GATE CS 2008 Q37 — Machine Instructions and Addressing Modes

In high-performance RISC architectures, the register file is organized into multiple register windows to optimize function calls.

To understand the distinction:

• Multiple Register Windows: Having multiple separate windows allows each function to have its own dedicated set of registers, which reduces the need to save and restore registers to/from the stack in memory (Statement II).
• Overlapping of Windows: The overlap between adjacent windows allows the out registers of the caller to directly serve as the in registers of the callee. This specific overlap mechanism eliminates the need to pass function parameters and access local variables via memory (Statement I).

Since the question specifically asks about the effect of the overlap, it directly reduces memory accesses for function locals and parameters. Instruction fetches (Statement III) are unaffected by register windowing.

Therefore, I only is the most precise answer.