I had to post the following quote from this week's Perl.com's This week in Perl 6 report:

"Dan reported that examples/assembly/mops_p.pasm was running slower with JIT optimization than without under OSX, which doesn't seem right. Daniel Grunblatt pointed out that JIT cores that don't optimize many opcodes will always be slower than a Computed Goto (CG) core and there aren't many optimized opcodes for the PPC architecture. Bruce Gray pointed Dan at an introduction to PPC assembler in case Dan wanted to add to the score of optimizations. Anyone else is interested could take a look too, kudos awaits the heroic implementer."