Re: Deprecate nwfpe emulation?

On Mon, 27 Jan 2025 at 21:02, Richard Henderson
[off-list ref] wrote:

On 1/27/25 09:46, Peter Maydell wrote:

quoted

On Mon, 27 Jan 2025 at 17:27, Philippe Mathieu-Daudé [off-list ref] wrote:

quoted

On 27/1/25 12:27, Peter Maydell wrote:

quoted

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