Created attachment 652449 [details] [diff] [review]
Bug 675381 added some code to prevent blocked register allocation at phis. This hurts the loop in 3d-cube's DrawLine; the code Ion currently generates for the loop is atrocious. The patch reduces the instruction count for that loop from 43 to 29 and reduces the benchmark time from 12.2 to 11.7 ms.
I will fuzz this for a few hours before landing, just in case I'm missing something, but I'm pretty sure this patch is safe now.
This didn't turn out to be a large 3d-cube win on AWFY, but it helped ss-nsieve, navier-stokes and gaussian-blur.