From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 101388 invoked by alias); 16 Mar 2018 14:33:20 -0000 Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org Received: (qmail 101379 invoked by uid 89); 16 Mar 2018 14:33:19 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:265 X-HELO: mail-wm0-f51.google.com Received: from mail-wm0-f51.google.com (HELO mail-wm0-f51.google.com) (74.125.82.51) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 16 Mar 2018 14:33:18 +0000 Received: by mail-wm0-f51.google.com with SMTP id 139so3453135wmn.2 for ; Fri, 16 Mar 2018 07:33:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=wOBVdFrWff6lh0J+vPNmVVms35wPZdmfbrfNDk0tZ3k=; b=kRoI6pUSDbyStV/c/bkCl827Ex40wYl446jzL8+B4HDrlqQFHuojWmDIOrLuMWYMkD maZhtTOwypgdS8vgwKZ68Qesd/X3O5dbmLIuoKySgtXi83FvWAO4ewsUKu1DPQiSjfxz xHR21v/LPI5skSFsqx5n/7umQgcjc4nNphUuX06EuIaWzVz2rPPQ3J1HNCm4qVJuLJH1 DTSLHA+N7JCnmiBSOEYa61qvU3KmiN9ND3q7Ln94pCdRvShSdzBSyA1QfsYYiNBOvfUY XoiHKgFq4lzWNunDBBdmkE7VbopkWvZOxJFNqAFRnOmxxRnCAwnKqXmcOGWuj9f9oNJn dLJQ== X-Gm-Message-State: AElRT7Ep7pNT0PRIikUT9PTL4XWQsp2utouiml87CSH7ty2p+efkGTWy g3fAIBeXikvlr8h7MQZIMtGylks0j7FCxCye2oM= X-Google-Smtp-Source: AG47ELtzaaXCdIMpAPXorYHbZ1W2+pOaWcN5vQSW8m3xM3xTSd7tOW1bXgrA1/QmHWf9hfn7e+4eZRxa0gez9qP2kGo= X-Received: by 10.28.231.10 with SMTP id e10mr2078158wmh.125.1521210796265; Fri, 16 Mar 2018 07:33:16 -0700 (PDT) MIME-Version: 1.0 Received: by 10.223.172.71 with HTTP; Fri, 16 Mar 2018 07:32:35 -0700 (PDT) From: Manuel Lauss Date: Fri, 16 Mar 2018 14:33:00 -0000 Message-ID: Subject: How to debug LTO-related failures? To: gcc-help Content-Type: text/plain; charset="UTF-8" X-SW-Source: 2018-03/txt/msg00050.txt.bz2 Hello, Is there a guideline on how to best investigate LTO-related runtime failures? I've found that gcc-8 r258566 miscompiles ffmpeg-3.4.2 when built with lto, and I'd like to prepare a proper bug report. Thanks! Manuel Lauss