[OT?] Unimplemented instructions on a G5?

[Segher Boessenkool]

> 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.

http://www-106.ibm.com/developerworks/eserver/pdfs/archpub1.pdf
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).


Segher


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