/O options (Optimize code)
The /O options control various optimizations that help you create code for maximum speed or minimum size.
/O1sets a combination of optimizations that generate minimum size code./O2sets a combination of optimizations that optimizes code for maximum speed./Obcontrols inline function expansion./Oddisables optimization, to speed compilation and simplify debugging./Og(deprecated) enables global optimizations./Oigenerates intrinsic functions for appropriate function calls./Ostells 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./Oxis a combination option that selects several of the optimizations with an emphasis on speed./Oxis a strict subset of the/O2optimizations./Oysuppresses the creation of frame pointers on the call stack for quicker function calls.
Remarks
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. For more information, see the individual /O options.