Assume for arithmetic, load$/$store$,$ and branch instructions, a processor has CPIs of $1,12,$ and $5,$

respectively. Also assume that on a single processor a program requires the execution of $2\mathrm{.}56E9$

arithmetic instructions, $1\mathrm{.}28E9$loa$\frac{d}{s}$tore instructions, and $256$million branch instructions.

Assume that each processor has a $2GHz$ clock frequency.

Assume that, as the program is parallelized to run over multiple cores, the number of arithmetic

and load$/$store instructions per processor is divided by $0\mathrm{.}7p($where $p$ is the number of processors$)$

but the number of branch instructions per processor remains the same.

a$.$ Find the total execution time for this program on $1,2,4,$ and $8$ processors, and show the

relative speedup of the $2,4,$ and $8$ processor result relative to the single processor result.

Use the table below for your computations.

b$.$ If the CPI of the arithmetic instructions was doubled, what would the impact be on the

execution time of the program on $1,2,4,$ or $8$ processors?

c$.$ To what should the CPI of load$/$store instructions be reduced for a single processor to match

the performance of four processors using the original CPI values?