[LLVMdev] Address arithmetic result is incorrectly zero-extended (X86)

[Tim Northover]

> I tried to
> add an extra check that makes the function return false if the offset of the
> GlobalAddressSDNode is negative, but this causes the instruction selector to
> not select an instruction at all (it fails with a "Cannot select" error).

That's presumably because the function that gets called for the
instruction you *do* want to emit isn't expecting to have to deal with
offset globals and returns false. Your best option is probably to find
it and add the functionality.

It looks like you're most of the way there, having found and modified
the 32-bit function.

Cheers.

Tim.