[jpatte]

For those wondering (spoilers), the puzzle he's talking about in section 2 ("the second puzzle in the game") is a simple puzzle where you just have to double the values provided as input to produce an output. The naive solution at 240 points he mentions is extremely straightforward:

  mov p0 acc  # place input value into internal register
  mul 2       # multiply register by 2
  mov acc p1  # place register value into output
  slp 1       # sleep 1 cycle, wait for next input

The only way (I can think of) to optimize this is by cheating, i.e. by writing an algorithm specifically fitted for the kind of input we have to deal with. Looking at the input, we see that for example there are only 3 input values (0, 25 and 50) and there seems to be more zeros than other values. Based on this info we can try to predict what value is likely to show up as input and follow a dedicated path to handle it, in order to be as efficient as possible.

I must admit I was happy with the 240 solution and never thought there was a better way until I read this article. Now I feel obliged to at least go down to 156 :D

[jessermeyer]

>The only way (I can think of) to optimize this is by cheating, i.e. by writing an algorithm specifically fitted for the kind of input we have to deal with.

Programmers must stop equating cheating with engineering.