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Re: ABI, I don't get it...
> On Aug 24, 2016, at 11:46 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.
>
> 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.
It's been a while, but yes, that sounds familiar. Part of the consideration was that we switched to soft-float for that reason, and it worked well enough for what we do that it wasn't interesting to switch back.
paul