On Tue, Apr 28, 2020 at 04:23:24PM +0200, Andreas Krebbel wrote:
> Our ABI doesn't specify anything regarding C++ so there is nothing in there
> which really conflicts
> with that. I assume these things will be part of a cross-platform C++ ABI
> instead? I don't see a way
> to add this to our platform ABI without introducing C++ in general there.
>
> Since "no_unique_address" is a new feature we want to pick whatever is most
> efficient and matches
> what other archs do. Passing F, G, J, K in FPRs looks reasonable to me.
Ok, will tweak the patch then once the powerpc+generic one is finalized.
> Given that this is something which hasn't been covered by the ABI so far I'm
> not sure we really need
> a -Wpsabi warning for that.
But [[no_unique_address]] has been introduced already in GCC 9, so e.g. in
the powerpc64le patch I want to warn users about the ABI incompatibility
when padding those.
Your call though.
> Btw. is the no_unique_address flag visible also in Dwarf? Probably it is
> enough for GDB to just
> observe the effect of it to decide how to pass arguments?!
Dunno.
Jakub
