On Tue, 1 Sep 2020, Jakub Jelinek wrote:
> On Tue, Sep 01, 2020 at 01:52:21PM +0200, Richard Biener wrote:
> > OK, I'll see to do that (or fixup the RTL expansion side somehow).
> >
> > Note that clang and gcc disagree about the return value ABI for
> >
> > typedef double v1df __attribute__((vector_size(8)));
> >
> > v1df foo (v1df x)
> > {
> > return x;
> > }
> >
> > where clang returns in %xmm0 while we return by invisible reference.
> > The argument is passed the same (via stack). IIRC we've long said
> > the backends should look at the types, not the modes when deciding
> > how to pass / return things ...
>
> But many of the backends still do use modes.
> If there is an ABI issue, I think we need to find out what the psABI says
> and if it is unclear, discuss with psABI authors.
I've filed PR96895 for this.
Richard.
