Emulating variable bit-shift using only constant shifts?

Question

I\'m trying to find a way to perform an indirect shift-left/right operation without actually using the variable shift op or any branches.

The particular PowerPC pro

Answer 1

There is some good stuff here regarding bit manipulation black magic: Advanced bit manipulation fu (Christer Ericson's blog)

Don't know if any of it's directly applicable, but if there is a way, likely there are some hints to that way in there somewhere.