Re: JIT compiling with LLVM v12.2

Hi,

On 2018-03-22 11:36:47 +1300, Thomas Munro wrote:
> On Thu, Mar 22, 2018 at 10:59 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> > On 2018-03-22 10:50:52 +1300, Thomas Munro wrote:
> >> Hmm. There is no LLVM 6 in backports.
> >
> > I think there now is:
> > https://packages.debian.org/search?keywords=llvm&searchon=names&section=all&suite=stretch-backports
> >
> > Package llvm-6.0-dev
> >
> > stretch-backports (devel): Modular compiler and toolchain technologies, libraries and headers
> > 1:6.0-1~bpo9+1: amd64
> >
> > It's a recent addition:
> >
> > llvm-toolchain-6.0 (1:6.0-1~bpo9+1) stretch-backports; urgency=medium
> >
> > * Team upload
> > * Rebuild for stretch-backports.
> >
> > -- Anton Gladky <gladk(at)debian(dot)org> Mon, 12 Mar 2018 18:58:43 +0100
>
> Huh, it hasn't made it to my mirror yet.

Interesting.

> Anyway, I upgraded and built with LLVM 6 and make check now passes on
> my arm64 system. Woohoo!

Yay, thanks for testing!

> Via an off-list exchange I learned that Andres suspects a bug in LLVM
> 3.9 on arm64 and will investigate/maybe file a bug report with LLVM.
> 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.

Greetings,

Andres Freund