> - Sequences of '-','>','<' and '+' are contracted into single instructions. E.g. "----" is replaced with a single SUB(4).
- Mutually cancelling instructions are reduced. E.g. "+++-->><" is equivalent to "+>" and is compiled accordingly.
- Some common constructs are identified and replaced with single instructions. E.g. "[-]" is compiled into a single SET(0).
- Loops known to never be entered are removed. This is the case for loops opened at the very beginning of a program (when all cells are 0) and loops opened immediately after the closing of another loop.