In computer architecture, cycles per instruction (CPI) is actually a ratio of two values. The numerator is the number of cpu cycles uses divided by the number of instructions executed. It tells the average number of CPU cycles required to retire an instruction, and therefore is an indicator of how much latency in the system affected the running application and it is the multiplicative inverse of instructions per cycle.
This calculator calculates the cycles per instruction using r-type instructions, load instructions, store instructions, branch instructions, jump instructions values.
Formula:
CPI = ((4xRI) + (5xLI) + (4xSI) + (3xBI) + (3xJI)) / 100
Where,RI is R-type instructions
LI is load instructions
SI is store instructions
BI is branch instructions
JI is jump instructions
Example: If a program has 50% R-type instructions, 10% load instructions, 20% store instructions, 8% branch instructions and 2% jump instructions then what is the CPI?
Solution: CPI = (4x50 + 5x10 + 4x20 + 3x8 + 3x2)/100 = 3.6