Re: [Squeak-VMdev] An object format proposal

[Anthony H. <ajh...@ya...>]

One thing I forgot is the isLarge flag has to be repeated in the -8
word, so when going to the next object you know if the header is two
or three words.  So here's the format again.

 -8	isLarge flag, n if large (this field does not exist if not large)
  4	isLarge flag, identityHash, other flags, isOops flag, n if small
  0	class pointer, gc flags (in low 2 bits)
  4	(for class objects only) primitive type, isBytes & isWeak flags, m
  ..
  n

isLarge can be the high bit or the low bit, it just has to be the same
in both words.  Also, the two low bits of class oop can be used for
flags, and I added "other" flags for immutable or whatever we decide.

Cheers,
Anthony


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