Check the documentation of libepc.h here to find how to count the number cycles, or the time in milliseconds, when you compare the C (optimized/non-optimized) and assembly versions of your llmultiply method.

Observe the main function appends to the "outputLog.txt" file. Do not forget to delete outputLog.txt to get a fresh one for comparison with the reference file. Also, when redirecting the output of your program from the command line (as in "a.out > displayLog.txt"), you want to use ">" and not ">>" which appends to the old content (instead of replacing as you want for comparison).