This version is intended for compiler hackers. We are in the midst of substantial structural changes, and this is a snapshot. Target machine instructions can be marked with client specific annotations. There is a new way to describing memory aliasing.
Execution time improves.
There is a larger set of operators. Also, some of the operation names have been changed. Both e1 and e2 can be evaluated eagerly. Where order of evaluation is important, it should be made explicit by sequentially assigning values to temporary registers. The encoding of physical registers has been changed.