From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: In-Reply-To: <20070412202226.GA9388@lixom.net> References: <20070410111508.GA2969@localhost.localdomain> <200704121501.34311.arnd@arndb.de> <981B07C8-D35B-4581-8FC7-DCA58430A081@kernel.crashing.org> <200704121926.03723.arnd@arndb.de> <04335E0C-3963-4849-BEC7-DC9DF3E3280F@kernel.crashing.org> <20070412200431.GA9067@lixom.net> <20070412202226.GA9388@lixom.net> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <5152cb179d32c343cfff81c414dc3bd1@kernel.crashing.org> From: Segher Boessenkool Subject: Re: [Cbe-oss-dev] [RFC, PATCH] selection of CPU optimization Date: Thu, 12 Apr 2007 22:22:30 +0200 To: olof@lixom.net (Olof Johansson) Cc: linuxppc-dev list , Arnd Bergmann , cbe-oss-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , >> Except that's not in any public GCC version yet. Well, >> two weeks ago it wasn't... >> >> Note that specifying an unknown -mcpu/tune= is an error, >> not a warning or totally ignored. > > Correct, it's not upstream yet. It will be at some point, and in > general > people who have access to hardware also have access to a toolchain that > has it. > > So, leave it open, or use 970 settings for now to keep Segher happy. -mcpu=970 would be wrong (although it should work in this specific case). -mcpu=powerpc64 is better. -mtune=970 wouldn't make any sense. It's not about "keeping me happy", it's about doing the Right Thing(tm). Don't fight the toolchain, work with it. Segher