Deprecate nwfpe emulation?

[Peter Maydell]

On Mon, 27 Jan 2025 at 21:02, Richard Henderson
<richard.henderson at linaro.org> wrote:
>
> On 1/27/25 09:46, Peter Maydell wrote:
> > On Mon, 27 Jan 2025 at 17:27, Philippe Mathieu-Daudé <philmd at linaro.org> wrote:
> >> On 27/1/25 12:27, Peter Maydell wrote:
> >>> We have one test case in check-tcg which purports to be checking
> >>> iwMMXt. In fact it is doing no such thing: it runs the test without
> >>> selecting an iwMMXt CPU, which means the iwMMXt insns are interpreted
> >>> as FPA11 insns by the linux-user emulate_arm_fpa11() code. So the test
> >>> prints garbage and then succeeds anyway.
> >>
> >> Uh...
> >
> > It had me confused for a while, because I'd convinced myself
> > by code inspection that we only enabled iwMMXt if you
> > manually asked for a pxa2xx CPU and not in the default 'max'
> > CPU, and then I found this test case that we were running
> > with the default CPU type and which was apparently passing :-)
>
> Any chance we can deprecate the fpa11 stuff too?

I had wondered about that from the QEMU side, but it's
a little trickier than the iwmmxt deprecation because
we enable the fpa11 emulation by default, so it's harder
to tell if any users are still using it. (In practice I'm
pretty sure it'll only being used if people are running
old binaries that used the ancient "floating point return
values go in an FPA register" ABI.)

-- PMM