[Debian-coldfire-devel] Progress?

[Adam Conrad]

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)

... Adam