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From: Arnd Bergmann <arnd@arndb.de>
To: cbe-oss-dev@ozlabs.org
Subject: Re: [Cbe-oss-dev] [patch 3/3] cell: prevent alignment interrupt on
	local store
Date: Thu, 12 Apr 2007 20:43:38 +0200
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Cc: linuxppc-dev@ozlabs.org, Olaf Hering <olaf@aepfle.de>
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On Thursday 12 April 2007, Olaf Hering wrote:
> How much will this impact performance on a 970, 74xx or POWER6 if
> everything gets compiled with '--mcpu=$cell', compared to what is used
> today? One gets at least altivec that way.

Building with -mcpu=cell won't work on 970 or g4, because that enables
a few extra instructions that were not present in the older cpus.

If you know you want to build with altivec (i.e. not run on power4 or
older), then '-m32 -mcpu=7450 -mtune=cell' or '-m64 -mcpu=970 -mtune=cell'
would be a reasonable thing to try.

	Arnd <><