RTL Layer Paralleling

[nick]

Greetings All,

After getting it some thought I've yet to see any real focus on making the RTL
layers or just the architectural backends parallel in nature. Is there a reason
for this as my assumption is that after reading parts of the x86 and rs6000 
backend code it's not needed. 

This seems to be the case as most of the profiling only really shows bottle necking
at least in my research at the gimple layer. Is this because little time has been
put into researching the RTL passes or it's just assumed to have no requirements
require to gimple and perhaps post GENERIC/pre GIMPLE passes?

Just curious as I've not a RTL or backend expert,

Nick