initial commission

usable version, satisfying basic requirements.

several notes
-- the original source by linus yang is NOT that friendly; i intended
to modify it somehow, but gradually i found i have to make great
changes to make it work, debugging took most of my time
so advice is, DON'T do that. if u do it on your own at very beginning,
u should make it sooner.
-- take care of the pipe-control logic. web asides on hcl-implements at
cs-app2 would be great help
-- small trick but great headache. take care of the minus immediates; u
gotta convert it yourself. that took me HOURs to debug…
-- the rest would be updated soon :)