From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH] [PKT_SCHED] CLS_U32: Use ffs() instead of C code on hash mask to get first set bit. Date: Thu, 08 Nov 2007 08:45:31 -0500 Message-ID: <1194529531.5743.9.camel@localhost> References: 20071107.012220.17723288.davem@davemloft.net <1194520067-20868-1-git-send-email-radu.rendec@ines.ro> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, jarkao2@o2.pl, davem@davemloft.net To: Radu Rendec Return-path: Received: from wa-out-1112.google.com ([209.85.146.178]:30865 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756693AbXKHNpq (ORCPT ); Thu, 8 Nov 2007 08:45:46 -0500 Received: by wa-out-1112.google.com with SMTP id v27so203926wah for ; Thu, 08 Nov 2007 05:45:45 -0800 (PST) In-Reply-To: <1194520067-20868-1-git-send-email-radu.rendec@ines.ro> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Thu, 2007-08-11 at 13:07 +0200, Radu Rendec wrote: > Computing the rank of the first set bit in the hash mask (for using later > in u32_hash_fold()) was done with plain C code. Using ffs() instead makes > the code more readable and improves performance (since ffs() is better > optimized in assembler). > > Using the conditional operator on hash mask before applying ntohl() also > saves one ntohl() call if mask is 0. > > Signed-off-by: Radu Rendec Acked-by: Jamal Hadi Salim cheers, jamal