See the Optimization Levels section for more information.
Option |
Description |
Default |
|
-O1 |
IA-32 compiler: Optimizes to favor code size. Disables option -fp. Disables intrinsics inlining to reduce code size. Itanium(TM)
compiler: Turns off software pipelining to reduce code size. Optimizes
to favor code size. Enables the same optimizations as -O2
except for loop unrolling. |
OFF |
|
-O, -O2 |
Optimize for speed, but disable some optimizations that increase code size for a small speed benefit. -O2 disables option -fp. |
-O2 |
|
-O3 |
Enables -O2 option with more aggressive optimization
and sets high-level optimizations, including loop transformation, OpenMP,
and prefetching. High-level optimizations use the properties of source
code constructs such as loops and arrays in applications written in high-level
programming languages. |
OFF |
|
-O0 |
Disables optimizations -O1, -O2 and -O3. Enables option -fp. |
OFF |