Assume that to spell check a large file, $820,000,000$ instructions are needed. The instructions in

the program are broken down into $4$ different classes, and each class requires $N$ clock cycles to

execute. Specific information is given in the table below. $($Here$,$ N is the same as in the RISC$-$V

multi$-$cycle datapath discussed in class.$)$

$($i$)$ If the total execution time for this program is found to be $1\mathrm{.}57$ seconds, what is the clock cycle

time of the computer on which it was run?

$($ii$)$ Assume that as part of the $820,000,000-$instruction spell check, $25\%$ of all load instructions are

immediately followed by an ALU $/$ R$-$type instruction that uses the data that was just loaded. To

speed up this program, we are contemplating adding a new type of instruction $-$ an ALU instruction

where one of the source operands is a value from memory.

This new instruction will replace the previous, $2$ instruction sequence.

It will take $7$ clock cycles.

Will this change offer any speedup over the original design? If so$,$ how much?

You may assume that the clock rate does not change and your answer to this question does not

depend on your answer to $($i$)$

$($iii$)$ Qualitatively, if you see a speedup, where does it come from? If you do not, why not?