[LLVMdev] Storage-Only Register Class?

[Tim Northover]

> Is there a way to define a register class that is storage-only?  I want to
> have an i8 register class that I can use for loads/stores/converts, but that
> does not support arithmetic.

What springs to mind is setLoadExtAction and setTruncStoreAction, if
arithmetic has to be done in a larger type anyway. I *think* LLVM
should give you a bunch of ANY_EXT loads to a legal type if you set
those properly, which you can match with whatever instructions you
want.

Or is there some oddity of your situation that means that doesn't work?

Cheers.

Tim.