Do you have an online reference for that?

I tried this IBM one but it has a terrible clickthrough to attempt to avoid GDPR:

https://www.ibm.com/developerworks/library/l-ppc/index.html

And, as seems to pretty much always be the case, the wikibooks looks promising but then appears to be empty:

https://en.wikibooks.org/wiki/PowerPC_Assembly/Instructions

This one seemed pretty good:

https://www.cs.uaf.edu/2011/fall/cs301/lecture/11_21_PowerPC...

If you're looking for a reasonably readable summary, there was a fair amount on Raymond Chen's blog recently. Part one (of about 15 IIRC) here:

https://blogs.msdn.microsoft.com/oldnewthing/20180806-00/?p=...