1. Given the following sequential list of VEX operations: (Note that by “VEX ope
ID: 3744940 • Letter: 1
Question
1. Given the following sequential list of VEX operations: (Note that by “VEX operations”, we are specifying VEX syntax, but not that we are using the VEX architecture.)
A. add $r4 = $r2, $r3
B. sub $r2 = $r1, $r5
C. mpy $r4 = $r5, $r2
D. add $7 $r7 = $r2, $r4
E. mpy $r8 = $r5, $r4
F. sub $r8 = $r1, $r4
I. Can operations A and B be scheduled in the same cycle? Explain why.
II. Can operations B and C be scheduled in the same cycle? Explain why.
III. Can operation E be scheduled ahead of Operation D? Explain why. If it cannot, explain what technique could be used that would allow operation E to be scheduled ahead of operation D?
IV. Can operation F be scheduled ahead of operation E? Explain why. If it cannot, explain what technique could be used that would allow operation F to be scheduled ahead of
operation E?
Explanation / Answer
Answer is as follows :
I. Can operations A and B be scheduled in the same cycle? Explain why.
Ans : No, A and B are can't scheduled in the same cycle becasue there is data dependecy of type WAR i.e. Write after Read on register $r2 that may cause improper result. So they are not possible in single cycles.
II. Can operations B and C be scheduled in the same cycle? Explain why.
Ans : No, B and C are can't scheduled in the same cycle becasue there is data dependecy of type RAW i.e. Read after Write on register $r2 that may cause improper result. So they are not possible in single cycles.
III. Can operation E be scheduled ahead of Operation D? Explain why. If it cannot, explain what technique could be used that would allow operation E to be scheduled ahead of operation D
Ans : Yes, operation E be schedule ahead of operation D. Due to effect of operatoin C, the operation D can't update the proper value of register $r4 which is used in operation E. So E is execute after D.
IV. Can operation F be scheduled ahead of operation E? Explain why. If it cannot, explain what technique could be used that would allow operation F to be scheduled ahead of
operation E?
Ans : Yes operation F be scheduled ahead of operation E beacause of dependency WAW i.e. Write after Write on register $r8.
if there is any query please ask in comments....
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.