There are some MicroPython viper code examples in this repository:

• signal_processing/fft_int.py: a integer FFT (Fast Fourier Transform), with von Hann windowing, in viper code
• signal_processing/autocorrelation.py: autocorrelation noise reduction algorithm, implemented in viper code

The rest are exercises to find out how viper works. The conclusions of these tests are at https://github.com/micropython/micropython/wiki/Improving-performance-with-Viper-code

• classes.py: viper decorator in the context of classes
• example.py: the examples here
• global_nonlocal.py: tests of viper for global and nonlocal variables
• int_uint_test.py: tests of int/uint behaviour
• integer_expressions.py: viper and builtins.int integer expressions
• odd_addresses.py: my ESP32-S3 crashes with this script
• testviper.py: Many tests
• tuples_and_lists.py: viper ints in tuples and lists
• viper_native.py: Comparison of times between viper and undecorated. Call function overhead.