On Fri, 1 Feb 2002, Tim Rowledge wrote:

> iv) cleanup some header fields

What sorts of header field cleanups are under consideration?

My identityhash patches do a little refactor of the smalltalk-side of
things as far as the hashbits access.

>
> Plans: Any further proposals for image format affecting changes are
> needed as soon as possible; this is not something we want to do more
> than once.

Looking at an STSpace output...

About 310k objects in my image, 240k are stored compactly, saving about a
megabyte (6%) of the image size, but costing 5 bits in each header, and an
extra branch&table lookup on every findClassOf reference.

So, 6-7% space savings for 5 bits in the object header. Are they
good/bad/ugly.

Just a brainstorm, cause everyone seems to want header bits.


Scott