TODO

TODO
- check that vector class has corresponding scalar version

Features
- vector
  = shuffle, extract, insert (exercise)
- various data type, i32, i16, i8
- aggregate type
  = multidimensional arrays
  = structure type

Correctness
- how to prevent users from making a mistake on machine description (ins & outs).
  = e.g. putting arg 0 to be output of str# => backward can't find solution.
  = SOLUTION: extract ins & outs from simulator!!!

Increase precision in enum
- synthesize constrants
- in reduced-bitwidth domain: try all 4-bit constants
- e.g. Preston load1

Advance usage
   - define-progstate-stype #:const
   - sort-live
   - combine-live & update-live (GA)
   - (reduce-precesion) in forwardbackward

Profile:
preston/program/ex1 on kaopad
stoch -s: 6, 20, 2, 4*, 1