[LLVMdev] PowerPC JIT available for testing

[Reid Spencer]

The DynamicLibrary.cpp code is written and I believe it to be complete,
but it hasn't been tested much (at all). llvm-ld uses it to load its
plug-in optimization module.   The implementation will use ltdl library
if its available, otherwise it tries to use dlopen/dlsym if they are
available, otherwise you get a compile time warning and (void*)0 if you
try to look up a symbol.

I'm not sure about the libtool implementation but it does more than just
accommodate the platform differences for the interface function names.
It also makes sure that platform requirements for initialization of the
loaded module, etc. are taken into account (e.g. static initialization
of data in the shared object). I don't think we want to re-invent this,
its nasty stuff.  As for whether it solves the lookup of symbols
starting with __, I'm unsure. You'd have to look at the ltdl
implementation.

Reid.

On Sun, 2004-11-28 at 10:38, Chris Lattner wrote:
> On Sun, 28 Nov 2004, Reid Spencer wrote:
> > FYI .. if you want to see how this works, check out
> > lib/System/DynamicLibrary.cpp and platform versions of it.
> 
> Is it an option to use this interface now?  How does libtool implement
> dlsym on darwin if not through the obvious interface?  Can we just use
> whatever it uses?
> 
> -Chris
> 
> > On Sun, 2004-11-28 at 10:03, Reid Spencer wrote:
> > > Well, one of these days we'll be using libltdl (libtool's dynamic
> > > library support) to make the interface to dynamic libraries consistent,
> > > somewhat portable, and to get rid of system specific differences like
> > > this.
> > >
> > > Reid.
> > >
> > > On Sun, 2004-11-28 at 10:00, Chris Lattner wrote:
> > > > Hi everyone,
> > > >
> > > > This is just a note to mention that the PowerPC JIT is now operational and
> > > > begging for testing in mainline CVS.  There is one known problem (below),
> > > > but otherwise it works as well as the static PowerPC backend on the test
> > > > suite.
> > > >
> > > > The known problem is that the JIT seems unable to resolve calls to
> > > > external functions that start with "__", such as __eprintf, __moddi3, etc.
> > > > This appears to be something funny in the darwin implementation of dlsym
> > > > (returning null for symbols that are valid if they start with __).  If
> > > > anyone has any ideas of how to make this work, we would love to hear them.
> > > > :)
> > > >
> > > > -Chris
> > >
> > > ______________________________________________________________________
> > > _______________________________________________
> > > LLVM Developers mailing list
> > > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
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> >
> 
> -Chris
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