Addendum:

>> what is the impact of the missing Altivec instructions
>> (in particular in regard to MorphOS).

> That question is best answered by a MorphOS Team member.

...who now did on another site:

http://www.amiga.org/forums/showpost.php?p=610058

...and another one on yet another site:

http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=33358&forum=28&start=40#605540

[ Edited by Andreas_Wolf on 2011/3/15 16:58 ]