Optimization-level Options

Option

Description

-O0

Disables optimizations.

-O1

Enables optimizations. Optimizes for speed.  -O1 disables inline expansion of library functions. For Itanium(TM) compiler, -O1 turns off software pipelining to reduce code size.

-O2 Equivalent to option -O1.
-O3 Builds on -O1 and -O2 by enabling high-level optimization. This level does not guarantee higher performance unless loop and memory access transformation take place. In conjunction with -axK/-xK, this switch causes the compiler to perform more aggressive data dependency analysis than for -O2. This may result in longer compilation times.

* -fp is an IA-32 only option and not applicable to compilations targeted for Itanium(TM)-based systems.