Question

If a circular register buffer is used to handle local variables for nested procedures, describe two approaches for handling global variables.

Answer 1

The two approaches for handling global variables where a circular register buffer is used to handle local variables for nested procedures:

1. Variables declared as global in an HLL can be assigned memory locations by the compiler, and all machine instructions that reference these variables will use memory-reference operands.
2. Incorporate a set of global registers in the processor. These registers would be fixed in number and available to all procedures.