Differences in the Ranked and Hierarchical Views

The hierarchical view differs from the ranked view in two important respects.

• Entries in the Name column of the hierarchical view are indented in order to show which functions or routines call which others.
• A %Parent column in the hierarchical view allows you to see what percentage of a parent routine's simulation time is used in which subroutines.

Indentation in the Name column of the Hierarchical Profile window indicates which line is calling a function. For example, in the hierarchical view above, the line store.vhd:43 calls ieee_src/mti_std_logic_unsigned.vhd:429.

The hierarchical view presents data in a call-graph style format that provides more context than does the ranked view about where simulation time is spent . For example, your models may contain several instances of a utility function that compute the maximum of 3-delay values. A ranked view might reveal that the simulation spent 60% of its time in this utility function, but would not tell you which routine or routines were making the most use of it. The hierarchical view will reveal which line is calling the function most frequently. Using this information, you might decide that instead of calling the function every time to compute the maximum of the 3-delays, this spot in your VHDL code can be used to compute it just once. You can then store the maximum delay value in a local variable.

The %Parent column provides the percent of simulation time a given entry used of its parent's total simulation time. From this column, you can calculate the percentage of total simulation time taken up by any function. For example, if a particular parent entry used 10% of the total simulation time, and it called a routine that used 80% of its simulation time, then the percentage of total simulation time spent in that routine would be 80% of 10%, or 8%.

In addition to these differences, the ranked view displays any particular function only once, regardless of where it was used. In the hierarchical view, the function can appear multiple times - each time in the context of where it was used.

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