[pdw]

The Game Boy doesn't use a Z80 though. It's based on a SM83 core, an obscure Sharp design.

[flohofwoe]

It's essentially a stripped Z80 without the DD-, ED- and FD-prefix instruction ranges. The core instruction block and CB-prefix range is (nearly) the same.

[busterarm]

See the other responses, but my comment was really suggesting that if LLVM barely supports Z80 then the GameBoy CPU is a hopeless lost cause.

[detaro]

True, but the instruction set is very close, so a Z80 implementation is a good starting point.