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: Jeff Davis <pgsql@j-davis.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-01-31T18:37:52Z
Lists: pgsql-hackers 
Hi,

On 2018-01-31 11:56:59 -0500, Robert Haas wrote:
> On Tue, Jan 30, 2018 at 5:57 PM, Andres Freund <andres@anarazel.de> wrote:
> > Given that we need a shared library it'll be best buildsystem wise if
> > all of this is in a directory, and there's a separate file containing
> > the stubs that call into it.
> >
> > I'm not quite sure where to put the code. I'm a bit inclined to add a
> > new
> > src/backend/jit/
> > because we're dealing with code from across different categories? There
> > we could have a pgjit.c with the stubs, and llvmjit/ with the llvm
> > specific code?
> 
> That's kind of ugly, in that if we eventually end up with many
> different parts of the system using JIT, they're all going to have to
> all put their code in that directory rather than putting it with the
> subsystem to which it pertains.

Yea, that's what I really dislike about the idea too.

> On the other hand, I don't really have a better idea.

I guess one alternative would be to leave the individual files in their
subsystem directories, but not in the corresponding OBJS lists, and
instead pick them up from the makefile in the jit shlib?  That might
better...

It's a bit weird because the files would be compiled when make-ing that
directory and rather when the jit shlib one made, but that's not too
bad.


> I'd definitely at least try to keep executor-specific considerations
> in a separate FILE from general JIT infrastructure, and make, as far
> as possible, a clean separation at the API level.

Absolutely.  Right now there's general infrastructure files (error
handling, optimization, inlining), expression compilation, tuple deform
compilation, and I thought to continue keeping the files separately just
like that.

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".