Native wrapper compilation and LLVM 2.6

[Gary Benson]

Andrew Haley wrote:
> Gary Benson wrote:
> > This past week or so I've been working on making Shark support
> > compilation of native (JNI) method wrappers.  The way HotSpot
> > does this has the wrappers being generated outside the compiler
> > thread, so you have LLVM calls being made from two different
> > threads.
> >
> > LLVM < 2.6 doesn't support this, and it's not possible to work
> > around this with locking; the compiler thread in HotSpot runs
> > _thread_in_native, which means it cannot hold locks.  (And if
> > you hack one in there, it deadlocks at the first safepoint ;))
> >
> > I'm wondering... is anyone using Shark with LLVM < 2.6?  I have
> > two options here:
> >
> >  - Write it such that JNI compilation is conditional on
> >    LLVM >= 2.6.  This requires lots of #ifdefs but is possible.
> >
> >  - Strip out LLVM < 2.6 support.  This is easier (and neater,
> >    IMO).  But not really an option if someone depends on it.
> >
> > What do people think?
>
> Shark is advanced technology: I don't think it would hurt to
> require LLVM >= 2.6.  The only person who might be badly
> affected is Ed Nevill, I suspect.

He should be ok, I don't think ARM works at all without the
latest and greatest.

Cheers,
Gary

-- 
http://gbenson.net/