Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751299AbWEWH6X (ORCPT ); Tue, 23 May 2006 03:58:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751304AbWEWH6X (ORCPT ); Tue, 23 May 2006 03:58:23 -0400 Received: from embla.aitel.hist.no ([158.38.50.22]:64904 "HELO embla.aitel.hist.no") by vger.kernel.org with SMTP id S1751299AbWEWH6W (ORCPT ); Tue, 23 May 2006 03:58:22 -0400 Message-ID: <4472BFE4.8000605@aitel.hist.no> Date: Tue, 23 May 2006 09:55:16 +0200 From: Helge Hafting User-Agent: Debian Thunderbird 1.0.7 (X11/20051017) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "linux-os (Dick Johnson)" CC: Matheus Izvekov , Chris Wedgwood , Christoph Hellwig , LKML , Linus Torvalds , Andrew Morton , Dominik Brodowski Subject: Re: [RFC PATCH (take #2)] i386: kill CONFIG_REGPARM completely References: <20060520025353.GE9486@taniwha.stupidest.org> <20060520090614.GA9630@infradead.org> <20060520201357.GA32010@taniwha.stupidest.org> <20060520212049.GA11180@taniwha.stupidest.org> <305c16960605201500s6153e1doad87e4b85f15b53f@mail.gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 967 Lines: 23 linux-os (Dick Johnson) wrote: >On ix86 there are not enough registers to pass a significant parameter >list all in registers! Like when you are printk()ing a dotted-quad IP >address, etc. Registers ESI, EDI, and EBX are precious, that leaves >EAX, ECX, EDX and possibly EBP for only 4 parameters. You need 5 >for the dotted quad IP address. If the compiler were to use the >precious registers, the contents need to be saved on the stack. >That negates any advantage to passing parameters in registers. > > I had the impression that REGPARM in i386 only passed the first three arguments in registers, putting any further paramters on the stack? Ought to help for all those 3-argument or less functions. Helge Hafting - 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/