How to Dramatically Increase Efficiency of Simulink Generated Code in Two Clicks!
This article will show you how to make C code generated from MATLAB and Simulink dramatically more efficient with two simple clicks! A recent user question shows that it is easy to be unaware of this powerful capability. This article will show a modeling utility that makes it easy to see the cause of the inefficiency and how to correct it.
The user wanted code like the following 60+ lines to be more efficient.
By dropping a utility block on the model, the missed opportunity becomes readily apparent.
The code generation target is configured to use an ARM Cortex, but it has not been configured to make the 64 bit long long data type available. The long long data type officially became part of the C standard way back in 1999. The long long data type has been supported by Embedded Coder and by ARM Compilers for many years. There does not seem to be any good reason not to exploit compiler supported access to 64 bit integer types. (If you are stuck to 30 year old 1989 C standard or have another reason you cannot use long long, please send me a message and let me know your use case.)
To leverage long long, simply click on the red block, to open the Configuration Parameters dialog to the critical parameter.
Once support for long long is enabled, the utility block will turn a happy green.
More importantly, if Embedded Coder is used to regenerate code, it will be dramatically more efficient. In fact, it will be comprised of just one simple expression.
It doesn’t get much easier than that. With literally two clicks, the long long data type was enabled for C code generation from the Simulink model. For math operations that require 64 bit integer or fixed-point math, utilizing long long can dramatically improve efficiency. For the example shown, the improvement was roughly 60X. Not bad for two clicks.
Thank you for reading,
Andy Bartlett
PS: If you’d like to play with this example, you can get the examples shown on GitHub.
The example models and library block will be found in the folder named MoreEfficientCodeInTwoClicks.
Models are provided that can be used in release R2015a or newer.
Copyright 2019-2020 The MathWorks, Inc.
Director Consulting Services
5yThanks for sharing Andy;) this really makes a huge difference;) please keep these features coming;) would be curious to know about what is new in R2020a;)