/O Options (Optimize Code)
The /O options control various optimizations that help you create code for maximum speed or minimum size.
/O1 optimizes code for minimum size.
/O2 optimizes code for maximum speed.
/Ob controls inline function expansion.
/Od disables optimization, speeding compilation and simplifying debugging.
/Og enables global optimizations.
/Oi generates intrinsic functions for appropriate function calls.
/Os tells the compiler to favor optimizations for size over optimizations for speed.
/Ot (a default setting) tells the compiler to favor optimizations for speed over optimizations for size.
/Ox selects full optimization.
/Oy suppresses the creation of frame pointers on the call stack for quicker function calls.
You can also combine multiple /O options into a single option statement. For example, /Odi is the same as /Od /Oi.