Re: [announce] [patch] ultra-scalable O(1) SMP and UP scheduler

Ingo Molnar (mingo@elte.hu)
Sun, 6 Jan 2002 05:19:11 +0100 (CET)


On Sun, 6 Jan 2002, Alan Cox wrote:

> There are better algorithms than the branching one already. You can do
> it a 32bit one with a multiply shift and 6 bit lookup if your multiply
> is ok, or for non superscalar processors using shift and adds.
>
> 64bit is 32bit ffz(x.low|x.high) and a single bit test

ok - i wasnt thinking straight. as few branches as possible should be the
way to go, no BTB will help such functions so branches must be reduced.

Ingo

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