From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23645 invoked by alias); 24 Mar 2003 20:08:31 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 23582 invoked from network); 24 Mar 2003 20:08:30 -0000 Received: from unknown (HELO uniton.integrable-solutions.net) (62.212.99.186) by sources.redhat.com with SMTP; 24 Mar 2003 20:08:30 -0000 Received: from uniton.integrable-solutions.net (localhost [127.0.0.1]) by uniton.integrable-solutions.net (8.12.3/8.12.3/SuSE Linux 0.6) with ESMTP id h2OK4DH2010502; Mon, 24 Mar 2003 21:04:13 +0100 Received: (from gdr@localhost) by uniton.integrable-solutions.net (8.12.3/8.12.3/Submit) id h2OK4C69010501; Mon, 24 Mar 2003 21:04:12 +0100 X-Authentication-Warning: uniton.integrable-solutions.net: gdr set sender to gdr@integrable-solutions.net using -f To: Matt Austern Cc: Mark Mitchell , gcc@gcc.gnu.org, jason@redhat.com Subject: Re: C++: Why do we nreverse CLASSTYPE_TAGS References: From: Gabriel Dos Reis In-Reply-To: Organization: Integrable Solutions Date: Mon, 24 Mar 2003 20:48:00 -0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2003-03/txt/msg01482.txt.bz2 Matt Austern writes: | On Monday, March 24, 2003, at 11:21 AM, Mark Mitchell wrote: | | >> OK, I'll experiment with that approach. What threasold would you put | >> for "lots"? | > | > I dunno. Probably 10 or so, to start. With fewer than that, hashing | > can't possibly be a win. | | How expensive is the hash function? Unless it's pretty extreme, I'd | be surprised if you needed to get all the way to 10 to get a win. Actually, we have the hash function for free for the following reason: by caching the hash value, as suggested in a previous patch, we don't need to recompute it when we map a name to the associated type. That hash is already computed as a result of calling get_identifier(). -- Gaby