Register Renaming: Techniques and Architectures

This lecture discusses register renaming, a crucial technique in modern processor design aimed at eliminating write-after-read (WAR) and write-after-write (WAW) hazards. The instructor begins by explaining the importance of register renaming in achieving high instruction throughput and efficient out-of-order execution. The lecture covers various historical implementations of register renaming in different processor architectures, including both RISC and CISC designs. Key concepts such as the scope of renaming, the layout of renamed registers, and the methods of register mapping are explored in detail. The instructor emphasizes the challenges of implementing associative structures in hardware, particularly in relation to instruction scheduling and execution. The lecture also introduces the concept of a mapping table to simplify the tracking of register states and improve performance. By examining the MIPS R10000 architecture, the instructor illustrates how these techniques are applied in practice, highlighting the trade-offs involved in different renaming strategies. Overall, this lecture provides a comprehensive overview of the principles and practices of register renaming in advanced computer architecture.