Re: always use runtime checks for CRC-32C instructions

On Tue, Oct 31, 2023 at 03:42:33PM -0400, Tom Lane wrote:
> The one machine using slicing-by-8 where there might be a better
> alternative is arowana, which is CentOS 7 with a pretty ancient gcc
> version.  So I reject the idea that slicing-by-8 is an appropriate
> baseline for comparisons.  There isn't anybody who will see an
> improvement over current behavior: in the population of interest,
> just about all platforms are using CRC instructions with or without
> a runtime check.

I only included the slicing-by-8 benchmark to demonstrate that 1) the CRC
computations are a big portion of that pg_waldump -z command and that 2)
the CRC instructions provide significant performance gains.

-- 
Nathan Bossart
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