[Vm-dev] Direct object pointers vs indirect ones pros and cons
David T. Lewis
lewis at mail.msen.com
Fri Nov 12 20:15:26 UTC 2010
On Fri, Nov 12, 2010 at 02:03:44PM -0500, David T. Lewis wrote:
> If you want to measure the effects of an extra level of indirection at a
> low level, you may want to try hacking the MemoryAccess slang version of
> the C macros.
Oops, sorry, I didn't notice that Bert had already done this experiment
and posted the results:
On Fri, Nov 12, 2010 at 04:44:42PM +0100, Bert Freudenberg wrote:
> I don't think this can be realistically simulated inside Squeak. But
> possibly you could change the macros in sqMemoryAccess.h t o fake an
> object table access?
> I just tried that. Using tinyBenchmarks, byte code performance drops
> to 63% and sends to 78%.
> Now declaring that variable volatile might be overkill as it prevents all
> caching, but I couldn't quite figure out a more realistic declaration.
> - Bert -
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