Consider the following code fragment being run on a 32-bit 5-stage DLX pipeline LW SR2, 100(SR5) SWSR2, 200(SR6) (3+ 3 +2-8 points) (a) Without any bypass paths, how many cycles does the SW instruction need to stall for? ANSWER: Number of stall cycles (b) Design a bypass path that reduces the number of stall cycles by the maximum extent possible What is the beginning and end of this bypass path in terms of begin/end of which pipeline stages? What is the new (reduced) number of stall cycles with this bypass path? Beginning of bypass-(begin/end) End of bypass(begin/end) New (reduced) # of stall cycles- stage stage of of cycles. ANSWER: (c) For the bypass path in part (b), there is multiplexer (MUX) needed at its end when it feeds back a value into the pipeline. Considering each 32-bit value as one input, how many inputs does this MUX choose between and what are they? Describe the inputs in words; a figure is not necessary Describe the condition used to select between the MUX inputs. Assume no other bypass paths are present. Consider the following code fragment being run on a 32-bit 5-stage DLX pipeline LW SR2, 100(SR5) SWSR2, 200(SR6) (3+ 3 +2-8 points) (a) Without any bypass paths, how many cycles does the SW instruction need to stall for? ANSWER: Number of stall cycles (b) Design a bypass path that reduces the number of stall cycles by the maximum extent possible What is the beginning and end of this bypass path in terms of begin/end of which pipeline stages? What is the new (reduced) number of stall cycles with this bypass path? Beginning of bypass-(begin/end) End of bypass(begin/end) New (reduced) # of stall cycles- stage stage of of cycles. ANSWER: (c) For the bypass path in part (b), there is multiplexer (MUX) needed at its end when it feeds back a value into the pipeline. Considering each 32-bit value as one input, how many inputs does this MUX choose between and what are they? Describe the inputs in words; a figure is not necessary Describe the condition used to select between the MUX inputs. Assume no other bypass paths are present