Return-Path: Delivered-To: apmail-httpd-dev-archive@www.apache.org Received: (qmail 68042 invoked from network); 26 Oct 2010 21:13:12 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 26 Oct 2010 21:13:12 -0000 Received: (qmail 53150 invoked by uid 500); 26 Oct 2010 21:13:11 -0000 Delivered-To: apmail-httpd-dev-archive@httpd.apache.org Received: (qmail 53059 invoked by uid 500); 26 Oct 2010 21:13:11 -0000 Mailing-List: contact dev-help@httpd.apache.org; run by ezmlm Precedence: bulk Reply-To: dev@httpd.apache.org list-help: list-unsubscribe: List-Post: List-Id: Delivered-To: mailing list dev@httpd.apache.org Received: (qmail 53042 invoked by uid 99); 26 Oct 2010 21:13:11 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 26 Oct 2010 21:13:11 +0000 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of minfrin@sharp.fm designates 72.32.122.20 as permitted sender) Received: from [72.32.122.20] (HELO chandler.sharp.fm) (72.32.122.20) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 26 Oct 2010 21:13:03 +0000 Received: from chandler.sharp.fm (localhost [127.0.0.1]) by chandler.sharp.fm (Postfix) with ESMTP id 16B8B48800B for ; Tue, 26 Oct 2010 16:12:43 -0500 (CDT) Received: from [10.0.0.251] (87-194-125-18.bethere.co.uk [87.194.125.18]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client did not present a certificate) (Authenticated sender: minfrin@sharp.fm) by chandler.sharp.fm (Postfix) with ESMTP id 3BBCA488009 for ; Tue, 26 Oct 2010 16:12:41 -0500 (CDT) Message-Id: From: Graham Leggett To: dev@httpd.apache.org In-Reply-To: <4CC73E19.8030302@rowe-clan.net> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v936) Subject: Re: svn commit: r1026668 - /httpd/httpd/trunk/modules/proxy/mod_proxy.h Date: Tue, 26 Oct 2010 23:12:38 +0200 References: <20101023193416.D431E238890A@eris.apache.org> <4CC33CC6.4070806@rowe-clan.net> <248F3A06-99A2-44F2-A3B3-259D1315E25E@sharp.fm> <5A682A3D-A9C7-4BFB-9139-E4BE140C6F23@sharp.fm> <4CC73E19.8030302@rowe-clan.net> X-Mailer: Apple Mail (2.936) X-Virus-Scanned: ClamAV using ClamSMTP On 26 Oct 2010, at 10:46 PM, William A. Rowe Jr. wrote: > It is not simply a bit mask. > > It's a bit mask, shift and shift extension, since this is an int > bitfield > and not unsigned. Two values, 0 and -1. Are you sure it's not just an AND followed by JNZ? We're only interested in whether the bit is set, we're not manipulating it to compare it to the int value "1" are we? > Great for fields that will be accessed once per request. > > Horrid performance for per-dir merging. > > Even to Jim's comment, an unsigned char would outperform a signed > char, > which has to be sign-extended into a full int. How does this affect a modern CPU cache, given that the enemy of a CPU cache is data size? Regards, Graham --