Let's recount the classic embedded system optimizations. These are as follows:
- Minimizing executable size
- Minimizing memory usage, removing dynamic allocations
- Optimizing your math: Looking for fast and slow instructions, using fake or low-precision floating-point calculations, modifying algorithms
- Lowering power consumption: Turning off unused hardware, slowing down to save battery, putting the processor to sleep
Although the hardware where Qt is running doesn't require drastic optimizations, many of the classic techniques are still used. Let's look at some examples to illustrate that fact.