llvm dev - Oct 2011 - [LLVMdev] Typo in IsLegalToCallImmediateAddr?

Rafael,

Use this bitcode:

define i32 @main() nounwind {
entry:
  %call = tail call i32 inttoptr (i64 256 to i32 ()*)() nounwind
  ret i32 0
}

And this command:

$ llc -mtriple "i686-linux-gnu" test.ll -o test.s -filetype=asm
-relocation-model=pic

- pdox

> And this command:
> 
> $ llc -mtriple "i686-linux-gnu" test.ll -o test.s -filetype=asm
> -relocation-model=pic
I can reproduce it now. Sorry, I was using a test returning void and we
don't have tail call of immediate.

My impression in that the right fix would be to just remove the
"isTargetELF()". It would make the function correct for ELF and not
less
correct for other formats, since it is already broken for a format with
no calls to immediate.
> - pdox
Cheers,
Rafael

Rafael,

I believe MachO can't represent this relocation, even in non-PIC mode.
On my Mac, I tried compiling "call 256". I got:

in section __TEXT,__text reloc 0: R_ABS reloc but no absolute symbol
at target address

I believe the correct thing to do is:

isTargetELF() && TM.getRelocationModel() == Reloc::Static

This will do the right thing on ELF, and the right thing on other
formats. This may have been the original intent.

- pdox