Runtime of DSP-Code Increased after Upgrade to 2017a

Hi

I am generating Code for a DSP-system using the Code Generator in Simulink. After the Upgrade from Matlab 2016b to 2017a the code runs slower on the DSP. I generated the Code from the exact same Model once with 2016b and once with 2017a.

The running time increased by about 10% (tested several times independently), which is a problem because runtime is important in this application. I even tried to increase performance by using the Code Generation Settings and the objective "Execution efficiency", without any success. Matlab 2017a is needed to open other projects created by colleagues, so going back to 2016b is not an option.

Are there any known differences in the Simulink Code Generation between 2016b and 2017a and if so is there a possibility to use the Code Generation of 2016b with 2017a.

EDIT:

After some examination of the generated C-Code I have the assumption that the increase in running time is due to the change of the Simulink coder (Real-Time Workshop) or the TLC version. Matlab 2017a uses the Real-Time Workshop file version 8.12 and the TLC version 8.12, whereas 2016b uses 8.11. I don’t say the newer Version is worse than the old one, but with my particular model it generates a more inefficient Code. Unfortunately, I haven’t found an option to choose the older Simulink Coder Version in 2017a. Is there a possibility to do so?

I would appreciate any suggestions.

Many thanks and a nice day!