On Tuesday 15 April 2003 14:13, Tim Rowledge wrote:
Bryce Kampjes bryce@kampjes.demon.co.uk wrote:
There are a few things that would be nice purely for performance in an image change. Having a tag bit of 0 rather than 1 for integers would shave 3 instructions off simple arithmetic taking it down to 5 instructions on an x86.
.. and it would involve having the tag bit added to every OOP, meaning that one would have to mask out that bit for any indirection through that OOP.
Actually, you could just change the implementation of the "push instance variable 3" bytecode from
push 12[bx]
or whatever nastiness the x86 does, to
push 11[bx]
since you can think of the OOP as being address+1 and the offset as 4*3.
-- Jecel