From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261582AbUBURNJ (ORCPT ); Sat, 21 Feb 2004 12:13:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261584AbUBURNJ (ORCPT ); Sat, 21 Feb 2004 12:13:09 -0500 Received: from fw.osdl.org ([65.172.181.6]:19153 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S261582AbUBURND (ORCPT ); Sat, 21 Feb 2004 12:13:03 -0500 Date: Sat, 21 Feb 2004 09:18:14 -0800 (PST) From: Linus Torvalds To: Pavel Machek cc: Stephen Hemminger , ak@suse.de, linux-kernel@vger.kernel.org Subject: Re: kernel/microcode.c error from new 64bit code In-Reply-To: <20040221141608.GB310@elf.ucw.cz> Message-ID: References: <20040218145218.6bae77b5@dell_ss3.pdx.osdl.net> <20040221141608.GB310@elf.ucw.cz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 21 Feb 2004, Pavel Machek wrote: > > > + wrmsr(MSR_IA32_UCODE_WRITE, > > + (unsigned long) uci->mc->bits, > > + (unsigned long) uci->mc->bits >> 16 >> 16); > ~~~~~~~~~~~~ > > I see what you are doing, but this is evil. At least comment /* ">> 32" > is undefined on i386 */ ? Sorry, but you're wrong. ">> 32" is underfined PERIOD! It has nothing to do with x86, it's a C standards issue. It's undefined on any 32-bit architecture. (shifting by the wordsize or bigger is simply not a defined C operation). The above is not evil. The above is the standard way of doing this in C if you know the word-size is 32-bits or bigger. Linus