Horton

Re: JIT compiling with LLVM v9.0

David Fetter <david@fetter.org>

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From: David Fetter <david@fetter.org>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Jeff Davis <pgsql@j-davis.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2018-01-30T21:57:06Z
Lists: pgsql-hackers 
On Tue, Jan 30, 2018 at 01:46:37PM -0500, Robert Haas wrote:
> On Mon, Jan 29, 2018 at 1:40 PM, Andres Freund <andres@anarazel.de> wrote:
> > It's an optional dependency, and it doesn't increase build time
> > that much... If we were to move the llvm interfacing code to a
> > .so, there'd not even be a packaging issue, you can just package
> > that .so separately and get errors if somebody tries to enable
> > LLVM without that .so being installed.
> 
> I suspect that would be really valuable.  If 'yum install
> postgresql-server' (or your favorite equivalent) sucks down all of
> LLVM,

As I understand it, LLVM is organized in such a way as not to require
this.  Andres, am I understanding correctly that what you're using
doesn't require much of LLVM at runtime?

> some people are going to complain, either because they are
> trying to build little tiny machine images or because they are
> subject to policies which preclude the presence of a compiler on a
> production server.  If you can do 'yum install postgresql-server'
> without additional dependencies and 'yum install
> postgresql-server-jit' to make it go faster, that issue is solved.

Would you consider it solved if there were some very small part of the
LLVM (or similar JIT-capable) toolchain added as a dependency, or does
it need to be optional into a long future?

> Unfortunately, that has the pretty significant downside that a lot of
> people who actually want the postgresql-server-jit package will not
> realize that they need to install it, which sucks.

It does indeed.

Best,
David.
-- 
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778

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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".