Characteristics of Some CISCs, RISCs, and Superscalar Processors

COMPUTER ORGANIZATION AND ARCHITECTURE DESIGNING FOR PERFORMANCE NINTH EDITION

Although RISC architectures have been defined and designed in a variety of
ways by different groups, the key elements shared by most designs are these:
  •  A  large  number  of  general-purpose  registers,  and/or  the  use  of  compiler
technology to optimize register usage
  •  A limited and simple instruction set
  •  An emphasis on optimizing the instruction pipeline
Table 15.1 compares several RISC and non-RISC systems.
We begin this chapter with a brief survey of some results on instruction sets,
and then examine each of the three topics just listed. This is followed by a descrip-
tion of two of the best-documented RISC designs.