Re: [HACKERS] [PATCH v4] Avoid manual shift-and-test logic in AllocSetFreeIndex

[Jeremy Kerr]

Hi Greg,

Thanks for the benchmark app, thought I'd pitch in with some ppc 
results:

>                  clz 1.530s
>         lookup table 1.720s
>           float hack 4.424s
>             unrolled 5.280s
>               normal 5.369s

POWER5+:
                 clz 2.046s
        lookup table 2.188s
          float hack 7.786s
            unrolled 6.353s
              normal 7.033s

POWER6:
                 clz 1.063s
        lookup table 1.199s
          float hack 3.575s
            unrolled 2.290s
              normal 3.456s

Cheers,


Jeremy


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