Re: A population of population counts

On Sun, May 8, 2016 at 7:46 PM, Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> My aim with this thread was mainly reducing code duplication and
> needless code: perhaps at least the other ideas in the attached
> sketch, namely using ffs instead of the rightmost_one_pos table loop
> and consolidation of popcount into a reusable API (without trying to
> get hardware support) could be worth polishing for the next CF?
> Annoyingly, it seems Windows doesn't have POSIX/SUSv2 ffs, though
> apparently it can reach that instruction with MSVC intrinsic
> _BitScanReverse or MingW __builtin_ffs.

I think my_log2() is the same thing as one of ffs() and fls() - I can
never keep those straight.  It seems like it wouldn't he hard to clean
things up at least that much.

-- 
Robert Haas
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