Performance comparison, ULE vs 4BSD and AMD64 vs i386

David O'Brien obrien at
Wed Feb 25 10:32:37 PST 2004

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?


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 at

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