Re: JIT compiling with LLVM v9.0

From: Andres Freund <andres(at)anarazel(dot)de>
To: Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com>
Cc: Robert Haas <robertmhaas(at)gmail(dot)com>, Jeff Davis <pgsql(at)j-davis(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: JIT compiling with LLVM v9.0
Date: 2018-01-31 02:05:33
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

On 2018-01-31 14:42:26 +1300, Thomas Munro wrote:
> I'm just starting to look at this (amazing) work, and I don't have a
> strong opinion yet. But certainly, making it easy for packagers to
> put the -jit stuff into a separate package for the reasons already
> given sounds sensible to me. Some systems package LLVM as one
> gigantic package that'll get you 1GB of compiler/debugger/other stuff
> and perhaps violate local rules by installing a compiler when you
> really just wanted libLLVM{whatever}.so. I guess it should be made
> very clear to users (explain plans, maybe startup message, ...?)

I'm not quite sure I understand. You mean have it display whether
available? I think my plan is to "just" set jit_expressions=on (or
whatever we're going to name it) fail if the prerequisites aren't
available. I personally don't think this should be enabled by default,
definitely not in the first release.

> $ c++ -v
> FreeBSD clang version 4.0.0 (tags/RELEASE_400/final 297347) (based on
> LLVM 4.0.0)
> This seems to be a valid complaint. I don't think you should be
> (indirectly) wrapping Types.h in extern "C". At a guess, your
> llvmjit.h should be doing its own #ifdef __cplusplus'd linkage
> specifiers, so you can use it from C or C++, but making sure that you
> don't #include LLVM's headers from a bizarro context where __cplusplus
> is defined but the linkage is unexpectedly already "C"?

Hm, this seems like a bit of pointless nitpickery by the compiler to me,
but I guess...


Andres Freund

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Etsuro Fujita 2018-01-31 02:17:01 Re: [HACKERS] postgres_fdw bug in 9.6
Previous Message Masahiko Sawada 2018-01-31 01:43:28 Re: [HACKERS] GUC for cleanup indexes threshold.