| From: | Nathan Bossart <nathandbossart(at)gmail(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | John Naylor <john(dot)naylor(at)enterprisedb(dot)com>, Andres Freund <andres(at)anarazel(dot)de>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: use ARM intrinsics in pg_lfind32() where available |
| Date: | 2022-08-27 22:15:02 |
| Message-ID: | 20220827221502.GB15951@nathanxps13 |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Sat, Aug 27, 2022 at 05:18:34PM -0400, Tom Lane wrote:
> In short, I think the critical part of 0002 needs to look more like
> this:
>
> +#elif defined(__aarch64__) && defined(__ARM_NEON)
> +/*
> + * We use the Neon instructions if the compiler provides access to them
> + * (as indicated by __ARM_NEON) and we are on aarch64. While Neon support is
> + * technically optional for aarch64, it appears that all available 64-bit
> + * hardware does have it. Neon exists in some 32-bit hardware too, but
> + * we could not realistically use it there without a run-time check,
> + * which seems not worth the trouble for now.
> + */
> +#include <arm_neon.h>
> +#define USE_NEON
> ...
Thank you for the analysis! I'll do it this way in the next patch set.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Thomas Munro | 2022-08-27 22:39:09 | Re: use ARM intrinsics in pg_lfind32() where available |
| Previous Message | Nathan Bossart | 2022-08-27 22:12:34 | Re: use ARM intrinsics in pg_lfind32() where available |