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Unformatted text preview: bubbles as possible. ( Do NOT use any other techniques such as forwarding .) After adding the necessary bubbles, how many clock cycles are required to complete the execution of this piece of code? Solution: (Shorthand: I=IF, D=ID, X=Ex, M=Mem,W=WB) 1 I D X M W 2 I D X M W 3 I D X M W Student Name:________________________________________ 4 I D X M W 5 or 6 I D X M W 6 * I D X M W Note: Instruction 2 cannot start 1 cycle earlier since it would result in a structural hazard (i.e., the M of instruction 1 would overlap with the I of instruction 2). 17 or 18 cycles depending on if the branch is taken. * If the previous instruction is 6 (the branch is taken), then this row is empty....
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- Fall '08
- Central processing unit, Instruction pipeline, WB Mem EX, 0 0 M, 0 0 0 M, 0 0 0 0 0 0 W