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help / color / mirror / Atom feedFrom: John Naylor <[email protected]>
To: David Rowley <[email protected]>
Cc: Andres Freund <[email protected]>
Cc: Chao Li <[email protected]>
Cc: PostgreSQL Developers <[email protected]>
Subject: Re: More speedups for tuple deformation
Date: Sat, 31 Jan 2026 13:01:44 +0700
Message-ID: <CANWCAZYkQ+hYyr9L1rWJaKPKHZP__F1e1nCb6_d++ogB5bNEaw@mail.gmail.com> (raw)
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On Sat, Jan 31, 2026 at 10:45 AM David Rowley <[email protected]> wrote:
> On Sat, 31 Jan 2026 at 15:48, John Naylor <[email protected]> wrote:
> > pg_rightmost_one_pos32(~((uint32) bits[bytenum]))
>
> I'd rather handle that in a single byte as the fallback path in that
> function requires byte-at-a-time processing.
I spot checked some less common animals in the buildfarm and i686,
ppc64le, riscv64, loongarch64, and s390x all have the builtin. Of
these, only riscv64 seems to lack a single instruction implementation.
It's good to keep the old fallback path around just in case, but I
doubt a new fallback would get any coverage at all.
--
John Naylor
Amazon Web Services
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Subject: Re: More speedups for tuple deformation
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