[LLVMdev] How to specify the arm subtarget instruction set in a pass or an arm-backend?

[Shellkunchik]

Dear developers!

I have one problem and two options for its solution:
•       I can make a simple pass which will specify the subtarget instruction set (ARM or Thumb) for a particular instruction (or a basic block) LLVM intermediate representation
OR
•       I can add a special pass to arm backend which will do the same (specify subtarget instruction set (ARM or Thumb) for a particular instruction or basic block LLVM intermediate representation)

Can you tell me which way is easier and describe to me how to code it?

Sincerely yours,

Leonid.