Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758301Ab2HJVIa (ORCPT ); Fri, 10 Aug 2012 17:08:30 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:45432 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752853Ab2HJVI1 (ORCPT ); Fri, 10 Aug 2012 17:08:27 -0400 Date: Fri, 10 Aug 2012 14:08:24 -0700 (PDT) Message-Id: <20120810.140824.1942743961348792495.davem@davemloft.net> To: jengelh@inai.de Cc: dhowells@redhat.com, arnd@arndb.de, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dmitry.kasatkin@intel.com Subject: Re: [PATCH] MPILIB: Provide count_leading/trailing_zeros() based on arch functions From: David Miller In-Reply-To: References: <5723.1342794099@warthog.procyon.org.uk> <20120720.174641.159144353919647856.davem@davemloft.net> X-Mailer: Mew version 6.5 on Emacs 24.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1097 Lines: 27 From: Jan Engelhardt Date: Fri, 10 Aug 2012 14:51:49 +0200 (CEST) > > On Saturday 2012-07-21 02:46, David Miller wrote: >>> Arnd Bergmann wrote: >>> >>>> I don't generally like to put stuff into asm-generic when it's unlikely >>>> to be overridden by architectures. It would really belong into >>>> include/linux, but then again we have all the other bitops in asm-generic >>>> as well, so whatever... >>> >>> Some arches (such as Sparc, I think) have count-leading-zero instructions. >> >>Yes, newer sparc64 chips have leading-zero-detect, and I was pretty >>sure that powerpc had something similar. It's called count-leading- >>zeros or something like that. > > And gcc has a __builtin_clz. Which I can't use. I have to patch the code at run time based upon whether the cpu has the 'lzd' instruction or not. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/