/O Options (Optimize Code)
The /O options control various optimizations that help you create code for maximum speed or minimum size.
/O1 sets a combination of optimizations that generate minimum size code.
/O2 sets a combination of optimizations that optimizes code for maximum speed.
/Ob controls inline function expansion.
/Od disables optimization, to speed compilation and simplify 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 is a combination option that selects several of the optimizations with an emphasis on speed. It is a strict subset of the /O2 optimizations.
/Oy suppresses the creation of frame pointers on the call stack for quicker function calls.
You can combine multiple /O options into a single option statement. For example, /Odi is the same as /Od /Oi. Certain options are mutually exclusive and cause a compiler error if used together. See the individual /O options for more information.