Should there be an edge from 00 to 03?

@weimin. Operation 03 is already dependent on 00 via transitivity through operation 02, so it was not drawn. (It is not possible to run 03 simultaneously with 00 because 02 must come after 02 which much come after 00.)

To make the idea of the benefits of superscalar processors concrete, a superscalar processors able to spawn at least 3 instructions in parallel would be able to complete the execution of this program in 5 clock cycles instead of the 10 it would take a non-superscalar processor.

A superscalar processor "respects program order" if it guarantees the output of any program it runs is identical to the output when the program is run sequentially, even if the processor performs some individual instructions in parallel (e.g., via ILP) or in a rearranged order as an optimization.

For a superscalar processor to "respect program order", it executes instructions of a program in an order that respects instruction dependency. For example, in the dependency graph in this slide, a superscalar processor cannot execute instruction 06 before any of its ancestor (00, 01, 02, 04) is executed.