Horton

Re: JIT compiling with LLVM v11

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2018-03-12T17:05:01Z
Lists: pgsql-hackers 
On 2018-03-12 11:21:36 -0400, Peter Eisentraut wrote:
> On 3/11/18 14:25, Andres Freund wrote:
> >> It's perhaps a bit confusing that some of the jit_* settings take effect
> >> at plan time and some at execution time.  At the moment, this mainly
> >> affects me reading the code ;-), but it would also have some effect on
> >> prepared statements and such.
> > Not quite sure what you mean?
> 
> I haven't tested this, but what appears to be the case is that
> 
> SET jit_above_cost = 0;
> PREPARE foo AS SELECT ....;
> SET jit_above_cost = infinity;
> EXECUTE foo;
> 
> will use JIT, because jit_above_cost applies at plan time, whereas
> 
> SET jit_expressions = on;
> PREPARE foo AS SELECT ....;
> SET jit_expressions = off;
> EXECUTE foo;
> 
> will *not* use JIT, becaue jit_expressions applies at execution time.

Right.  It'd be easy to change that so jit_expressions=off wouldn't have
an effect there anymore.  But I'm not sure we want that? I don't have a
strong feeling about this, except that I think jit_above_cost etc should
apply at plan, not execution time.

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".