Horton

Re: JIT compiling with LLVM v12.2

Thomas Munro <thomas.munro@enterprisedb.com>

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From: Thomas Munro <thomas.munro@enterprisedb.com>
To: Andres Freund <andres@anarazel.de>
Cc: Stephen Frost <sfrost@snowman.net>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2018-03-21T23:07:57Z
Lists: pgsql-hackers 
On Thu, Mar 22, 2018 at 11:46 AM, Andres Freund <andres@anarazel.de> wrote:
> On 2018-03-22 11:36:47 +1300, Thomas Munro wrote:
>> Not sure if we'll want to try to actively identify and avoid known
>> buggy versions or not?
>
> I'm currently not inclined to invest a lot of effort into it, besides
> trying to get the bug fixed.
>
> A possible testcase would be to call
> createLocalIndirectStubsManagerBuilder() and report an error if it
> returns nullptr. But that'd fail once the bug is fixed, because we don't
> actually *need* that functionality, it's just that LLVM instantiates the
> stub manager unconditionally for some reason.

So how about we test createLocalIndirectStubsManagerBuilder(), and if
it's nullptr then we also test the LLVM version number?  For each
major release (3.9, 4.0, 5.0, ... you can see that they did the same
kind of versioning schema change that we did!) there will eventually
be a minor/patch release number where this works even when nullptr is
returned here.

This problem is going to come up on any architecture not covered in
the following code, namely anything but x86, x86_64 and (since 6.0)
aarch64 (aka arm64), so we definitely don't want to leave JIT disabled
once that bug is fixed:

https://github.com/llvm-mirror/llvm/blob/release_39/lib/ExecutionEngine/Orc/IndirectionUtils.cpp#L48
https://github.com/llvm-mirror/llvm/blob/release_60/lib/ExecutionEngine/Orc/IndirectionUtils.cpp#L48

-- 
Thomas Munro
http://www.enterprisedb.com

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".