Correct Return Example i demo -retb 0x026 ret LFIDIEMIW bubble FDE MW FDEMW bubble F E M W 0x00b irmo1S5,号esi# Return F E M W Fiqure 4.61 P344 ■ As ret passes through pipeline, stall at fetch stage valM =OxO e While in decode execute, and memory stage fetch the same instruction after ret 3 times Inject bubble into decode vaC←5 stage rB←告esi a Release stall when reach write-back stage Processor– 12 – Processor 0x026: ret F D E M bubble F D E M W W bubble F D E M W bubble F D E M W 0x00b: irmovl $5,%esi # Return F D E M W # demo-retb F D E M W F valC 5 rB %esi F valC 5 rB %esi W valM = 0x0b • • • Correct Return Example ◼ As ret passes through pipeline, stall at fetch stage ⚫ While in decode, execute, and memory stage ⚫ fetch the same instruction after ret 3 times. ◼ Inject bubble into decode stage ◼ Release stall when reach write-back stage Figure 4.61 P344