| From: | Andres Freund <andres(at)anarazel(dot)de> |
|---|---|
| To: | Yura Sokolov <y(dot)sokolov(at)postgrespro(dot)ru> |
| Cc: | Ranier Vilela <ranier(dot)vf(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> |
| Subject: | Re: Bug in huge simplehash |
| Date: | 2021-08-13 12:14:31 |
| Message-ID: | 20210813121431.bykwkdmttbwulqib@alap3.anarazel.de |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 2021-08-13 14:40:08 +0300, Yura Sokolov wrote:
> Ranier Vilela писал 2021-08-13 14:12:
> > Em sex., 13 de ago. de 2021 às 07:15, Andres Freund
> > <andres(at)anarazel(dot)de> escreveu:
> > > Personally I find it more obvious to understand the intended
> > > behaviour
> > > with ~0 (i.e. all bits set) than with a width truncation.
> >
> > https://godbolt.org/z/57WcjKqMj
> > The generated code is identical.
>
> I believe, you mean https://godbolt.org/z/qWzE1ePTE
I don't think the choice of instructions matters. This is called around
creation and resizing - the other costs are several orders of magnitude
more expensive than determining the mask.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Julien Rouhaud | 2021-08-13 12:32:56 | Re: Shared memory size computation oversight? |
| Previous Message | Marek Szuba | 2021-08-13 11:54:52 | [PATCH] Native spinlock support on RISC-V |