GPRPair issue on LLVMLinux side

[Tim Northover]

Hi Tinti,

> Unfortunately I was not able to get the root cause of the error and it is
> being quite difficult to find it. Specially because Linux kernel code is
> huge. Besides it uses a lot of low-level optimizations that probably will
> not appear in any other code base.

That is unfortunate, and I think it has to be the first problem we
solve. At the moment we have no idea where to look, and I'd even be
unsurprised if it turned out the kernel was relying on GCC behaviour
incorrectly.

> Hence I would like to ask for help or rather that patch be reviewed because
> it may have issues. Do you have any other suggestions? If is there any data
> that I could provide please ask me.

Versatile boards aren't exactly commodity items, but I believe it's
what qemu claims to emulate for ARM; do you know if the problem (and
solution) is reproducible under qemu?

Other than that, quick-and-dirty instructions for building a working
Linux kernel with Clang might encourage people to take a look. I've no
idea what should be in .config or how to override Linux's choice of
compiler, for example. And only a vague recollection of how to build a
non-native kernel at all.

Cheers.

Tim.