[PATCH] arm: Add ARM VFPv4 VFMA instruction support in fma/fmaf (BZ 15503)

[Wilco Dijkstra]

Hi Adhemerval,

>> If an ifunc using native FMA has a 2x slow down vs inline FMA, are we talking about
>> a 10-25x hit with emulated fma()???
>
> I will need to get some real number to give you a better answer, but I recall that
> running x86_64-linux-gnu without multiarch I saw pretty bad results that something
> that 10x indeed.

So I did some quick runs on the new atanh/asinh/acosh on Arm, and it looks FMA
ifunc has ~50% overhead over inlined FMA, and emulated FMA is 15 times slower
than inline FMA (and 10x ifunc FMA).

Cheers,
Wilco