Re: aio is unlikely

[Jeff Garzik]

Nick Piggin wrote:
> Aside from using branch constructs or hints that help the predictor
> guess the right way... I think gcc will move unlikely paths right past
> the end of the "likely" fastpath, so it can increase code size and be
> somewhat suboptimal in terms of icache usage.

Thanks for the reminder.  GCC definitely does code movement.

ISTR the code movement might even be "extreme", once the unit-at-a-time 
support arrived, placing "cold" code at the end of the compiled module.

	Jeff


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