[LLVMdev] Simpler subreg ops in machine code IR

[Rafael Espindola]

> 1. copyRegToReg() won't be able to use register classes to pick a copy opcode. For instance, an XMM register will no longer be copied by MOVSS or MOVSD. Given just the physical register, MOVAPS will be used. Is that a problem?

I haven't had time to really look into it, but have been playing
around with the idea that instead of two register classes copyRegToReg
and some of the load and store callbacks should take a MVT. This
should be enough, no? Anyway, I like anything that makes the backend
interface simpler :-)

Thanks a lot for working on this.

Cheers,
-- 
Rafael Ávila de Espíndola