Horton

Re: JIT compiling with LLVM v9.0

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Thomas Munro <thomas.munro@enterprisedb.com>, Jeff Davis <pgsql@j-davis.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-01-31T18:34:36Z
Lists: pgsql-hackers 
Hi,

On 2018-01-31 11:53:25 -0500, Robert Haas wrote:
> On Wed, Jan 31, 2018 at 10:22 AM, Peter Eisentraut
> <peter.eisentraut@2ndquadrant.com> wrote:
> > On 1/30/18 21:55, Andres Freund wrote:
> >> I'm open to changing my mind on it, but it seems a bit weird that a
> >> feature that relies on a shlib being installed magically turns itself on
> >> if avaible. And leaving that angle aside, ISTM, that it's a complex
> >> enough feature that it should be opt-in the first release... Think we
> >> roughly did that right for e.g. parallellism.
> >
> > That sounds reasonable, for both of those reasons.
> 
> The first one is a problem that's not going to go away.  If the
> problem of JIT being enabled "magically" is something we're concerned
> about, we need to figure out a good solution, not just disable the
> feature by default.

That's a fair argument, and I don't really have a good answer to it. We
could have a jit = off/try/on, and use that to signal things? I.e. it
can be set to try (possibly default in version + 1), and things will
work if it's not installed, but if set to on it'll refuse to work if not
enabled. Similar to how huge pages work now.

Greetings,

Andres Freund

Commits

  1. Improve JIT docs.

  2. Add documentation for the JIT feature.

  3. Add EXPLAIN support for JIT.

  4. Add inlining support to LLVM JIT provider.

  5. JIT tuple deforming in LLVM JIT provider.

  6. Add FIELDNO_* macro designating offset into structs required for JIT.

  7. Add expression compilation support to LLVM JIT provider.

  8. Expand list of synchronized types and functions in LLVM JIT provider.

  9. Add helpers for emitting LLVM IR.

  10. Basic planner and executor integration for JIT.

  11. Debugging and profiling support for LLVM JIT provider.

  12. Support for optimizing and emitting code in LLVM JIT provider.

  13. Add file containing extensions of the LLVM C API.

  14. Basic JIT provider and error handling infrastructure.

  15. Add configure infrastructure (--with-llvm) to enable LLVM support.

  16. Add C++ support to configure.

  17. Add PGAC_PROG_VARCC_VARFLAGS_OPT autoconf macro.

  18. Fix VM buffer pin management in heap_lock_updated_tuple_rec().

  19. Allow tupleslots to have a fixed tupledesc, use in executor nodes.

  20. Expression evaluation based aggregate transition invocation.

  21. Perform slot validity checks in a separate pass over expression.

  22. Rely on executor utils to build targetlist for DML RETURNING.

  23. Refer to OS X as "macOS", except for the port name which is still "darwin".