On Wed, Feb 07, 2024 at 01:48:57PM -0800, Andres Freund wrote:
> Now, in most cases this won't matter, the sorting isn't performance
> critical. But I don't think it's a good idea to standardize on a generally
> slower pattern.
>
> Not that that's a good test, but I did quickly benchmark [1] this with
> intarray. There's about a 10% difference in performance between using the
> existing compASC() and one using
> return (int64) *(const int32 *) a - (int64) *(const int32 *) b;
>
>
> Perhaps we could have a central helper for this somewhere?
Maybe said helper could use __builtin_sub_overflow() and fall back to the
slow "if" version only if absolutely necessary. The assembly for that
looks encouraging, but I still need to actually test it...
--
Nathan Bossart
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