From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 16 Apr 2007 15:01:44 +0100 (BST) Received: from localhost.localdomain ([127.0.0.1]:43746 "EHLO dl5rb.ham-radio-op.net") by ftp.linux-mips.org with ESMTP id S20023278AbXDPOBm (ORCPT ); Mon, 16 Apr 2007 15:01:42 +0100 Received: from denk.linux-mips.net (denk.linux-mips.net [127.0.0.1]) by dl5rb.ham-radio-op.net (8.13.8/8.13.8) with ESMTP id l3GE1ejI031069; Mon, 16 Apr 2007 15:01:40 +0100 Received: (from ralf@localhost) by denk.linux-mips.net (8.13.8/8.13.8/Submit) id l3GE1ck4031068; Mon, 16 Apr 2007 15:01:38 +0100 Date: Mon, 16 Apr 2007 15:01:38 +0100 From: Ralf Baechle To: Thiemo Seufer Cc: Zhang Fuxin , tiansm@lemote.com, linux-mips@linux-mips.org Subject: Re: [PATCH 2/16] arch related Makefile update for lemote fulong mini-PC Message-ID: <20070416140137.GB28217@linux-mips.org> References: <11766507651736-git-send-email-tiansm@lemote.com> <11766507661317-git-send-email-tiansm@lemote.com> <11766507661726-git-send-email-tiansm@lemote.com> <20070415222847.GA1402@networkno.de> <4623387F.3070905@lemote.com> <20070416124422.GB1402@networkno.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070416124422.GB1402@networkno.de> User-Agent: Mutt/1.4.2.2i 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: 14867 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: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Mon, Apr 16, 2007 at 01:44:22PM +0100, Thiemo Seufer wrote: > Zhang Fuxin wrote: > > >> +cflags-$(CONFIG_CPU_LOONGSON2) += -march=r4600 -Wa,--trap > > > > > > I wonder why this is r4600. I heard the Loongson2 is MIPS IV compatible, > > > so r5000 / r8000 / r10000 would be better choices. > > > > Presently Loongson-2E is nearly MIPS III compatible(with some > > self-defined extensions), next version will be mips64 release2 compatible. > > I see. > > > -march=r4600 is inherited from loongson-1, -march=mips3 might be a > > better choice. > > Maybe. The 'mips3' maps to -march=r4000, it would assume more memory > latency and a slower integer divider then -march=r4600. I don't really have an issue with that since I see it as a temporary solution until gcc and binutils know about Loongson 2 specifics. Given the bit I know about the Loognson 2 processor architecture I would not expect a significant performance boost from trying different values for -march with current toolchains. Ralf