How to benchmark Swift code execution?

Question

Is there a way/software to give precise time needed to execute a block of code written in Swift, other than the following?

let date_start = NSDate()

// Code         


        

Answer 1

I like Brad Larson's answer for a simple test that you can even run in a Playground. For my own needs I've tweaked it a bit:

1. I've wrapped the call to the function I want to test in a testing function, which gives me space to play around with different arguments if I want to.
2. The testing function returns its name, so I don't have to include the 'title' parameter in the averageTimeTo() benchmarking function.
3. The benchmarking function allows you to optionally specify how many repetitions to perform (with a default of 10). It then reports both the total and average times.
4. The benchmarking function prints to the console AND returns the averageTime (which you might expect from a function called 'averageTimeTo'), so there's no need for two separate functions that have almost identical functionality.

For example:

func myFunction(args: Int...) {
    // Do something
}

func testMyFunction() -> String {
    // Wrap the call to myFunction here, and optionally test with different arguments
    myFunction(args: 1, 2, 3)
    return #function
}

// Measure average time to complete test
func averageTimeTo(_ testFunction: () -> String, repeated reps: UInt = 10) -> Double {
    let functionName = testFunction()
    var totalTime = 0.0
    for _ in 0..