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Date:      Wed, 25 Feb 2004 10:32:34 -0800
From:      "David O'Brien" <obrien@FreeBSD.org>
To:        Kenneth Culver <culverk@sweetdreamsracing.biz>
Cc:        "'freebsd-amd64@FreeBSD.org'" <freebsd-amd64@FreeBSD.org>
Subject:   Re: Performance comparison, ULE vs 4BSD and AMD64 vs i386
Message-ID:  <20040225183234.GG7567@dragon.nuxi.com>
In-Reply-To: <20040225110754.hcogcccokg84k44k@www.sweetdreamsracing.biz>
References:  <1077658664.92943.15.camel@.rochester.rr.com> <20040225110754.hcogcccokg84k44k@www.sweetdreamsracing.biz>

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On Wed, Feb 25, 2004 at 11:07:54AM -0500, Kenneth Culver wrote:
> The buildworld problem could just be because it takes longer for the 
> compiler to
> generate amd64 code. In fact, I'm almost willing to bet that's the case 
> since
> amd64 has 2x the GPR's that x86 does. It's likely that it's harder to 
> optimize
> for it. Does anyone who knows compilers care to comment?

s/harder/slower/

It is defineately easier to optimize for amd64 because if its increased #
of registers.  But I'm not sure even "slower" is a valid claim -- on the
i386 the compiler has to do a lot of time figuring out the best way to do
the spill code (when, where).

-- 
-- David  (obrien@FreeBSD.org)



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