(In reply to comment #12)
> Created attachment 105630 [details] [review] [review]
> another debugging patch
> 
> Ok, it looks like the problem is that node 0's q_total is bogus, which means
> it never even gets considered for optimistic coloring. To help me figure out
> why this is, can you apply this patch to master (not on top of the other
> patch) and tell me the output of the piglit test now?

On (In reply to comment #12)
> Created attachment 105630 [details] [review] [review]
> another debugging patch
> 
> Ok, it looks like the problem is that node 0's q_total is bogus, which means
> it never even gets considered for optimistic coloring. To help me figure out
> why this is, can you apply this patch to master (not on top of the other
> patch) and tell me the output of the piglit test now?

I'm not sure if this matters, but r300g pre-allocates the input registers
before calling ra_allocate_no_spills().