[llvm-dev] Manipulating global address inside GlobalAddress SDNode in (RISCV) LLVM backend

[Tim Northover via llvm-dev]

On Thu, 11 Jul 2019 at 18:03, Reshabh Sharma <reshabhsh at gmail.com> wrote:
> Ah now I could see it more clearly. I was not sure that should I add them (MO_LO32_LO and MO_LO32_HI), btw this was backup plan. Probably for now we are going with this. I implemented them today and they seem to work well.

By the way, I probably should have said sooner but most targets with
64-bit pointers don't (at least in the default mode) materialize
64-bit absolute pointers as we've been discussing.

x86 requires all global variables live with code in the low 2GB of
memory, which allows direct use of %rip-relative addressing-modes.
AArch64 requires all globals & code to be within 4GB of each other at
an arbitrary location in memory.

If you adopted similar constraints for RISC-V you could probably use
the existing code virtually unchanged.

Cheers.

Tim.