Re: JIT compiling with LLVM v10.0

From: Pierre Ducroquet <p(dot)psql(at)pinaraf(dot)info>
To: pgsql-hackers(at)lists(dot)postgresql(dot)org
Cc: Andres Freund <andres(at)anarazel(dot)de>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: JIT compiling with LLVM v10.0
Date: 2018-02-07 19:35:12
Message-ID: 3309415.tx5WB8eTnp@peanuts2
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

On Wednesday, February 7, 2018 3:54:05 PM CET Andres Freund wrote:
> Hi,
> I've pushed v10.0. The big (and pretty painful to make) change is that
> now all the LLVM specific code lives in src/backend/jit/llvm, which is
> built as a shared library which is loaded on demand.
> The layout is now as follows:
> src/backend/jit/jit.c:
> Part of JITing always linked into the server. Supports loading the
> LLVM using JIT library.
> src/backend/jit/llvm/
> Infrastructure:
> llvmjit.c:
> General code generation and optimization infrastructure
> llvmjit_error.cpp, llvmjit_wrap.cpp:
> Error / backward compat wrappers
> llvmjit_inline.cpp:
> Cross module inlining support
> Code-Gen:
> llvmjit_expr.c
> Expression compilation
> llvmjit_deform.c
> Deform compilation
> I generally like how this shaped out. There's a good amount of followup
> cleanup needed, but I'd appreciate some early feedback.


I also find it more readable and it looks cleaner, insane guys could be able
to write their own JIT engines for PostgreSQL by patching a single file :)
Since it's now in its own .so file, does it still make as much sense using
mostly the LLVM C API ?
I'll really look in the jit code itself later, right now I've just rebased my
previous patches and did a quick check that everything worked for LLVM4 and
I included a small addition to the gitignore file, I'm surprised you were not
bothered by the various .bc files generated.

Anyway, great work, and I look forward exploring the code :)


Attachment Content-Type Size
0001-Add-support-for-LLVM4-in-llvmjit.c.patch text/x-patch 2.4 KB
0002-Add-LLVM4-support-in-llvmjit_error.cpp.patch text/x-patch 1.4 KB
0003-Add-LLVM4-support-in-llvmjit_inline.cpp.patch text/x-patch 3.1 KB
0004-Don-t-emit-bitcode-depending-on-an-LLVM-5-function.patch text/x-patch 834 bytes
0005-Fix-warning.patch text/x-patch 1.3 KB
0006-Ignore-LLVM-.bc-files.patch text/x-patch 487 bytes
0007-Fix-building-with-LLVM-3.9.patch text/x-patch 2.8 KB
0008-Fix-segfault-with-LLVM-3.9.patch text/x-patch 1.1 KB

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Robert Haas 2018-02-07 20:39:33 Re: postgres_fdw: perform UPDATE/DELETE .. RETURNING on a join directly
Previous Message Stephen Frost 2018-02-07 18:42:54 Re: [HACKERS] Proposal: generic WAL compression