From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12734 invoked by alias); 9 Jul 2015 20:53:00 -0000 Mailing-List: contact jit-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Post: List-Help: List-Subscribe: Sender: jit-owner@gcc.gnu.org Received: (qmail 12718 invoked by uid 89); 9 Jul 2015 20:52:59 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Checked: by ClamAV 0.98.7 on sourceware.org X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 X-Spam-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on sourceware.org X-Spam-Level: X-HELO: mail-yk0-f181.google.com 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=snyqEod35oiwN2i1zesd8zP9y/2AGDqPWIAcolK/yxM=; b=k9gy3+lwsy4gjaVqnF28uDlh4p8dnTAbSGS0eoWNia4pnEVqBe8sr9+/3XtNuWH1XD JBJEL+ahXhGal6yM3UHNIN7HF8Kdfs0Vs1AItiewspz9gdaqNkUlBJTaab9a/bByVqiA WrSb2p2m+u0fcMIlYhwbKy0cZj+Rq2rkJ9gk9gUnYHENFB4AmIYJdBoiSmKbigiC4FaY uG213nx3khuwbXoiW/cW7IlNjCPcW9YBWe40lxwk8s9eP+bTOgSq7O7UjuK9Uhh8+6+Y 62rc6hZYrVSmVn8Hz3mPk/Ebncc+YXhoMWgTyXTS92EG8qcAfDpa/+CxOT9tV21qjrS6 RwNA== X-Gm-Message-State: ALoCoQnEOjVgx12l+iRRnQAPVnphsXOI1NDtqyarotJA4qXltYwkQ433OSyGJjPeaCkUOuwnpoTR MIME-Version: 1.0 X-Received: by 10.170.87.134 with SMTP id e128mr19332086yka.109.1436475177112; Thu, 09 Jul 2015 13:52:57 -0700 (PDT) In-Reply-To: <1436469764.24803.156.camel@surprise> References: <1436365266.24803.65.camel@surprise> <1436367926.24803.71.camel@surprise> <1436369443.24803.75.camel@surprise> <1436377619.24803.97.camel@surprise> <1436382217.24803.101.camel@surprise> <1436385256.24803.107.camel@surprise> <1436469764.24803.156.camel@surprise> Date: Thu, 01 Jan 2015 00:00:00 -0000 Message-ID: Subject: Re: Filed PR jit/66812 for the code generation issue From: Dibyendu Majumdar To: David Malcolm Cc: jit@gcc.gnu.org Content-Type: text/plain; charset=UTF-8 X-SW-Source: 2015-q3/txt/msg00057.txt.bz2 On 9 July 2015 at 20:22, David Malcolm wrote: >> but it does seem to have caused >> the optimization bug to go away - i.e. the tests now pass. I will run >> more tests tomorrow to see if this is true under all optimization >> settings. > > FWIW, I suspect that this is effectively just papering over the problem, > and that it will come back to bite us, just with a more complicated > reproducer :( > Yes agree. > Does something like: > > > function x(some_arg) > local IX > if ((some_arg or true) and false) then > IX = true > end; > return ((some_arg or true) and false) > end > assert(x() == false) > > > > exhibit the bug? (have never programmed Lua, so this probably even > isn't syntactically correct, but hopefully you get the idea, with > const-propagation of 10's value and typecode lots of code gets optimized > away, so using an arg of unknown type to thwart that and hopefully get > the bug to re-manifest itself). > Actually that is valid Lua. Since you aren't passing a value to x() then some_arg will be NIL. In Lua, NIL and false are false, everything else is true. The example above works okay as is, and also when I pass 10 to x(). As usual with certain bugs - only a specific set of circumstances trigger it. > > (Note that I've managed to isolate a minimal reproducer for the problem, > as noted in another mail this thread) > Yes that is very good news. Hope you will soon discover the root cause. Thanks and Regards Dibyendu