Horton

Re: LLVM 16 (opaque pointers)

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Thomas Munro <thomas.munro@gmail.com>
Cc: Ronan Dunklau <ronan.dunklau@aiven.io>, Devrim Gündüz <devrim@gunduz.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Fabien COELHO <coelho@cri.ensmp.fr>, Dmitry Dolgov <9erthalion6@gmail.com>
Date: 2023-10-20T22:12:13Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. jit: Adjust back-patch of f90b4a84 to 12 and 13.

  2. Log LLVM library version in configure output.

  3. jit: Changes for LLVM 17.

  4. jit: Supply LLVMGlobalGetValueType() for LLVM < 8.

  5. jit: Support opaque pointers in LLVM 16.

  6. jit: Reference function pointer types via llvmjit_types.c.

Hi,

On 2023-10-21 10:48:47 +1300, Thomas Munro wrote:
> On Thu, Oct 19, 2023 at 6:20 AM Thomas Munro <thomas.munro@gmail.com> wrote:
> > Interestingly, a new problem just showed up on the the RHEL9 s390x
> > machine "lora", where a previously reported problem [1] apparently
> > re-appeared.  It complains about incompatible layout, previously
> > blamed on mismatch between clang and LLVM versions.  I can see that
> > its clang is v15 from clues in the conflig log, but I don't know which
> > version of LLVM is being used.  However, I see now that --with-llvm
> > was literally just turned on, so there is no reason to think that this
> > would have worked before or this work is relevant.  Strange though --
> > we must be able to JIT further than that on s390x because we have
> > crash reports in other threads (ie we made it past this and into other
> > more advanced brokenness).
> 
> I see that Mark has also just enabled --with-llvm on some POWER Linux
> animals, and they have failed in various ways.  The failures are
> strangely lacking in detail.  It seems we didn't have coverage before,
> and I recall that there were definitely versions of LLVM that *didn't*
> work for our usage in the past, which I'll need to dredge out of the
> archives.  I will try to get onto a cfarm POWER machine and see if I
> can reproduce that, before and after these commits, and whose bug is
> it etc.

I'm quite sure that jiting did pass on ppc64 at some point.


> I doubt I can get anywhere near an s390x though, and we definitely had
> pre-existing problems on that arch.

IMO an LLVM bug, rather than a postgres bug, but I guess it's all a matter of
perspective.
https://github.com/llvm/llvm-project/issues/53009#issuecomment-1042748553

I had made another bug report about this issue at some point, but I can't
refind it right now.

Greetings,

Andres Freund