Optimization level exported as a predefined macro.
__optlevel0 __optlevel1 __optlevel2 __optlevel3 __optlevel4
Using these macros, user can conditionally compile code for a particular optimization level. The following table lists the level of optimization provided by the __optlevelx macro.
| Macro | Optimization Level |
|---|---|
| __optlevel0 | O0 |
| __optlevel1 | O1 |
| __optlevel2 | O2 |
| __optlevel3 | O3 |
| __optlevel4 | O4 |
The listing below shows an example of __optlevelx macro usage.
int main()
{
#if __optlevel0
... // This code compiles only if this code compiled with Optimization
level 0
#elif __optlevel1
... // This code compiles only if this code compiled with Optimization
level 1
#elif __optlevel2
... // This code compiles only if this code compiled with Optimization
level 2
#elif __optlevel3
... // This code compiles only if this code compiled with Optimization
level 3
#elif __optlevel4
... // This code compiles only if this code compiled with Optimization
level 4
#endif
}