Re: Special-case executor expression steps for common combinations

Daniel Gustafsson <daniel@yesql.se>

From: Daniel Gustafsson <daniel@yesql.se>

To: Andreas Karlsson <andreas@proxel.se>

Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>

Date: 2024-09-10T08:54:36Z

Lists: pgsql-hackers

Commits

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Add special case fast-paths for strict functions
- d35d32d7112b 18.0 landed
Replace EEOP_DONE with special steps for return/no return
- 8dd7c7cd0a26 18.0 landed

Attachments

v3-0001-Replace-EEOP_DONE-with-special-steps-for-return-n.patch (application/octet-stream) patch v3-0001
v3-0002-Add-special-case-fast-paths-for-strict-functions.patch (application/octet-stream) patch v3-0002

> On 22 Jul 2024, at 23:25, Andreas Karlsson <andreas@proxel.se> wrote:
> 
> I have bench marked the two patches now and failed to measure any speedup or slowdown from the first patch (removing return) but I think it is a good idea anyway.
> 
> For the second patch (optimize strict) I managed to measure a ~1% speed up for the following query "SELECT sum(x + y + 1) FROM t;" over one million rows.

That's expected, this is mostly about refactoring the code to simplifying the
JITed code (and making tiny strides towards JIT expression caching).

> I would say both patches are ready for committer modulo my proposed style fixes.

I am a bit wary about removing the out_error label and goto since it may open
up for reports from static analyzers about control reaching the end of a
non-void function without a return. The other change has been incorporated.

The attached v3 is a rebase to handle executor changes done since v2, with the
above mentioned fix as well.  If there are no objections I think we should
apply this version.

--
Daniel Gustafsson