From owner-freebsd-hackers@FreeBSD.ORG Thu Jun 18 13:52:44 2015 Return-Path: Delivered-To: freebsd-hackers@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 762CBF42 for ; Thu, 18 Jun 2015 13:52:44 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id A905261F for ; Thu, 18 Jun 2015 13:52:43 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id QAA16810; Thu, 18 Jun 2015 16:52:41 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1Z5aFF-000DQz-6r; Thu, 18 Jun 2015 16:52:41 +0300 Message-ID: <5582CCF1.8010505@FreeBSD.org> Date: Thu, 18 Jun 2015 16:51:45 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Konstantin Belousov CC: "freebsd-hackers@freebsd.org" Subject: Re: allow ffs & co. a binary search References: <20150607081315.7c0f09fb@B85M-HD3-0.alogt.com> <5573EA5E.40806@selasky.org> <20150607195245.62dc191f@B85M-HD3-0.alogt.com> <20150607135453.GH2499@kib.kiev.ua> <558175FA.4040106@FreeBSD.org> <20150617165331.GA2080@kib.kiev.ua> In-Reply-To: <20150617165331.GA2080@kib.kiev.ua> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Jun 2015 13:52:44 -0000 On 17/06/2015 19:53, Konstantin Belousov wrote: > AFAIR it was about 'sufficiently smart compiler' and the fact that the > functions are not on the hottest paths. It seems that sufficiently smart compilers still do not exist :-) At least as far as compilers that are used for compiling FreeBSD are considered. [Offtopic] my impression is that lately smartness of compilers is mostly being improved by various tricks and shortcuts (undefined behavior, etc), rather than by recognizing patterns in the C code that could be turned into more efficient machine code. -- Andriy Gapon