[LLVMdev] Eliminating copies between overlapping register classes

[Jakob Stoklund Olesen]

On Feb 23, 2012, at 9:50 AM, Tom Stellard <thomas.stellard at amd.com> wrote:

> Thanks for the debugging type, I caught my mistake.  Class A wasn't
> actually a subset of B. The definitions were actually like this:
> 
> A = [R0, R1, R2, ... R128, CC]
> 
> B = [RO, R1, R2, ... R128,
>     T0, T1, T2, … T128

If you upgrade to trunk, TableGen will automatically synthesize a register class representing the intersection.

/jakob