcc.gnu.org" , Ramana Radhakrishnan , Richard Earnshaw , Vladimir Makarov Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2015-05/txt/msg00414.txt.bz2 On Thu, Apr 30, 2015 at 6:49 PM, Yvan Roux wrote: > Hi, > > On 23 March 2015 at 18:47, Yvan Roux wrote: >> Hi, >> >> On 23 March 2015 at 17:08, Ramana Radhakrishnan >> wrote: >>> On Wed, Mar 18, 2015 at 10:19 AM, Yvan Roux wrote: >>>> Hi, >>>> >>>> This is a fix for PR64208 where LRA loops when dealing with >>>> iwmmxt_arm_movdi insn. As explain in the PR, the issue was introduced >>>> on trunk and 4.9 branch by fix of PR rtl-optimization/60969 and then >>>> workaround by r211798 (-fuse-caller-save enable for ARM). >>>> >>>> The changes in IRA cost made by PR60969, changed the register class of >>>> this insn output from GENERAL_REGS to IWMMXT_REGS, and the >>>> redundancies in the insn pattern alternatives description force LRA to >>>> reload the pseudo, which generates the same iwmmxt_arm_movdi insn, >>>> which can't be resolved, and so on ... >>>> >>>> Removing the redundancies fixes the issue, as LRA find that >>>> alternative 8 (Uy => y) matches. >>>> >>>> This issue is present in 4.9 branch, but latent on trunk (the >>>> clobbering of IP and CC information added during -fuse-caller-save >>>> patch changed the register allocation). >>>> >>>> Cross compiled and regression tested on ARM targets (but not on an >>>> IWMMXT one), is it ok for trunk and 4.9 branch ? >>> >>> >>> This looks sane. It doesn't look reasonable for alternatives to be >>> duplicating each other. >>> >>> Given I have neither the time nor the hardware to test this patch on, >>> I'd rather someone with an interest in iwMMX possibly folks from >>> Marvell can pick up testing for this patch. >> >> Ok, Thanks Ramana, I'll wait for somebody able to test it. Notice, >> that without this patch on the 4.9 branch, building a cross compiler >> which default to iWMMXT architectures ICE on that during LRA while >> building of libgcc. > > I got an access to a cubox with an armada 510 and finally managed to > validate this patch (~ 1week for bootstrap + make check !). So, > bootstrap is ok and no regession. is it Ok for trunk and branches > (the issue was observed on 4.9) ? Notice that I've only tested it for > trunk and I don't plan to validate it on the branches ! ;) OK for trunk - Thanks for taking the extra effort to get an armada board to validate this on. it's ok for the branches only if you validate it on the branches. If someone is interested in the bug fix they can always pick it up Ramana > > Thanks > Yvan > > >> Cheers, >> Yvan >> >>> regards >>> Ramana >>> >>>> >>>> Rq: I think that adding IP and CC clobbers to >>>> CALL_INSN_FUNCTION_USAGE, as specified by AAPCS, in 4.9 branch is >>>> something we need too, I've a patch for that if you agree on that. >>>> >>>> Thanks, >>>> Yvan >>>> >>>> 2105-03-17 Yvan Roux >>>> >>>> PR target/64208 >>>> * config/arm/iwmmxt.md ("*iwmmxt_arm_movdi"): Cleanup redundant >>>> alternatives.