To control compiler optimizations for a makefile build at the GUI level, use the Compiler optimization level parameter. The Compiler optimization level parameter provides
Target-independent values Optimizations on (faster runs) and
Optimizations off (faster
builds), which allow you to easily
toggle compiler optimizations on and off during code
development
The value Custom for entering custom compiler optimization flags at
the Simulink® GUI level, rather than editing compiler flags
into template makefiles (TMFs) or supplying compiler flags
to build process make commands
The default setting is Optimizations off (faster builds). Selecting
the value Custom enables the Custom
compiler optimization flags field, in which you can enter
custom compiler optimization flags (for example,
-O2).
If you specify compiler options for your makefile build using
OPT_OPTS, MEX_OPTS (except
MEX_OPTS="-v"), or
MEX_OPT_FILE, the value of Compiler
optimization level is ignored and a warning is issued
about the ignored parameter.
For a rapid simulation (Simulink Coder) that uses the MinGW® compiler:
If RTWCompilerOptimization (Simulink Coder) is set
to 'on', the build process
customizes compiler optimization to minimize run
time. The build process ignores the BuildConfiguration (Simulink Coder) and
CustomToolchainOptions (Simulink Coder)
settings.
If RTWCompilerOptimization is set
to 'custom' or
'off', the build process uses
BuildConfiguration and
CustomToolchainOptions
settings. The build process ignores the
RTWCompilerOptimization
setting.