WWDC 2015 Optimizing Swift Performance

Xcode compiles file independently.

Reference Counting

Var x: C? = C() RC += 1
Var y: C? = x  RC += 1
foo(y)

Y = nil
X = nil

Whole Module Optimization
Using it all files are complied together, so that definition from other file can be visible in other files

Inheritance
Using final keyword

Access Control
private keyword cannot be access from other module

Enable Whole Module Optimization for better compiling!

Actual adaption to our App.

Changed No Optimization -> Opitimize for Speed

Changed LLVM Optimization None -> Fastest, Aggressive Optimization

Added these two changes to our code and complie time got 80% faster.
Only changed Debug and Dev version to avoid in case error at released app.