From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756646AbbCEPWZ (ORCPT ); Thu, 5 Mar 2015 10:22:25 -0500 Received: from mail-lb0-f175.google.com ([209.85.217.175]:42157 "EHLO mail-lb0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752360AbbCEPWY (ORCPT ); Thu, 5 Mar 2015 10:22:24 -0500 From: Rasmus Villemoes To: linux-kernel@vger.kernel.org Cc: "Peter Zijlstra \(Intel\)" , Tejun Heo , Andrew Morton Subject: Re: [RFC] lib/vsprintf.c: Even faster decimal conversion Organization: D03 References: <1424476281-26873-1-git-send-email-linux@rasmusvillemoes.dk> X-Hashcash: 1:20:150305:akpm@linux-foundation.org::3eYZGQTlY+CkxyhE:0000000000000000000000000000000000001DG7 X-Hashcash: 1:20:150305:tj@kernel.org::4Ik3QGGxhGeJhOri:00001Hax X-Hashcash: 1:20:150305:linux-kernel@vger.kernel.org::4gB+iPKiBtZDJ3iD:0000000000000000000000000000000002qXI X-Hashcash: 1:20:150305:peterz@infradead.org::AP4AUkKsD2rj7c/Q:000000000000000000000000000000000000000004uy4 Date: Thu, 05 Mar 2015 16:22:21 +0100 In-Reply-To: <1424476281-26873-1-git-send-email-linux@rasmusvillemoes.dk> (Rasmus Villemoes's message of "Sat, 21 Feb 2015 00:51:20 +0100") Message-ID: <87r3t3eafm.fsf@rasmusvillemoes.dk> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 21 2015, Rasmus Villemoes wrote: > [...] decimal conversion [...] it does indeed seem like there is > something to be gained, especially on 64 bits. > > $ ./test64 > Distribution Function Cycles/conv Conv/1 sec > uniform([10, 2^64-1]) linux_put_dec 127.72 23047567 > uniform([10, 2^64-1]) rv_put_dec 60.73 45932786 > +/- -52.45% +99.30% [...] > 3 + neg_binom(0.50) linux_put_dec 16.85 159560933 > 3 + neg_binom(0.50) rv_put_dec 12.59 204607570 > +/- -25.31% +28.23% I'm assuming the underwhelming response means NAK. Rasmus