Function profiling can help you find the functions in your source code where the most time is spent during execution. You should focus on those functions when optimizing your code. A simple method of optimizing a function is to compile it using speed optimization. Alternatively, you can move the data used by the function into more efficient memory. For detailed information about efficient memory usage, see Efficient coding for embedded applications.

Alternatively, you can use filtered profiling, which means that you can exclude, for example, individual functions from being profiled. To profile only a specific part of your code, you can select a time interval—using the Timeline window—for which C-SPY produces profiling information.

Instruction profiling can help you fine-tune your code on a very detailed level, especially for assembler source code. Instruction profiling can also help you to understand where your compiled C/C++ source code spends most of its time, and perhaps give insight into how to rewrite it for better performance.

Function profiling information is displayed in the Function Profiler window, that is, timing information for the functions in an application. Profiling must be turned on explicitly using a button on the window’s toolbar, and will stay enabled until it is turned off.

For debug probes that support it, C-SPY can capture full instruction trace in real time, and process the information for the Function Profiler window.

Instruction profiling information is displayed in the Disassembly window, that is, the number of times each instruction has been executed.