[COMMIT] GC Speedup

I've just committed some changes tonight that improved performance
on the GC-heavy tests in examples/benchmarks/ by about 8%.

Results on each of the GC benchmark tests are, scaled against 1.0 as the
old version, are:
                                old     new
gc_alloc_new.pbc                1.000   0.969
gc_alloc_reuse.pbc              1.000   0.957
gc_generations.pbc              1.000   0.899
gc_header_new.pbc               1.000   0.991
gc_header_reuse.pbc             1.000   0.871
gc_waves_headers.pbc            1.000   0.867
gc_waves_sizeable_data.pbc      1.000   0.987
gc_waves_sizeable_headers.pbc   1.000   0.855

Overall:
old 1.000
new 0.925

Details of what were done to accomplish this can be found in my email to
the cvs-parrot list. It was pretty much 4 or 5 distinct things that each
gave a couple percentage points' improvement.

Thanks,
Mike Lambert

• [COMMIT] GC Speedup by Mike Lambert
• Re: [COMMIT] GC Speedup by Peter Gibbs
• Re: [COMMIT] GC Speedup by Mike Lambert
• Re: [COMMIT] GC Speedup by Peter Gibbs
• Re: [COMMIT] GC Speedup by Mike Lambert
• Re: [COMMIT] GC Speedup by Nicholas Clark
• Re: [COMMIT] GC Speedup by Mike Lambert