5/21/2023 0 Comments Define wasted![]() (You may also neglect the time requried to refill the pipeline during branches and at the start of program execution) What is the average number of instructions that can be executed each second with the same clock in this case. Now suppose that the CPU is pipelined, so that each instruction is fetched while another instruction is executing. ![]() Determine the average number of instructions executred each second if the clock ticks at 100MHZ. the HALT instrucion is almost never used ( a maximum of one each program, of course!). the various branches each take out about 5%. the LOAD and STORE instructions each make up about 25% of the instructions in a typical program: ADD, SUBSTRACT, IN, and OUT take 10% each. suppose we are trying to determine the speed of a computer that executes little man instruction set. What happens? what effects does out-of-order execution have upon the time required to execute this program? 3. there are no rename registers, and the CPU retires instructions in order. Now assume that a later instruction in the fetch pipeline has no data dependencies, it adds the value R1, initially to 4, to the value in R4 and stores the result in R5. What is the result? if we define wasted time as time in which an execution unit is not busy, how much time is wasted in this example? b. What is the result? Now assume that the CPU does handle data dependencies correctly. the initial values of R2, R4, AND R5 are 3,8 and 0 respectlively. the CPU does not stall for data dependencies, and both instructions have access to an execution unit simultaneously. the following instruction adds the number in R5 to the number in R2 and stores the result in R5. Now assume the following situation the program is to multiply two numbers, located in registers R2 and R4 and store the results in R5. ![]() An addition instruction requires 2 clock pulses to complete execution, and multiplication requires 15 clock pulses. consider a CPU with two parallel integer execution units. describe, and show in diagram form, what happens when an instruction that requires one execution step follows one that requires four execution steps. The execution unit of this pipeline assumes that the execution stage requires one step. consider a CPU that implements a single fetch-decode-execute-write back pipeline for scalar processing.
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