Reaching definitions on Machine IR post register allocation

Hi Venu,
This is what I used: It fails check-llvm because extra register classes are generated, which changes what the scheduling algorithm does. I added a non-allocatable register class for the new registers, but maybe removing it altogether would be better. I never explored this patch any further, so I'm not sure how well it works if you ignore the lit mismatches.


Hi Krzysztof,

Thanks for the pointer to the patch. I will try it out.

My runtime error appears even when I build the RDF graph and just do the RDF liveness analysis without invoking RDF copy propagation. It seems that some later pass downstream is doing something wrong after the liveness information is recomputed. This error appears even when I exclude my patch for the X86 partial register definition issue. I am trying to narrow it down. It is taking time to figure out which pass is introducing the problem.

Once again, many thanks for your pointer.