Horton

Re: WIP: Faster Expression Processing and Tuple Deforming (including JIT)

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Heikki Linnakangas <hlinnaka@iki.fi>, Doug Doole <ddoole@salesforce.com>
Date: 2016-12-06T20:18:29Z
Lists: pgsql-hackers 
On 2016-12-06 15:13:21 -0500, Robert Haas wrote:
> Presumably this is going to need to be something that a user can get
> via yum install <blah> or apt-get install <blah> on common systems.

Right. apt-get install llvm-dev (or llvm-3.9-dev or such if you want to
install a specific version), does the trick here.

It's a bit easier to develop with a hand compiled version, because then
LLVM adds a bootloads of asserts to its IR builder, which catches a fair
amount of mistakes. Nothing you'd run in production though (just like
you don't use a cassert build...).


> I wonder how feasible it would be to make this a run-time dependency
> rather than a compile option.  That's probably overcomplicating
> things, but...

I don't think that's feasible at all unfortunately - the compiler IR
(which then is JITed by LLVM) is generated via another C API.  We could
rebuild that one, but that'd be a lot of work.

Andres

Commits

  1. Improve performance of ExecEvalWholeRowVar.

  2. Remove unreachable code in expression evaluation.

  3. Faster expression evaluation and targetlist projection.

  4. Avoid syntax error on platforms that have neither LOCALE_T nor ICU.

  5. Add configure test to see if the C compiler has gcc-style computed gotos.

  6. Improve regression test coverage for TID scanning.

  7. Improve expression evaluation test coverage.

  8. Fix two errors with nested CASE/WHEN constructs.