Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 5 Apr 2001 08:03:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 5 Apr 2001 08:03:24 -0400 Received: from mail.zmailer.org ([194.252.70.162]:31748 "EHLO zmailer.org") by vger.kernel.org with ESMTP id ; Thu, 5 Apr 2001 08:03:08 -0400 Date: Thu, 5 Apr 2001 15:02:19 +0300 From: Matti Aarnio To: Bart Trojanowski Cc: Manoj Sontakke , LKML Subject: Re: which gcc version? Message-ID: <20010405150219.B873@mea-ext.zmailer.org> In-Reply-To:

Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: ; from bart@jukie.net on Thu, Apr 05, 2001 at 07:37:03AM -0400 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 05, 2001 at 07:37:03AM -0400, Bart Trojanowski wrote: > On Thu, 5 Apr 2001, Manoj Sontakke wrote: > gcc requires a function call to do a mul/div on a long long. There is no > easy way to do a 64bit op of this type on a 32 bit CPU... Actually there is -- presuming your CPU has lots of registers, which i386 does not have... This rule -- "no -lgcc in kernel code" -- is to trap code which in fast-paths would call those slow routines. Fastpaths should either not grok such values, or at most use shifts. To think of it, there really should be explicitely callable versions of these with LinuxKernel names for them, not gcc builtins.? That way people would *know* they are doing something, which is potentially very slow. (And the API would not change from underneath them.) > Cheers, > Bart. > -- > WebSig: http://www.jukie.net/~bart/sig/ /Matti Aarnio - 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/