[LLVMdev] DragonEgg3.3 support for gcc cross compilers

Tue Oct 28 11:11:32 PDT 2014

No. The gcc cross compiler being used (tilera-gcc) is indeed 64-bit.

Thanks

On Tue, Oct 28, 2014 at 11:01 AM, Anton Korobeynikov <
anton at korobeynikov.info> wrote:

> Looks like your gcc is 32-bit and you're trying to load 64-bit plugin.
>
> On Tue, Oct 28, 2014 at 8:27 PM, Ajay Panyala <ajay.panyala at gmail.com>
> wrote:
> > Hi Brian,
> >
> > Thanks for sharing your experience with dragonegg.
> > I would like to use tilera-gcc as the compiler driver. native gcc would
> not
> > be able to
> > handle things like tilera specific intrinsics in the source code.
> >
> > I built dragonegg using
> >
> > GCC=/path/to/tilera-gcc48/bin/tile-gcc
> > LLVM_CONFIG=/path/to/tilera-llvm/bin/tilegx-llvm-config make
> >
> > and also tried only emitting the IR
> >
> >    /path/to/tilera-gcc48/bin/tile-gcc -fplugin=/path/to/dragonegg.so
> > -fplugin-arg-dragonegg-emit-ir -S -o hello.ll hello.c
> >
> > (and still get the error: cannot load plugin dragonegg.so: wrong ELF
> class:
> > ELFCLASS64 )
> >
> > - Ajay
> >
> > On Mon, Oct 27, 2014 at 9:39 PM, Brian Faull <bfaull at cog-e.com> wrote:
> >>
> >> Hello,
> >>
> >> There may be plenty more experienced experts on DragonEgg (and hopefully
> >> they'll correct me if I'm wrong), but I figured I'd chime in with my
> brief
> >> experience to start. I have messed with this a bit, and DragonEgg has
> worked
> >> for my experiments.  Your configuration has many things that are
> different
> >> than mine; however, I think you might simply have the cross-compilers
> >> crossed backward; I think you want to use your native gcc as
> >> compiler-driver; pass dragonegg.so to your native-gcc rather than
> >> tilera-gcc. I think you may simply need to do the following:
> >>
> >> 1- Build DragonEgg using your system compiler (or gcc 4.6.4 as
> recommended
> >> on dragonegg.llvm.org); when doing `make`, point explicitly at your
> *build*
> >> (x86_64) GCC of choice, and against your *target* (tilera)
> `llvm-config`.
> >> 2- use your x86_64 compiler-driver as front-end, which due to the magic
> of
> >> DragonEgg and llvm-config will use your target LLVM backend.
> >>
> >> Or it could be really late and I'm not thinking straight. :)
> >>
> >> More detail:
> >> I had to set a few non-obvious (to me) things in the build and use
> >> process, so I'll reflect them here for you and/or posterity.  You will
> need
> >> all three components though: LLVM backend for your architecture (tilera)
> >> I'd suggest a few things to try, in order for you to find a
> configuration
> >> that works for you:
> >>
> >> * Sounds like you're on x86_64 / AMD64.  I'd suggest to start with
> >> building the simplest configuration: using your system compiler to build
> >> everything for your system native architecture, and this will be the
> easiest
> >> configuration to debug.
> >>
> >> * According to the dragonegg.llvm.org web site, DragonEgg works best
> with
> >> GCC 4.6.  You may wish to try that (I recommend looking at
> >> http://gcc.gnu.org/gcc-4.6/ for GCC 4.6.4, which is the latest release
> of
> >> that version).  I don't know exactly why this version is said to work
> best;
> >> perhaps the DragonEgg site is simply stale.  I bootstrapped a clean,
> native
> >> version of 4.6.4 without much headache.
> >>
> >> * Since I wanted to get DragonEgg built to work with GCC4.6.4, I built
> >> DragonEgg with GCC4.6.4.  IIRC, the DragonEgg makefile wants you to
> specify
> >> the compiler as GCC=... rather than CC=... but it looks like it should
> eat
> >> both.  Also, I read somewhere that LLVM3.3's llvm-config had some
> behavior
> >> that argues with DragonEgg.  Contrary to best practice "build outside
> the
> >> source tree" so as to prevent polluting of the source tree, I saw a
> >> recommendation to build *within* the source tree, so I rolled back and
> built
> >> LLVM3.3 *in the source tree* (GASP!) for native (x86_64). In sum, to
> build
> >> DragonEgg I used something like
> >>    GCC=/path/to/gcc464/bin/gcc
> >> LLVM_CONFIG=/path/to/llvm-3.3.src-x86_64/prefix/bin/llvm-config make
> >>
> >> * Then to use this shiny new .so, I started by going only up to the
> point
> >> of emitting LLVM IR so as not to confuse the situation with further
> >> architecture-specific compilation/assembly:
> >>    /path/to/gcc464/bin/gcc -fplugin=/path/to/dragonegg.so
> >> -fplugin-arg-dragonegg-emit-ir -S -o hello.ll hello.c
> >> I also chose to specify the full path of dragonegg.so, so I didn't have
> to
> >> be concerned with library paths.
> >>
> >> Then you should be able to manually use your backend (llvm33/bin/llc,
> >> assembler, etc.) to generate an architecture-specific object.  Once
> you've
> >> got all those components, you should be able to get everything
> integrated
> >> with just one gcc compiler-driver invocation.
> >>
> >> HTH,
> >> Brian
> >>
> >>
> >>
> >>
> >> On Oct 27, 2014, at 11:53 PM, Ajay Panyala <ajay.panyala at gmail.com>
> wrote:
> >>
> >> I am using a gcc (v 4.8.2) cross compiler for the tilera architecture.
> >> There is an LLVM (v 3.3) cross compiler available for tilera
> >> (http://tilera.github.io/llvm),
> >> but the frontend only has partial support for certain tilera intrinsics
> >> and no OpenMP support.
> >>
> >> Hence, I have decided to use DragonEgg (v 3.3) to resolve this. I was
> able
> >> to build
> >> DragonEgg, but when I pass the command line argument
> -fplugin=dragonegg.so
> >> when compiling with the tilera-gcc I get the error
> >>
> >> cannot load dragonegg.so: wrong ELF class: ELFCLASS64
> >>
> >> i.e. the tilera-gcc does not accept the x86 shared library object
> >> dragonegg.so
> >>
> >> The dragonegg sources were built using the x86 GCC, but the plugin
> >> was built to load into the tilera gcc.
> >>
> >> Could someone please point out what I am missing here.
> >>
> >> Thanks
> >> Ajay
> >> _______________________________________________
> >> LLVM Developers mailing list
> >> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >>
> >>
> >
> >
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> >
>
>
>
> --
> With best regards, Anton Korobeynikov
> Faculty of Mathematics and Mechanics, Saint Petersburg State University
>
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