Chapter 3, Problem 10E

Explanation of Solution

Justification:

• Since FORTRAN 77 has lacks on recursion feature, so the call graph for FORTRAN 77 program will be acyclic.
• Call graph is a flow graph, which is used to represent the calling relationships between subroutines.
• If the two subroutines never appear in the same path from the main in the graph, then they share their memory space with their local variables.
• When a complier allocates the local variables statistically, then one can minimize the size of allocation by performing a topological sort of the call graph.
• The frame of subroutine can be called only from the main program is placed at address zero. After this, other subroutine can use frame whose frames have already been assigned locations is placed at the first address.
• The following example shows a simple acyclic call graph flow...