[squeak-dev] USe of isKindOf: is a crime against humanity

Andres Valloud avalloud at smalltalk.comcastbiz.net
Sun Sep 1 06:36:25 UTC 2013


Hey, let's use isKindOf: for exception handling!

... oh, wait...

On 8/31/13 23:35 , Andres Valloud wrote:
>> It's slow - it scans up a class tree.
>
> ... my favorite part of the slowness is that isKindOf: causes an
> unending sequence of megamorphic message sends which routinely need
> expensive lookups or large, much more complicated caches than "simple"
> PICs so the process is not overly slow.  And of course, since the
> isKindOf: code tends to be well refactored, there is effectively one
> send site for every one of those megamorphic messages in the whole
> image, which _ensures_ those send sites will be slow... ;).
>
> Andres.
>
>


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