# Optimization Options

This section contains descriptions for compiler options that pertain to optimization.

Parent topic: Compiler Option Details

- fast
  Maximizes speed across the entire program. This content is specific to C++; it does not apply to DPC++.
- fbuiltin, Oi
  Enables or disables inline expansion of intrinsic functions.
- ffunction-sections
  Places each function in its own COMDAT section.
- foptimize-sibling-calls
  Determines whether the compiler optimizes tail recursive calls.
- GF
  Enables read-only string-pooling optimization.
- nolib-inline
  Disables inline expansion of standard library or intrinsic functions. This content is specific to C++; it does not apply to DPC++.
- O
  Specifies the code optimization for applications.
- Od
  Disables all optimizations.
- Ofast
  Sets certain aggressive options to improve the speed of your application.
- Os
  Enables optimizations that do not increase code size; it produces smaller code size than O2.
- Ot
  Enables all speed optimizations.
- Ox
  Enables maximum optimizations.