Horton

Re: JIT compiling with LLVM v9.0

Jeff Davis <pgsql@j-davis.com>

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From: Jeff Davis <pgsql@j-davis.com>
To: Andres Freund <andres@anarazel.de>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-01-25T06:51:36Z
Lists: pgsql-hackers 
On Tue, Jan 23, 2018 at 11:20 PM, Andres Freund <andres@anarazel.de> wrote:
> Hi,
>
> I've spent the last weeks working on my LLVM compilation patchset. In
> the course of that I *heavily* revised it. While still a good bit away
> from committable, it's IMO definitely not a prototype anymore.

Great!

A couple high-level questions:

1. I notice a lot of use of the LLVM builder, for example, in
slot_compile_deform(). Why can't you do the same thing you did with
function code, where you create the ".bc" at build time from plain C
code, and then load it at runtime?
2. I'm glad you considered extensions. How far can we go with this in
the future? Can we have bitcode-only extensions that don't need a .so
file? Can we store the bitcode in pg_proc, simplifying deployment and
allowing extensions to travel over replication? I am not asking for
this now, of course, but I'd like to get the idea out there so we
leave room.

Regards,
     Jeff Davis

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".