> you'd have to reinvent the world to do them

It reminds me of how MIPS branching is wasted on nops:

https://electronics.stackexchange.com/questions/28444/mips-p...

"The trick in writing efficient code is to put in an instruction that will be useful as part of the loop that is being taken executed, but do no harm if the branch is not taken.

The MIPS designers were counting on compiler writers to write clever enough code generators to handle this efficiently. However many do not (including Microchips C32 compiler, based on GCC), and just put NOP's after every branch, wasting both code space and cycles"