From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Tue, 19 Oct 2004 15:02:16 +0100 (BST) Received: from [IPv6:::ffff:145.253.187.134] ([IPv6:::ffff:145.253.187.134]:30149 "EHLO mail01.baslerweb.com") by linux-mips.org with ESMTP id ; Tue, 19 Oct 2004 15:02:04 +0100 Received: from mail01.baslerweb.com (localhost.localdomain [127.0.0.1]) by localhost.domain.tld (Basler) with ESMTP id 1D4C5134048; Tue, 19 Oct 2004 16:01:17 +0200 (CEST) Received: from comm1.baslerweb.com (unknown [172.16.13.2]) by mail01.baslerweb.com (Basler) with ESMTP id 1A236134044; Tue, 19 Oct 2004 16:01:17 +0200 (CEST) Received: from vclinux-1.basler.corp (localhost [172.16.13.253]) by comm1.baslerweb.com with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2657.72) id 4YRPLWP2; Tue, 19 Oct 2004 16:01:50 +0200 From: Thomas Koeller Organization: Basler AG To: "Linux/MIPS Development" Subject: jump instruction in delay slot Date: Tue, 19 Oct 2004 16:05:47 +0200 User-Agent: KMail/1.6.2 Cc: Manish Lachwani MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <200410191605.47543.thomas.koeller@baslerweb.com> Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 6099 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: thomas.koeller@baslerweb.com Precedence: bulk X-list: linux-mips Hi, the following code snippet is from arch/mips/pmc-sierra/yosemite/irq-handler.S: ll_duart_irq: li a0, 4 move a1, sp jal do_IRQ j ret_from_irq I wonder if this is correct. AFAIK, a jump instruction must not occupy the delay slot of another branch or jump instruction. Since the 'jal' returns to the first instruction after the delay slot, I would expect the effect of the 'j' instruction to be cancelled. Or is this some kind of trick I do not understand? tk -- -------------------------------------------------- Thomas Koeller, Software Development Basler Vision Technologies thomas dot koeller at baslerweb dot com http://www.baslerweb.com ==============================