Re: ABI, I don't get it...

[Andrew Pinski <pinskia@gmail.com>]

On Wed, Aug 24, 2016 at 8:46 AM, Maciej W. Rozycki <macro@imgtec.com> wrote:
> On Sun, 14 Aug 2016, Paul_Koning@Dell.com wrote:
>
>> > with a toolchain that was supposedly 64-bit native, hard-float.  Why
>> > the floating point selection is soft, I cannot say.
>>
>> Perhaps because some other MIPS64 machines don't have float?  The
>> Sibyte series comes to mind.  We use soft-float for that reason, even
>> though XLR and XLP do have it.

Also FYI. Octeon 1/+ and Octeon 2 do not have a FPU while Octeon 3
does have one.
Maybe most people now days are targeting the Octeon family :).

Thanks,
Andrew Pinski


>
>  FYI, the SiByte/Broadcom SB-1 processor cores do have an FPU albeit IIRC
> early (A0?) steppings had fatal errata making the unit less than usable
> (they also had other issues making them usable even less).  This may have
> been the reason you have chosen a software configuration which avoids the
> use of the FPU with these processors.  Later revisions were fine.  I've
> used the FPU with a B2 stepping SB-1 myself with no issues; there was a
> later C0 revision as well.
>
>  Ralf (cc-ed) may remember a bit more about the story here.
>
>  FWIW,
>
>   Maciej