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Compiler optimization level

Control application of compiler optimizations

Model Configuration Pane: Code Generation


The Compiler optimization level parameter controls whether the build process applies compiler optimizations.


This parameter appears when the model is configured with a system target file that specifies toolchain-based code generation, as described in Configure Toolchain (ToolchainInfo) or Template Makefile Build Process.


This parameter enables Custom compiler optimization flags.


Optimizations off (faster builds) (default) | Optimizations on (faster runs) | Custom
Optimizations off (faster builds)

Customizes compilation during the build process to minimize compilation time.

Optimizations on (faster runs)

Customizes compilation during the makefile build process to minimize run time.


Allows you to specify custom compiler optimization flags to be applied during the makefile build process. Select this setting for generating code for these types of simulations:

  • Accelerator

  • Rapid accelerator

  • Model reference simulation target

  • Normal mode for Stateflow and the MATLAB Function block

  • MATLAB System block


  • Target-independent values Optimizations on (faster runs) and Optimizations off (faster builds) allow you to easily toggle compiler optimizations on and off during code development.

  • Custom allows you to enter custom compiler optimization flags at Simulink® GUI level, rather than editing compiler flags into template makefiles (TMFs) or supplying compiler flags to make commands.

  • 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.

Recommended Settings

DebuggingOptimizations off (faster builds)
TraceabilityOptimizations off (faster builds)
EfficiencyOptimizations on (faster runs) (execution), No impact (ROM, RAM)
Safety precautionNo impact

Programmatic Use

Parameter: RTWCompilerOptimization
Type: character vector
Value: 'off' | 'on' | 'custom'
Default: 'off'

Version History

Introduced in R2007b