Compiler writers often face a choice between implementing a simple, non-optimizing transformation pass that generates poor code which will require subsequent optimization, and implementing a complex, optimizing transformation pass that avoids generating poor code in the first place. A two-pass strategy is compelling because it is simpler to implement correctly, but its disadvantage is that the intermediate data structures can be large and traversing them unnecessarily can be costly.

An action thriller centered on a soldier who wakes up in the body of an unknown man and discovers he's part of a mission to find the bomber of a Chicago commuter train.