> It turns out that multiplying cracovians by computers is not faster than multiplying matrices. That's very specific of Python. A few years ago we were multip

> It turns out that multiplying cracovians by computers is not faster than multiplying matrices. That's very specific of Python. A few years ago we were multiplying a lot of matrices in Fortran and we tried to transpose one of the matrices before the multiplication. With -o0 it was a huge difference because the calculation used contiguous numbers and was more chache friendly. Anyway, with -o3 the compiler made some trick that made the difference disappear, but I never tried to understand what the compiler was doing.