Bugzilla

perf says most of the time (I'm eyeballing > 75%) is being spent in the register allocator, with 33% in resolveControlFlow alone.

perf says most of the time (I'm eyeballing > 75%) is being spent in the register allocator, with 33% in resolveControlFlow alone.

There's a four-deep loop in that function, starting around line 2029 (one of the loops is hidden inside rangeFor()), that's probably the problem.

The performance profile doesn't really speak to the memory growth, of course, but this loop introduces moves and it looks like it introduces one for each iteration of the level-3 loop.