[OT?] Unimplemented instructions on a G5?

Segher Boessenkool segher at kernel.crashing.org
Sat Apr 3 01:32:17 EST 2004

> The offending instruction is the seemingly harmless:
>  mcrxr crX
>   (Move to condition register from XER).
> Does anyone have any idea if IBM left this instruction
> unimplemented. Searching the docs I've found nothing.

Well, the newest PowerPC architecture docs say that it is
an optional insn, i.e., not all cpus might implement it.

I can't say whether the 970 implements it or not.

Chapter 6.

> If it is unimplemented any idea of how hard it will be to
> trap and emulate it?

In Linux?

Last time I did this, it was easy.  Can't seem to find the
patch right now, though.

Emulating will be slow, of course (but I think you know that).


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