Interested parties can also look at how the Tamarin VM implements those bitwise opcodes natively.

http://www.mozilla.org/projects/tamarin/

Flash opcodes into Nanojit IR:

http://hg.mozilla.org/tamarin-central/raw-file/4eb9f961a087/...

Nanojit IR to native x86 translation tables?

http://hg.mozilla.org/tamarin-central/raw-file/4eb9f961a087/...