[squeak-dev] Spur Identity Hash [was: The Trunk: System-cmm.689.mcz]

Chris Muller asqueaker at gmail.com
Fri Nov 14 16:56:41 UTC 2014

>> Anyway, something to be aware of -- anywhere we have true, false or
>> nil used in a hash calculation, now has a different hash in Spur vs.
>> Cog.  Maybe we should think about separating those objects' logical
>> "value" hash from their identityHash in trunk..?  That could be useful
>> when we move to 64-bit someday..
>  Remember that Spur has a common header format for both 32-bit and 64-bit
> versions, so in both there is a 22-bit identityHash and hence the
> identityHashes of all objects in a 64-bit Spur image bootstrapped from a
> 32-bit Spur image will be _unchanged_.  Convenient. So no need to worry.
> And it should be the case that a freshly bootstrapped 64-bit Spur image does
> not need to be rehashed to function properly.

Suprising that their identityHash needs to change for Spur but not to
go to 64-bit..

Wait, I thought one of the benefits of 64-bit was to finally increase
that small identityHash?

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