legacy - a performance monitor patch
legacy patch typo
legacy - run an example to test
simu - working on monitor patch
simu - track on push
simu - monitor - push tests
simu - simplify a little bit
simu - monitor patch - track pop
simu - stat pretty print
legacy - some criticize
simu - patch done
simu - patch test

pretty much the same thing, a little simpler
ex 5.14 - here is the plan
simu - observation: unnecessary merge
simu - relax condition on reg init
simu - simplify reg init
legacy-easy - simplify reg init
simu - modify comment
simu - make machine from ctl-txt and op-builder
simu - impl fix