Core 2 Duo should have at least 2-3 integer funtion units , and it can fetch and decode at least 3-4 ops per cycle . But I made some experiments on my laptop which is core 2 duo . I really can't understand the results. some one can give me help ?
the main loop is as following
addl $1,%eax # [0]
cmpl %esi,%eax # [1]
jl .Lt_11_4354 # [77] runtime 0.46s
I add 1 to 7 "nop" ops in it , the runtime will increase from 0.63s to 1.36s step by step . This result shows that nop can't be handled more in parallel ?
When I substitute nop with integer addl, the same thing happen .
How to understand on Core 2 Duo . The results show a different core type which is difficult to understand ? Could Some one please give me some suggestion?
CPU: Intel(R) Core(TM)2 Duo CPU T8100 @ 2.10GHz
OS: federa ,Linux version 2.6.33.3-85.fc13.x86_64
