To show Xcode build time, from the Terminal, run the below command.

defaults write com.apple.dt.Xcode ShowBuildOperationDuration -bool YES

After which running Xcode builds will display the time in the info bar. To get the full build time, clean the project and build again.

To get the dynamic linked framework startup time, add DYLD_PRINT_STATISTICS environment variable with value as 1. Environment variables can be added from the Run section by editing the target's schema from Xcode.