Messages in this thread | | | Subject | Re: [announce] [patch] ultra-scalable O(1) SMP and UP scheduler | Date | Sun, 6 Jan 2002 02:30:54 +0000 (GMT) | From | Alan Cox <> |
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> we can do 32-bit ffz by doing 4x 8-bit ffz's though:
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
I can dig out the 32bit one if need be (its from a NetBSD mailing list) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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