Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755648Ab2EWQnb (ORCPT ); Wed, 23 May 2012 12:43:31 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:46316 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752451Ab2EWQn2 convert rfc822-to-8bit (ORCPT ); Wed, 23 May 2012 12:43:28 -0400 MIME-Version: 1.0 In-Reply-To: <4FBD10D5.6080602@zytor.com> References: <1337684026-19740-1-git-send-email-bp@amd64.org> <1337789429.9783.16.camel@laptop> <4FBD0C47.70600@zytor.com> <20120523161932.GN14757@aftab.osrc.amd.com> <1337790571.9783.28.camel@laptop> <4FBD10D5.6080602@zytor.com> From: Linus Torvalds Date: Wed, 23 May 2012 09:43:07 -0700 X-Google-Sender-Auth: W14zdYr6_Qw-ULVGYmBexHtHRec Message-ID: Subject: Re: [tip:x86/mce] x86/bitops: Move BIT_64() for a wider use To: "H. Peter Anvin" Cc: Peter Zijlstra , Borislav Petkov , mingo@kernel.org, linux-kernel@vger.kernel.org, frank.arnold@amd.com, akpm@linux-foundation.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 979 Lines: 26 On Wed, May 23, 2012 at 9:31 AM, H. Peter Anvin wrote: >>> >>> And it should return UL for shift values < 32 and ULL otherwise. >> > > Why do you want that behavior? ?That seems bizarre... We *have* to have that behavior. A 64-bit value on a 32-bit architecture has fundamentally different semantics than a 32-bit one. It expands arithmetic, but it has other semantic differences too. Think "printf()" etc. We don't want to force people to do 64-bit arithmetic on x86-32 when they are working with BIT(0), for chrissake! So if people make BIT(0) be a 64-bit value on a 32-bit architecture, I'm going to run around naked with a chainsaw, and call people morons. That's just not acceptable. Linus -- 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/