Re: define pg_structiszero(addr, s, r) - Mailing list pgsql-hackers

From David Rowley
Subject Re: define pg_structiszero(addr, s, r)
Date
Msg-id CAApHDvp2qcO_0=FZy6PHPZKsRgOUuEXqdCiki3bCNweex9-_Uw@mail.gmail.com
Whole thread Raw
In response to Re: define pg_structiszero(addr, s, r)  (Bertrand Drouvot <bertranddrouvot.pg@gmail.com>)
List pgsql-hackers
On Wed, 6 Nov 2024 at 13:52, Michael Paquier <michael@paquier.xyz> wrote:
>
> On Wed, Nov 06, 2024 at 01:38:50PM +1300, David Rowley wrote:
> > We could just write it that way and leave it up to the compiler to
> > decide whether to use SIMD or not. Going by [1], gcc with -O2 uses
> > SIMD instructions from 14.1 and clang with -O2 does it from version
> > 8.0.0. gcc 14.1 was release in May 2024, so still quite new. It'll be
> > quite a bit older once PG18 is out.  Using the bitwise-OR method, more
> > and more people will benefit as gcc14.1 and beyond becomes more
> > mainstream.
> >
> > Clang 8.0.0 is from March 2019, so quite old already.
>
> Okay, WFM to keep things the way they are in the patch.

I'm not sure if I'm clear on what works for you.  The latest patch I
saw did 1 size_t per iteration. Are you saying we should do just
size_t per loop? or we should form the code in a way that allows the
compiler to use SIMD instructions?

David



pgsql-hackers by date:

Previous
From: Amit Langote
Date:
Subject: Re: doc fail about ALTER TABLE ATTACH re. NO INHERIT
Next
From: jian he
Date:
Subject: Re: Wrong result when enable_partitionwise_join is on if collation of PartitionKey and Column is different.