java test: unexpected results on AMD CPUs

[biostud]

3/10
Original

It took 17279 milliseconds to complete IntegerLoop.
It took 35492 milliseconds to complete FloatLoop.
It took 8396 milliseconds to complete IntegerLoopNoDiv.
It took 31688 milliseconds to complete FloatLoopNoDiv.
It took 29575 milliseconds to complete CastFloatToInt.
It took 21703 milliseconds to complete CastFloatToIntNoDiv.
It took 75033 milliseconds to complete RoundFloatToInt.
It took 51759 milliseconds to complete RoundFloatToIntNoDiv.
It took 56265 milliseconds to complete CastIntToFloat.
It took 31679 milliseconds to complete CastIntToFloatNoDiv.

Total execution time for your selection is 358869 milliseconds.

Isolated
It took 20 milliseconds to complete integer addition.
It took 19 milliseconds to complete integer multiplication.
It took 47 milliseconds to complete integer division.
It took 22 milliseconds to complete float addition.
It took 200 milliseconds to complete float multiplication.
It took 1963 milliseconds to complete float division.
It took 2734 milliseconds to complete rounding float to integer.
It took 1623 milliseconds to complete casting float to integer.
It took 16 milliseconds to complete casting integer to float.

Total execution time for your selection is 6644 milliseconds.

 

[SlowSpyder]

Just ran the 9/26, clocks at 220MHz x 22 = 4840MHz.

Running original code...
It took 47928 milliseconds to complete IntegerLoop.
It took 70033 milliseconds to complete FloatLoop.
Total execution time for your selection is 117961 milliseconds.

 

[DrMrLordX]

3/10
Original

It took 17279 milliseconds to complete IntegerLoop.
It took 35492 milliseconds to complete FloatLoop.
It took 8396 milliseconds to complete IntegerLoopNoDiv.
It took 31688 milliseconds to complete FloatLoopNoDiv.
It took 29575 milliseconds to complete CastFloatToInt.
It took 21703 milliseconds to complete CastFloatToIntNoDiv.
It took 75033 milliseconds to complete RoundFloatToInt.
It took 51759 milliseconds to complete RoundFloatToIntNoDiv.
It took 56265 milliseconds to complete CastIntToFloat.
It took 31679 milliseconds to complete CastIntToFloatNoDiv.

Total execution time for your selection is 358869 milliseconds.

Okay, this seems normal. But . . .

Isolated
It took 20 milliseconds to complete integer addition.
It took 19 milliseconds to complete integer multiplication.
It took 47 milliseconds to complete integer division.
It took 22 milliseconds to complete float addition.
It took 200 milliseconds to complete float multiplication.
It took 1963 milliseconds to complete float division.
It took 2734 milliseconds to complete rounding float to integer.
It took 1623 milliseconds to complete casting float to integer.
It took 16 milliseconds to complete casting integer to float.

Total execution time for your selection is 6644 milliseconds.

. . . these results are most vexing. Since it's quick, I ran integer addition 10 times and managed an average of ~26 ms. Even if my code has flaws that are causing the VM to throw out instructions in favor of NOPs (which is quite possible), your CPU should still retire NOPs much more quickly than mine. At least twice as quickly, and probably closer to 3-4x faster.

There is something wrong with my code.

Just ran the 9/26, clocks at 220MHz x 22 = 4840MHz.

Running original code...
It took 47928 milliseconds to complete IntegerLoop.
It took 70033 milliseconds to complete FloatLoop.
Total execution time for your selection is 117961 milliseconds.

cool, thanks. You might get a speedup if you run it 2-3 times in succession. You might not.

Try 10/3 if you have the time, it should go faster.