Consider the following program:

program pipeline$9$

R$=4$

S$=10$

T$=5$

U$=20$

S$=$S$+$R

T$=$T$+$R

R$=$R$/3$

R$=$T

end

Compile the code and load it in CPU$-$OS simulator. Perform the following:

Execute the above program using non$-$pipelined processor and pipelined processor and answer the following questions.

Note: Every time flush the pipeline before running the code

A$)$ Non$-$pipelined Processor:

To enable non$-$pipelined processor, check $$No instruction pipeline$$ check box in control panel.

a$)$ How many stages are there in non$-$pipelined processor? List them.

Solution:

b$)$ Fill in the following after executing of above program using non$-$pipelined processor.

Clocks Instruction Count CPI Speed up Factor

Non$-$Pipelined Processor

c$)$ What are the contents of General$-$purpose registers after the execution of the program?

Solution:

B$)$ Pipelined processor:

To use, enable pipelined processor, uncheck $$No instruction pipeline$$ check box in control panel.

a$)$ Fill in the following table with respect to pipelined processor execution of the above program:

Pipelined processor conditions Clocks Instruction Count CPI Speed up Factor Data hazard

$($Yes$/$No$)$ Contents of registers used by the program

Check $$Do not insert bubbles$$ check box

Uncheck $$Do not insert bubbles$$

b$)$ Write your observation on the impact of bubble insertion. Is there a way to improve the CPI and Speed up factor? If so give the solution.

Solution: