3.(15 pts) Briefly answer the following questions a. (1pts) What is CPI? What does it mean if we have high CPI (assuming others are the same), i.e. better or worse performance? b. (2pts) Why ADDI/SUBI are encoded using I-format instead of R-format? i.e. what is the benefit? C. (2pts) You are invehting your own ISA. You decide all instructions should have the same length and encoding format. Assume that all your instructions use R-type encoding format. How many different instructions of your ISA can have at most? d. (2pts) One of the design principles says "good design demands compromise". What is the compromise here referred to? 3.(15 pts) Briefly answer the following questions a. (1pts) What is CPI? What does it mean if we have high CPI (assuming others are the same), i.e. better or worse performance? b. (2pts) Why ADDI/SUBI are encoded using I-format instead of R-format? i.e. what is the benefit? C. (2pts) You are invehting your own ISA. You decide all instructions should have the same length and encoding format. Assume that all your instructions use R-type encoding format. How many different instructions of your ISA can have at most? d. (2pts) One of the design principles says "good design demands compromise". What is the compromise here referred to