Re: Enabling Checksums

On Fri, Apr 5, 2013 at 9:39 PM, Ants Aasma <ants@cybertec.at> wrote:
> Unless somebody tells me not to waste my time I'll go ahead and come
> up with a workable patch by Monday.

And here you go. I decided to be verbose with the comments as it's
easier to delete a comment to write one. I also left in a huge jumble
of macros to calculate the contents of a helper var during compile
time. This can easily be replaced with the calculated values once we
settle on specific parameters.

Currently only x86-64 is implemented. 32bit x86 would be mostly a
copy-and-paste job, replacing 64bit pointer registers with 32bit ones.
For other platforms the simplest way would be to use a vectorizing
compiler on the generic variant. -funroll-loops -ftree-vectorize is
enough on gcc.

Quick bench results on the worst case workload:
master no checksums: tps = 15.561848
master with checksums: tps = 1.695450
simd checksums: tps = 14.602698

Regards,
Ants Aasma
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