If you track source-changes, you'll notice I just submitted a
large change to the powerpc code.

The major effect of this is that on MPC6XX (G3, G4, 60x) systems
the vector pages are no longer used for temporary storage.   So
they can now be checked to make sure nothing is writing in them
(as would be done on a null pointer dereference).

Note that global variable references take two instructions (to
load the two 16-bit halves of the address) and loading from the
cpu_info structure also takes two instructions (since the address
to that structure is always in SPRG0).  But multiple references
will be cheaper since the value of SPRG0 will be cached in a
register.

A lot of the uniprocessor/multiprocessor differences are now gone
and things operate the same for either mode.  Also, much more code
is now common than before.

-- 
Matt Thomas               Internet:   matt@3am-software.com
3am Software Foundry      WWW URL:    http://www.3am-software.com/bio/matt/
Cupertino, CA             Disclaimer: I avow all knowledge of this message