From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 59048 invoked by alias); 18 Mar 2015 11:42:35 -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 59034 invoked by uid 89); 18 Mar 2015 11:42:34 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.1 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail-ob0-f175.google.com Received: from mail-ob0-f175.google.com (HELO mail-ob0-f175.google.com) (209.85.214.175) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Wed, 18 Mar 2015 11:42:33 +0000 Received: by obbgg8 with SMTP id gg8so29544238obb.1 for ; Wed, 18 Mar 2015 04:42:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=xozeS/K3PgvxeToNju98fOdWczTtyrA6/lJeT0f9c2s=; b=Bkz9YzARxHTNeHxvdBG4JpSmWEwOWa32MClIEY73hcV1ph6E0zusYudNz+ccofkTrh hK6qrEH0WWcvYGwkqXPjgGJu53dPKf9BOvPU1E6mwW+o7TDW/pMPhm0MXBZeKmoPheTi ax3wnpzwiSc2w0XifLGBE4GipcxJ0Gh5Xt6yWtrFOUt8DApmW0uxAd6+48XU4N310RP+ GbmrSSZkvZUbQUu3uSm/t76gpysENrxAFmMvPT+y5YsTKzyz9U7cK/1Rep5RwtuEmB6I GYjooAyRsmoZWG5w86S7GvS9ZY3vtQNzwe5eXWP7NMY1kuwPpSkw3hwbhKy8cIPTe6ry SfzQ== X-Gm-Message-State: ALoCoQnhIjwJSRN0FFfRTHCxKUdXqZvBLmxDfIeaB5EQGZDgI86G/PW+xDP4WN2WQ6NtitKfjNeX MIME-Version: 1.0 X-Received: by 10.182.28.39 with SMTP id y7mr55908180obg.11.1426678951985; Wed, 18 Mar 2015 04:42:31 -0700 (PDT) Received: by 10.202.221.214 with HTTP; Wed, 18 Mar 2015 04:42:31 -0700 (PDT) In-Reply-To: <55095252.3000306@arm.com> References: <55095252.3000306@arm.com> Date: Wed, 18 Mar 2015 11:42:00 -0000 Message-ID: Subject: Re: [PATCH, ARM, PR64208] LRA ICE Fix From: Yvan Roux To: Kyrill Tkachov 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: 2015-03/txt/msg00915.txt.bz2 HI Kyrill, On 18 March 2015 at 11:24, Kyrill Tkachov wrote: > Hi Yvan, > > > On 18/03/15 10:19, 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 ? >> >> 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. > > > As a general note, I think this patch should include the testcase from the > PR. > I can see that it's fairly self-contained. Yes, I wanted to find one that exhibits the issue on trunk as the PR testcase doesn't, but don't find one so far. If it's fine to include a testcase that don't fail without that patch on trunk, I can include it. Cheers, Yvan