From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by oss.sgi.com id ; Tue, 9 Jan 2001 12:30:07 -0800 Received: from mx.mips.com ([206.31.31.226]:64478 "EHLO mx.mips.com") by oss.sgi.com with ESMTP id ; Tue, 9 Jan 2001 12:29:48 -0800 Received: from newman.mips.com (ns-dmz [206.31.31.225]) by mx.mips.com (8.9.3/8.9.0) with ESMTP id MAA02504; Tue, 9 Jan 2001 12:29:43 -0800 (PST) Received: from Ulysses (ulysses [192.168.236.13]) by newman.mips.com (8.9.3/8.9.0) with SMTP id MAA11181; Tue, 9 Jan 2001 12:29:40 -0800 (PST) Message-ID: <01c201c07a7b$696b9c40$0deca8c0@Ulysses> From: "Kevin D. Kissell" To: "Ralf Baechle" Cc: "Harald Koerfgen" , References: <20010109095438.A10683@paradigm.rfc822.org> <20010109162835.B4232@bacchus.dhis.org> <019901c07a72$94d19f00$0deca8c0@Ulysses> <20010109175416.A5383@bacchus.dhis.org> Subject: Re: MIPS32 patches breaking DecStation Date: Tue, 9 Jan 2001 21:33:12 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Sender: owner-linux-mips@oss.sgi.com Precedence: bulk Return-Path: X-Orcpt: rfc822;linux-mips-outgoing > > Yes, it's cute, but it relies on accidents of implementation to work, > > and could easily fail on other CPUs otherwise compatible with > > the R4000. In principle, such a branch might incur no delay at > > all on an advanced 64-bit processor. By all means, use it for > > the specific cases of the CPUs on which it is known to work, > > but it should not be used in "default" MIPS CP0 handlers. > > This behaviour of the R4000 branch is documented in the R4000 manual's > description of the pipeline. Yes, yes, like I said, use it whenever you see an R4000 PrID if you like. Just don't use it as the handler installed for a PrID not otherwise known to the kernel. Kevin K. From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <01c201c07a7b$696b9c40$0deca8c0@Ulysses> From: "Kevin D. Kissell" References: <20010109095438.A10683@paradigm.rfc822.org> <20010109162835.B4232@bacchus.dhis.org> <019901c07a72$94d19f00$0deca8c0@Ulysses> <20010109175416.A5383@bacchus.dhis.org> Subject: Re: MIPS32 patches breaking DecStation Date: Tue, 9 Jan 2001 21:33:12 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mips@oss.sgi.com Return-Path: To: Ralf Baechle Cc: Harald Koerfgen , linux-mips@oss.sgi.com Message-ID: <20010109203312.26za5K1dmk2x4vPG72SygEyJfxLWswiF9_tK423HqSg@z> > > Yes, it's cute, but it relies on accidents of implementation to work, > > and could easily fail on other CPUs otherwise compatible with > > the R4000. In principle, such a branch might incur no delay at > > all on an advanced 64-bit processor. By all means, use it for > > the specific cases of the CPUs on which it is known to work, > > but it should not be used in "default" MIPS CP0 handlers. > > This behaviour of the R4000 branch is documented in the R4000 manual's > description of the pipeline. Yes, yes, like I said, use it whenever you see an R4000 PrID if you like. Just don't use it as the handler installed for a PrID not otherwise known to the kernel. Kevin K.