Newsgroups: php.internals Path: news.php.net Xref: news.php.net php.internals:74409 Return-Path: Mailing-List: contact internals-help@lists.php.net; run by ezmlm Delivered-To: mailing list internals@lists.php.net Received: (qmail 85943 invoked from network); 21 May 2014 12:34:44 -0000 Received: from unknown (HELO lists.php.net) (127.0.0.1) by localhost with SMTP; 21 May 2014 12:34:44 -0000 Authentication-Results: pb1.pair.com smtp.mail=lester@lsces.co.uk; spf=permerror; sender-id=unknown Authentication-Results: pb1.pair.com header.from=lester@lsces.co.uk; sender-id=unknown Received-SPF: error (pb1.pair.com: domain lsces.co.uk from 217.147.176.210 cause and error) X-PHP-List-Original-Sender: lester@lsces.co.uk X-Host-Fingerprint: 217.147.176.210 mail4-3.serversure.net Linux 2.6 Received: from [217.147.176.210] ([217.147.176.210:55150] helo=mail4.serversure.net) by pb1.pair.com (ecelerity 2.1.1.9-wez r(12769M)) with ESMTP id 03/68-24198-26D9C735 for ; Wed, 21 May 2014 08:34:43 -0400 Received: (qmail 5434 invoked by uid 89); 21 May 2014 12:34:39 -0000 Received: by simscan 1.3.1 ppid: 5426, pid: 5430, t: 0.3049s scanners: attach: 1.3.1 clamav: 0.96/m:52 Received: from unknown (HELO linux-dev4.lsces.org.uk) (lester@rainbowdigitalmedia.org.uk@81.138.11.136) by mail4.serversure.net with ESMTPA; 21 May 2014 12:34:39 -0000 Message-ID: <537C9E3A.6010507@lsces.co.uk> Date: Wed, 21 May 2014 13:38:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: internals@lists.php.net References: <537BC669.2030704@sugarcrm.com> <20140520230249.E326826082D@dd15934.kasserver.com> <266288285382887601@unknownmsgid> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [PHP-DEV] Re: 64bit and phpng, votes and plans From: lester@lsces.co.uk (Lester Caine) On 21/05/14 08:41, Arvids Godjuks wrote: > And compare it. Because there is no hard > facts about the performance of 64 bit vs 32 bit type usage - just > speculation about CPU cache misses and so on. And I learned over the years > that people, designing those CPU's, are sneaky and sometimes results defy > the logic. And there are hints that actually full 64 bit types may be > faster than 32 bit usage for memory optimization. Having been looking at the hardware side of things again, even older 32bit processors support the MMX/SSX registers and instructions which provide 64bit maths on these processors and the latest AVX extensions already provide 256bit maths on more modern processors since 2011. These registers also provide parallel processing of smaller data sizes being part of the SIMD facility, Compatibility across processors is a problem, but even the higher spec VIA processors support it ... along with support for hardware SHA hashing. If performance is critical, then targeting a specific hardware configuration may help, but there may also be opportunities for selective improvements targeting the available hardware. -- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk Rainbow Digital Media - http://rainbowdigitalmedia.co.uk