From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14149 invoked by alias); 25 Apr 2002 22:13:28 -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 14134 invoked from network); 25 Apr 2002 22:13:27 -0000 Received: from unknown (HELO potter.sfbay.redhat.com) (205.180.83.107) by sources.redhat.com with SMTP; 25 Apr 2002 22:13:27 -0000 Received: from dot.sfbay.redhat.com (dot.sfbay.redhat.com [172.16.24.7]) by potter.sfbay.redhat.com (8.11.6/8.11.6) with ESMTP id g3PMCov01002; Thu, 25 Apr 2002 15:12:50 -0700 Received: (from rth@localhost) by dot.sfbay.redhat.com (8.11.6/8.11.6) id g3PMDRx02534; Thu, 25 Apr 2002 15:13:27 -0700 X-Authentication-Warning: dot.sfbay.redhat.com: rth set sender to rth@redhat.com using -f Date: Thu, 25 Apr 2002 15:15:00 -0000 From: Richard Henderson To: Wei Qin Cc: nathan@cs.bris.ac.uk, kelley.r.cook@gm.com, Preeti Aira , gcc , gcc-help Subject: Re: Number of 1's in 64 bit number...[don't read if not interested in algos/math...] Message-ID: <20020425151327.A2527@redhat.com> Mail-Followup-To: Richard Henderson , Wei Qin , nathan@cs.bris.ac.uk, kelley.r.cook@gm.com, Preeti Aira , gcc , gcc-help References: <3CC83D87.506F1499@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from wqin@EE.Princeton.EDU on Thu, Apr 25, 2002 at 03:12:07PM -0400 X-SW-Source: 2002-04/txt/msg01352.txt.bz2 On Thu, Apr 25, 2002 at 03:12:07PM -0400, Wei Qin wrote: > On a x86 linux platform, it takes 80% more time than the table lookup one. On hot cache, maybe. On cold cache the arithmetic will definitely be faster. r~