[Debian-coldfire-devel] Progress?

[Sven Luther]

On Sat, Jun 03, 2006 at 08:17:44AM +1000, Adam Conrad wrote:
> Wouter Verhelst wrote:
> > On Fri, Jun 02, 2006 at 12:42:54PM +0200, Aurélien GÉRÔME wrote:
> >> It also occurs to me that Coldfire has some opcodes legacy m68k
> >> has not.
> > 
> > Yes, but none of those are of great importance, and can be worked
> > around. Apart from the FF1 opcode ("Find First One", an opcode to find
> > the first 1-bit in an operator), they all belong to things such as the
> > MAC/EMAC ((Enhanced) Multiply ACcumulator, for hardware-accelerated
> > vector math) or the crypto accelerator units.
> 
> These should be handled via glibc's hwcap interface (which m68k has no,
> as of yet, put to use, but will certainly be doing in the future), much
> in the same was as i386 has /usr/lib/i686/cmov, /usr/lib/i686,
> /usr/lib/i586, etc.
> 
> It's worth masking off these new options as "spiffy high performance
> hwcap options", because they're just that.  In the other direction,
> however, it's more worth having the kernel emulate older m68k opcodes
> that the ColdFire can't support, since the ColdFire is clearly fast
> enough to pull that off. (We certainly wouldn't want a 68040 trying to
> emulate the new whizbang vector math stuff, though... Eek)

Notice thought that there seems to be some reversation on the glibc side to
accept something like a altivec hwcap thingy on powerpc, some kind of
political issue probably.

Friendly,

Sven Luther