This sample script is for measuring the execution time of built-in functions for Google Spreadsheet. Unfortunately, there are not measurement tools for retrieving the execution time of built-in functions. So I thought of about a workaround.
Flow :
- Import a value to a cell. The value is anything good, because this is used as a trigger. Please do this by yourself.
- Custom functions cannot use setValue(). So I usedonEdit().
 
- Custom functions cannot use 
- func1()imports a formula that you want to measure the execution time by the script launched by the trigger.
- At func2(), after set the formula, the measurement is started. The confirmation when built-in function was completed is carried out using loop.- By measuring the cost per one call for getValue(), it was found that that was about 0.0003 s. So I thought that this can be used.
 
- By measuring the cost per one call for 
- The result of measurement can be seen at Stackdriver as milliseconds.
Sample script :
function func1(range, formula) {
  range.setFormula(formula);
}
function func2(range) {
  var d = range.getValue();
  while (r == d) {
    var r = range.getValue();
  }
}
function onEdit() {
  var formula = '### Built-in function ###'; // Set the built-in function you want to measure.
  var label = "Execution time for built-in functions.";
  var ss = SpreadsheetApp.getActiveSheet();
  var cell = ss.getActiveCell();
  var range = ss.getRange(cell.getRow(), cell.getColumn());
  func1(range, formula);
  console.time(label);
  func2(range);
  console.timeEnd(label);
}
Note :
- When built-in functions with very long time is measured, an error may occur at getValue().- In my environment, the built-in function for 10 seconds worked fine.