Re: JIT compiling with LLVM v9.0

Andres Freund <andres@anarazel.de>

From: Andres Freund <andres@anarazel.de>
To: Jeff Davis <pgsql@j-davis.com>
Cc: Pierre Ducroquet <p.psql@pinaraf.info>, pgsql-hackers@lists.postgresql.org
Date: 2018-01-25T06:38:16Z
Lists: pgsql-hackers
Hi,

On 2018-01-24 22:33:30 -0800, Jeff Davis wrote:
> On Wed, Jan 24, 2018 at 1:35 PM, Pierre Ducroquet <p.psql@pinaraf.info> wrote:
> > In LLVM 5.0, it looks like DebugInfo.h is not available in llvm-c, only as a C
> > ++ API in llvm/IR/DebugInfo.h.
> 
> The LLVM APIs don't seem to be very stable; won't there just be a
> continuous stream of similar issues?

There'll be some of that yes. But the entire difference between 5 and
what will be 6 was not including one header, and not calling one unneded
function. That doesn't seem like a crazy amount of adaption that needs
to be done.  From a quick look about porting to 4, it'll be a bit, but
not much more effort.

The reason I'm using the C-API where possible is that it's largely
forward compatible (i.e. new features added, but seldomly things are
removed). The C++ code changes a bit more, but it's not that much code
we're interfacing with either.

I think we'll have to make do with a number of ifdefs - I don't really
see an alternative. Unless you've a better idea?


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".