Switch to hard-float by default?

[Warner Losh]

On Wed, Jan 10, 2018 at 12:54 PM, John Baldwin <jhb at freebsd.org> wrote:

> I have been working on LLVM libunwind patches for MIPS and the last round
> has
> been to teach the unwinder to handle hard-float.  As part of this I just
> fixed
> a bug which had broken HF support for N32 (in review now), and I have a
> working 'mipsn32hf' world that boots under qemu.  However, if I add
> 'mipsn32hf' to the list of known targets that is yet another world to add
> to make universe.  I wonder if instead we should consider switching MIPS to
> assume hard-float by default?  We made that change for 32-bit arm recently.
>
> The simplest approach would be to add 'mipsn32hf' and then remove all the
> non '*hf' targets from Makefile.inc1 (if we only wanted to support HF).  A
> more drastic approach would be to change the existing 'mips*' targets to
> assume hard-float, remove all the '*hf' targets (which are only in 12
> anyway
> I think?) and add in explicit '*sf' targets if anyone has a need for them.
> Given that none of the *hf targets have been MFC'd are only present in 12
> anyway, maybe the more drastic route is actually better?  If we do go that
> route, does anyone have a use case for a '*sf' target?  That is, is anyone
> running FreeBSD/mips on a processor that does not include an FPA?
>

I think that I retired the last set of SoCs that only had soft float.

I think this is a good idea.

The only use case I can think of is if I'm wrong and some of the early
Atheros SoCs can do soft float. But then we'd just have one supported
soft-float platform to worry about rather than the full generality we have
now.

Warner