Os

Enables optimizations that do not increase code size; it produces smaller code size than O2.

Syntax

Linux and macOS:

-Os

Windows:

/Os

Arguments

None

Default

OFF	Optimizations are made for code speed. However, if O1 is specified, Os is the default.

Description

This option enables optimizations that do not increase code size; it produces smaller code size than O2. It disables some optimizations that increase code size for a small speed benefit.

This option tells the compiler to favor transformations that reduce code size over transformations that produce maximum performance.

IDE Equivalent

Visual Studio: Optimization > Favor Size or Speed

Eclipse: None

Xcode: None

Alternate Options