From owner-svn-src-head@FreeBSD.ORG Thu Jan 17 18:48:36 2013 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 98E2BFC5 for ; Thu, 17 Jan 2013 18:48:36 +0000 (UTC) (envelope-from lists@eitanadler.com) Received: from mail-la0-f44.google.com (mail-la0-f44.google.com [209.85.215.44]) by mx1.freebsd.org (Postfix) with ESMTP id 213B99F9 for ; Thu, 17 Jan 2013 18:48:35 +0000 (UTC) Received: by mail-la0-f44.google.com with SMTP id eb20so1908532lab.31 for ; Thu, 17 Jan 2013 10:48:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=eitanadler.com; s=0xdeadbeef; h=x-received:mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type :content-transfer-encoding; bh=VpGCW59xd/0P2ah/JSqk3amLtTCepHTrH5mWzk3zh10=; b=JEPU3YJDyhwgbrgyl5FlDKouI4C8Pe7bNgIZEsOnrNmzGQO0XN7ZcVmMr6nTX5lj5h WC6Ih8bo8bGmI7eXll8Z+P9OOKbf336bO29JEJBHnAp+f4DX4DvqDmaHF8idvrUJpie+ 9b2SB20pgPb3duseObrmdLx43IgH92GgOSzOY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type :content-transfer-encoding:x-gm-message-state; bh=VpGCW59xd/0P2ah/JSqk3amLtTCepHTrH5mWzk3zh10=; b=I5eCv5O2U8tfrvToEbuo4tW25U+euBZAwoBL/6q28JErQHT74DGhaJFE96LU3r+R1c 2HCo0J7pkWwIAP1w7+VolDnxisBCwO+cMtbmwB83FB12BeTKySZkSzLNzX8bLq4YVYDD y58zsdS0iLC6knrBnS7ldVyMHIDMtmv7sIt4pQDfAkpHBpZ+o+WfJ/vFmkQsaq+/PTeT ZwZ9BdEALrGShjrpnKcDZbX/Tq4JVqgFEEzsIukBbnrLcyRn+6pQuJ1WKWEQiOZBkEeM +p1sGghiD3ElPEuh7yPHBwfF3EtuNi0toxCF0BbCRsfElcXejn2vBlZIvK+AvD62+4dF ri+w== X-Received: by 10.112.82.136 with SMTP id i8mr2597703lby.74.1358448514848; Thu, 17 Jan 2013 10:48:34 -0800 (PST) MIME-Version: 1.0 Sender: lists@eitanadler.com Received: by 10.112.30.131 with HTTP; Thu, 17 Jan 2013 10:48:04 -0800 (PST) In-Reply-To: <201301171035.14799.jhb@freebsd.org> References: <201301160503.r0G53qie087155@svn.freebsd.org> <50F6ED68.50602@delphij.net> <201301171035.14799.jhb@freebsd.org> From: Eitan Adler Date: Thu, 17 Jan 2013 13:48:04 -0500 X-Google-Sender-Auth: bE8b3inw3pLkIKVvkMJSxBd5CW0 Message-ID: Subject: Re: svn commit: r245494 - head/bin/pwait To: John Baldwin Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Gm-Message-State: ALoCoQmG65JM6MculQ11ypJOWao9RFOZeAgr//yF5f5rvwDSs5re2UxAIRgUtEohGmDyMGPYMyVE Cc: "src-committers@freebsd.org" , Xin LI , Erik Cederstrand , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" , d@delphij.net X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Jan 2013 18:48:36 -0000 On 17 January 2013 10:35, John Baldwin wrote: > No, it is clearly a bug. It is a waste of time and adds obfuscation (and > runtime overhead) to go free a bunch of stuff just before a return() from > main(). It is by-design according to the clang folks. They have expressed in interest in offering a knob to change this behavior, but I do not know the status of it. That said, I believe Xin's recent commit fixed the issue of adding an additional free. IMHO the compiler should also be able to optimize this case of free out. FWIW I have a very strong feeling of D=C3=A9j=C3=A0 vu here: we have discus= sed this exact type of change before. --=20 Eitan Adler Source, Ports, Doc committer Bugmeister, Ports Security teams