[LLVMdev] cross-section differences in MC generation

[Rafael Avila de Espindola]

Sent from my iPhone

> On Jun 26, 2014, at 12:33, Justin Hibbits <jrh29 at alumni.cwru.edu> wrote:
> 
> I'm working on Position-independent code for 32-bit PowerPC, but
> running into a problem.  At the beginning of each function, there's a
> pre-word that's the difference between the PICBase (.L1$pb) and the
> GOT.  This works fine when generating assembly output, but it fails
> when generating ELF output, with the error "Cannot represent a
> difference across sections" (line 847, lib/MC/ELFObjectWriter.cpp).
> 
> Roman Divacky suggested I try something with 'let EncoderMethod = ...'
> similar to how the TOC entries are done for ppc64.  However, I'm not
> sure if that would work, given that the TOC on ppc64 is handled
> differently from the GOT on ppc32, and I'm not sure how to represent
> that if it could work.
> 
> Any ideas on how a cross-section diff and relocation could be
> represented for this?
> 


Can you post the generated assembly that works with gas but fails with llvm-mc?

> Thanks,
> Justin
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev