Haven't done machine code since my Apple ][ days. Assembly, however is still heavily used in embedded systems. Most commonly in boot code and interrupt handlers

Haven't done machine code since my Apple ][ days. Assembly, however is still heavily used in embedded systems. Most commonly in boot code and interrupt handlers. Handcrafting inner loops for DSP applications is also still common. The percentage of assembly in my projects is typically very small, I'm sure it's way less than 1% in my case. Another area where assembly is still common is around specialized HW features, e.g. putting the processor into low power modes or other situations where specific instructions have to be issued in a specific order. For speed optimisation more often than not I start out with the output of the C compiler to see where I can optimize.