### /O Compiler Opton

Syntax: | Default:
/O[+|-]|2|3 | /O-

Use /O to optimize code for speed.

/O2 and /O3 provide the same level of optimization as /O.

Note: The debugger may operate unpredictably with optimized code.

When you specify /O, the following optimization options are set by default:

/Oi | Turn on inlining.
/Os | Invoke the instruction scheduler.
/Oq- | Turn off stackchaining

By default, code is not optimized.

Overview of Optimization

Summary of Compiler Options
Summary of Compiler Options to Enable Optimization