LSL Script Efficiency

What is Efficiency

Efficiency is how long it takes to run a script.

There are many ways to speed up scripts, such as using ++a instead of a++.

Rules for posting

The following code snipit will allow testing of a function.

integer time() {
    string stamp = llGetTimestamp();
    return (integer) llGetSubString(stamp, 11, 12) * 3600000 + (integer) llGetSubString(stamp, 14, 15) * 60000 + llRound((float)llGetSubString(stamp, 17, -2) * 1000000.0)/1000;
}


default {
  state_entry() {
    float i = 0;
    float max = 10000;
    float current = time();
    while (i < max) {
      ++i;
    }
    float t = (time()+-current)/max;
    llOwnerSay("The function in the loop took a total of " + (string)t + " milliseconds.");
  }
}

Efficiency

In theory, ++a and a += 1 are equal in speed, however this is not true:

  ++a:     0.364700 millis
  a += 1:  0.346900 millis
  a++:     0.413700 millis

Testing the same function in for loops:

  ++a:     0.358370 millis
  a += 1:  0.351200 millis
  a++:     0.424600 millis