Xcode 5 and LLVM Build Recommendation both iOS and OSX

- Turn On below feature for optimization

1. Enforce Strict Aliasing

YES (Default YES)

2. Link-Time Optimization(LTO)

YES (Default NO)

3. Vectorize Loops

YES (Default NO)

4. Optimization Level :

-Ofast (Default release -Os)

*Caution
  1) Do not use if your application has high level floating point precision requirement
  2) Does not enable LTO(2.)
  3) Test Carefully

--> For best performance : Two options
 -Ofast or -O3 with LTO

- Use Static Analyzer

- Warnings : Documentation Comments



From : WWDC 2013 -  402 What's New in the LLVM Compiler
                                      408 Optimize Your Code Using LLVM