User`s guide

Optimizations Common to All Code Formats
12-25
Select the Inline invariant signals check box. The Real-Time Workshop will
not generate code for blocks with a constant (invariant) sample time.
Select the
Local block outputs check box. Blocks signals will be declared
locally in functions instead of being declared globally (when possible). This
check box is ignored when the
Disable optimized block I/O storage check
box is selected.
Compiler Options
If you do not require double precision for your application, define real_T as
float in your template make file, or you can simply specify -DREAL_T=float
after make_rtw in the Make command field.
Turn on the optimizations for the compiler (e.g.,
-O2 for gcc, -Ot for Microsoft
Visual C).