Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753408Ab3JaMDf (ORCPT ); Thu, 31 Oct 2013 08:03:35 -0400 Received: from mail-ea0-f171.google.com ([209.85.215.171]:51081 "EHLO mail-ea0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751772Ab3JaMDe (ORCPT ); Thu, 31 Oct 2013 08:03:34 -0400 Message-ID: <52724712.6020809@linux.com> Date: Thu, 31 Oct 2013 13:03:30 +0100 From: Levente Kurusa Reply-To: levex@linux.com User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Richard Weinberger , =?UTF-8?B?6Z+p56OK?= CC: Linux Kernel Mailing List Subject: Re: A simple question of a linux kernel beginner References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 996 Lines: 25 2013-10-31 12:57 keltezéssel, Richard Weinberger írta: > On Thu, Oct 31, 2013 at 12:31 PM, 韩磊 wrote: >> May I can use the ''double" as a basic variables? >> >> When I define the "double" as a function return type in linux kernel,the error >> is "error: SSE register return with SSE disabled". >> >> How to fix it?? > > Don't do it. :) > In kernel land we don't want FPU stuff because it slows the mode switch down. > If you *really* need to use the FPU look how the raid6 or crypto code does. Not only it slows down the switches, but if there is no FPU, then it would need the so-called floating-point-library. Which would slow down the code, but the kernel needs to be as fast as it can. -- Regards, Levente Kurusa -- 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/