Re: [PATCH] ARM: do not assemble iwmmxt.S with LLVM toolchain

[Andrew Lunn]

On Mon, Apr 13, 2020 at 12:20:57PM -0700, Nick Desaulniers wrote:
> On Fri, Apr 10, 2020 at 2:56 AM Arnd Bergmann <arnd@xxxxxxxx> wrote:
> >
> > On Fri, Apr 10, 2020 at 1:28 AM Jian Cai <caij2003@xxxxxxxxx> wrote:
> > >
> > > iwmmxt.S contains XScale instructions LLVM ARM backend does not support.
> > > Skip this file if LLVM integrated assemmbler or LLD is used to build ARM
> > > kernel.
> > >
> > > Signed-off-by: Jian Cai <caij2003@xxxxxxxxx>
> >
> > It clearly makes sense to limit the Kconfig option to compilers that
> > can actually build it.
> > A few questions though:
> >
> > - Given that Armada XP with its PJ4B was still marketed until fairly
> > recently[1],
> >   wouldn't it make sense to still add support for it? Is it a lot of work?
> 
> Sorry, can you help me verify from that link that PJ4B uses XSCALE?

I think you missed my email. iwmmxt is not Xscale. iwmmxt is an
instruction set of its own, which any ARM processor could implement.

> I
> didn't see references to either in the link provided.  Also, given the
> history of XSCALE as noted by Russell, I'm surprised to see Marvell in
> the mix.

https://en.wikipedia.org/wiki/XScale

	XScale comprises several distinct families: IXP, IXC, IOP, PXA
	and CE.

	Intel sold the PXA family to Marvell Technology Group
	in June 2006.[1] Marvell then extended the brand to include
	processors with other microarchitectures, like ARM's Cortex.

	Andrew