Re: Prefetches in buffer_zero_*

[Richard Henderson]

On 7/22/21 12:02 AM, Dr. David Alan Gilbert wrote:
> Hi Richard,
>    I think you were the last person to fiddle with the prefetching
> in buffer_zero_avx2 and friends; Joe (cc'd) wondered if explicit
> prefetching still made sense on modern CPUs, and that their hardware
> generally figures stuff out better on simple increments.
>
>    What was your thinking on this, and did you actually measure
> any improvement?

Ah, well, that was 5 years ago so I have no particular memory of this.  It wouldn't 
surprise me if you can't measure any improvement on modern hardware.

Do you now measure an improvement with the prefetches gone?


r~