From ... Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!newsfeeds.belnet.be!news.belnet.be!deine.net!hamster.europeonline.net!newsfeed.europeonline.net!nslave.kpnqwest.net!nloc.kpnqwest.net!nmaster.kpnqwest.net!nreader2.kpnqwest.net.POSTED!not-for-mail Newsgroups: comp.lang.lisp Subject: Re: data hygiene [Re: Why is Scheme not a Lisp?] References: <87u1rkl068.fsf@charter.net> <87wuwg1b05.fsf@photino.sid.rice.edu> <87ofhrc3ed.fsf@charter.net> <874rjj1ve1.fsf@photino.sid.rice.edu> <87it7yz2sf.fsf@photino.sid.rice.edu> <87d6y5heq2.fsf@becket.becket.net> <87elilwsnx.fsf@photino.sid.rice.edu> <87u1rfn07o.fsf@becket.becket.net> <87k7sbtzp5.fsf@photino.sid.rice.edu> <871yej1v0h.fsf@becket.becket.net> <87y9grsf <3225566321428508@naggum.net> <3C97C8EA.38FFD47A@motorola.com> Mail-Copies-To: never From: Erik Naggum Message-ID: <3225571208798099@naggum.net> Organization: Naggum Software, Oslo, Norway Lines: 29 User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 19 Mar 2002 23:59:56 GMT X-Complaints-To: newsmaster@KPNQwest.no X-Trace: nreader2.kpnqwest.net 1016582396 193.71.199.50 (Wed, 20 Mar 2002 00:59:56 MET) NNTP-Posting-Date: Wed, 20 Mar 2002 00:59:56 MET Xref: archiver1.google.com comp.lang.lisp:29641 * Paul Dietz | *If* the running time of your algorithm is dominated by memory latency | rather than memory bandwidth the alist search could be up to twice as | fast, since its loads are more parallelizable. Are you kidding or something? | The longest sequence of dependent loads in the alist search has length | N+1, vs. 2N-1 for the plist. This is assuming you have a machine that | can have multiple loads 'in the air' at once. How the hell is caar+cdr any different from car+cddr? How do you normally set up alists and plists? Even after a copy-tree (or GC) that copies cons celle so they are allocated in the order they are visited, the distances are _exactly_ the same. Just work it out. | Put another way: you can arrange the loads in the alist search so that | there's a longer distance between the load and when the data is actually | used, which might reduce pipeline stalls. Please show me how this is done. I think you are aggressively clueless by now, but I am always open to refinement and even contradiction if you just do something smarter. /// -- In a fight against something, the fight has value, victory has none. In a fight for something, the fight is a loss, victory merely relief.