Vector Operation Optimization
This example shows how Simulink® Coder™ optimizes generated code by setting block output that generates vectors to scalars, for blocks such as the Mux, Sum, Gain, and Bus. This optimization reduces stack memory by replacing temporary local arrays with local variables.
Example Model
In the model, rtwdemo_VectorOptimization, the output of Gain blocks G1 and G2 are the vector signals tmp1 and tmp2. These vectors have a width of 10.
model = 'rtwdemo_VectorOptimization'; open_system(model); set_param(model, 'SimulationCommand', 'update')
Generate Code
Create a temporary folder (in your system temporary folder) for the build and inspection process.
currentDir = pwd; [~,cgDir] = rtwdemodir();
Build the model.
rtwbuild(model)
### Starting build procedure for: rtwdemo_VectorOptimization ### Successful completion of build procedure for: rtwdemo_VectorOptimization Build Summary Top model targets built: Model Action Rebuild Reason =========================================================================================================== rtwdemo_VectorOptimization Code generated and compiled Code generation information file does not exist. 1 of 1 models built (0 models already up to date) Build duration: 0h 0m 17.851s
The optimized code is in rtwdemo_VectorOptimization.c. The signals tmp1 and tmp2 are the local variables rtb_tmp1 and rtb_tmp2.
cfile = fullfile(cgDir,'rtwdemo_VectorOptimization_grt_rtw',... 'rtwdemo_VectorOptimization.c'); rtwdemodbtype(cfile,'/* Model step', '/* Model initialize', 1, 0);
/* Model step function */
void rtwdemo_VectorOptimization_step(void)
{
real_T rtb_Sum3;
real_T rtb_tmp1;
real_T rtb_tmp2;
int32_T i;
for (i = 0; i < 10; i++) {
/* Gain: '<Root>/G2' incorporates:
* UnitDelay: '<Root>/X2'
*/
rtb_tmp2 = 0.3 * rtwdemo_VectorOptimization_DW.X2_DSTATE[i];
/* Gain: '<Root>/G1' incorporates:
* UnitDelay: '<Root>/X1'
*/
rtb_tmp1 = 0.2 * rtwdemo_VectorOptimization_DW.X1_DSTATE[i];
/* Sum: '<Root>/Sum3' incorporates:
* Gain: '<Root>/G3'
* Inport: '<Root>/In2'
* Sum: '<Root>/Sum1'
* Sum: '<Root>/Sum2'
* UnitDelay: '<Root>/X3'
*/
rtb_Sum3 = ((rtwdemo_VectorOptimization_U.In2[i] - 0.4 *
rtwdemo_VectorOptimization_DW.X3_DSTATE[i]) - rtb_tmp2) -
rtb_tmp1;
/* Outport: '<Root>/Out2' */
rtwdemo_VectorOptimization_Y.Out2[i] = rtb_Sum3;
/* Update for UnitDelay: '<Root>/X3' */
rtwdemo_VectorOptimization_DW.X3_DSTATE[i] = rtb_tmp2;
/* Update for UnitDelay: '<Root>/X2' */
rtwdemo_VectorOptimization_DW.X2_DSTATE[i] = rtb_tmp1;
/* Update for UnitDelay: '<Root>/X1' */
rtwdemo_VectorOptimization_DW.X1_DSTATE[i] = rtb_Sum3;
}
}
Close the model and code generation report.
bdclose(model) rtwdemoclean; cd(currentDir)