[PATCH] PPC64 Use hardware sqrt.

[Paul Mackerras]

Tom Gall writes:

> Kumar Gala wrote:
> 
> > Understand, but future PPC64 from Freescale (former Motorola SPS) are 
> > unlikely to implement it.
> 
> If they do then likely they will also leave the other optional floating 
> point operations unimplemented and in that case the correct way to build 
> glibc is with the --nf option which is already the case for PPC32 
> processors without floating point.

Hmmm, the basic floating-point instructions aren't optional in the
PowerPC architecture AFAIK, but fsqrt, fsqrts, fres, frsqrte, fsel
(and maybe 1 or 2 others) are.  All the 32-bit "desktop" CPUs from
Motorola (601, 604, 750, 74xx) had floating-point but didn't implement
fsqrt or fsqrts.

Since Kumar works for Freescale, if he says Freescale is likely to
implement 64-bit PowerPC cpus with the basic floating-point
instructions but without fsqrt[s], I'd be inclined to believe him.
(I just hope they don't do 64-bit book E... :)

Maybe we will end up needing another bit in the CPU features word in
the aux vector.

Regards,
Paul.