Re: Use compiler intrinsics for bit ops in hash

From: David Fetter <david(at)fetter(dot)org>
To: Jesse Zhang <sbjesse(at)gmail(dot)com>
Cc: PostgreSQL Development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Use compiler intrinsics for bit ops in hash
Date: 2020-02-27 05:56:40
Message-ID: 20200227055640.GL13804@fetter.org
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On Wed, Feb 26, 2020 at 09:12:24AM +0100, David Fetter wrote:
> On Fri, Jan 31, 2020 at 04:59:18PM +0100, David Fetter wrote:
> > On Wed, Jan 15, 2020 at 03:45:12PM -0800, Jesse Zhang wrote:
> > > On Tue, Jan 14, 2020 at 2:09 PM David Fetter <david(at)fetter(dot)org> wrote:
> > > > > The changes in hash AM and SIMPLEHASH do look like a net positive
> > > > > improvement. My biggest cringe might be in pg_bitutils:
> > > > >
> > > > > 1. Is ceil_log2_64 dead code?
> > > >
> > > > Let's call it nascent code. I suspect there are places it could go, if
> > > > I look for them. Also, it seemed silly to have one without the other.
> > > >
> > >
> > > While not absolutely required, I'd like us to find at least one
> > > place and start using it. (Clang also nags at me when we have
> > > unused functions).
> >
> > Done in the expanded patches attached.
>
> These bit-rotted a little, so I've updated them.

05d8449e73694585b59f8b03aaa087f04cc4679a broke this patch set, so fix.

Best,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778

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Attachment Content-Type Size
v6-0001-de-long-ify.patch text/x-diff 56.7 KB
v6-0002-Spread-bitutils-into-hashing.patch text/x-diff 11.4 KB
v6-0003-Reduced-operations-in-floor_log2.patch text/x-diff 1.4 KB

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