From owner-freebsd-current Tue Dec 11 15: 2:29 2001 Delivered-To: freebsd-current@freebsd.org Received: from mail12.speakeasy.net (mail12.speakeasy.net [216.254.0.212]) by hub.freebsd.org (Postfix) with ESMTP id 879B737B41B for ; Tue, 11 Dec 2001 15:02:23 -0800 (PST) Received: (qmail 17807 invoked from network); 11 Dec 2001 23:02:21 -0000 Received: from unknown (HELO laptop.baldwin.cx) ([64.81.54.73]) (envelope-sender ) by mail12.speakeasy.net (qmail-ldap-1.03) with SMTP for ; 11 Dec 2001 23:02:21 -0000 Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <20011206201803.Q14784-100000@gamplex.bde.org> Date: Tue, 11 Dec 2001 15:02:16 -0800 (PST) From: John Baldwin To: Bruce Evans Subject: Re: Patch Review: i386 asm cleanups in the kernel Cc: current@FreeBSD.org Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On 06-Dec-01 Bruce Evans wrote: > That gives a hint about where to look for the clobbering conventions. From > gcc/config/i386/i386.c: > > ! /* Set the cc_status for the results of an insn whose pattern is EXP. > ! On the 80386, we assume that only test and compare insns, as well > ! as SI, HI, & DI mode ADD, SUB, NEG, AND, IOR, XOR, BSF, ASHIFT, > ! ASHIFTRT, and LSHIFTRT instructions set the condition codes usefully. > ! Also, we assume that jumps, moves and sCOND don't affect the condition > ! codes. All else clobbers the condition codes, by assumption. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > ! > ! We assume that ALL integer add, minus, etc. instructions effect the > ! condition codes. This MUST be consistent with i386.md. > ! > ! We don't record any float test or compare - the redundant test & > ! compare check in final.c does not handle stack-like regs correctly. */ > ! > ! void > ! notice_update_cc (exp) > ! rtx exp; > > Application asms are apparently in the "All else" set. Ok, I've axed all the "cc" clobbers from the patch now. Any objections to it now? It's still at ~jhb/patches/i386_asm.patch. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message