128bit binary instruction format?

Hi,

The ISA I am working on is always encoded in 128bit binary format. I find that getBinaryCodeForInst() only return at most 64bit Encoding.
So, I think the proper way to encode the instructions is to write the XXXMCCodeEmitter by myself instead of automatic generation. right?

Is there any guideline/suggestion on how to write the XXXMCCodeEmitter using current LLVM infrastructure? I want to use the existing
classes/functions in backend infrastructure as much as I can.

Thanks!
Ruiling

If you want an example of a backend that doesn't use getBinaryCodeForInst(), you can look at the x86 backend. That said, the right approach probably depends on what exactly you mean by 128bit binary format...

-Eli