From owner-cvs-all Tue Apr 2 21:25:11 2002 Delivered-To: cvs-all@freebsd.org Received: from a96180.upc-a.chello.nl (a96180.upc-a.chello.nl [62.163.96.180]) by hub.freebsd.org (Postfix) with ESMTP id F285A37B419; Tue, 2 Apr 2002 21:25:06 -0800 (PST) Received: by a96180.upc-a.chello.nl (Postfix, from userid 1001) id 2DA8E2170; Wed, 3 Apr 2002 07:25:05 +0200 (CEST) Date: Wed, 3 Apr 2002 07:25:04 +0200 From: Jeroen Ruigrok/asmodai To: Kenneth Culver Cc: Dag-Erling Smorgrav , Matthew Dillon , Mike Barcroft , "M. Warner Losh" , jake@locore.ca, cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/i386/i386 critical.c src/sys/i386/include cpufunc.h critical.h src/sys/i386/isa apic_vector.s icu_vector.s src/sys/kern kern_fork.c kern_proc.c kern_switch.c src/sys/alpha/alph Message-ID: <20020403052504.GJ78613@daemon.ninth-circle.org> References: <20020402163939.M47850-100000@alpha.yumyumyum.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020402163939.M47850-100000@alpha.yumyumyum.org> User-Agent: Mutt/1.3.28i Organisation: Ninth Circle Enterprises Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG -On [20020402 23:45], Kenneth Culver (culverk@alpha.yumyumyum.org) wrote: >> Using spaces instead of tabs, especially in headers, has a noticeable >> (negative) impact on compilation speed. We could speed buildworld up >> significantly by stripping comments and superfluous whitespace from the >> headers we install in /usr/obj. > >This I didn't know, but it makes sense. It does, since the first production rule in any grammar of a language is often to match whitespace. [Since it occurs most often, placing it at the top makes a lot of sense.] The parser has to iterate 8 times instead of 1 time for a single tab character. How much gain you really get I don't know, that would need to be timed. You can always look at: http://ccache.samba.org/ to improve compilation speed. -- Jeroen Ruigrok van der Werven / asmodai / Kita no Mono asmodai@[wxs.nl|xmach.org], finger asmodai@ninth-circle.org http://www.softweyr.com/asmodai/ | http://www.[tendra|xmach].org/ Cling, cling to your mind, my Words... To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message