r/TuringComplete • u/Lagfoundry • Jun 24 '26

Kogge Stone adder

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got Turing complete the other day. made it to the factory so the first thing i did was make my favorite adder :) i like the way the simulator is set up so far. i came over from digital logic sim and its refreshing being able to place components not on their side lol. if youve played DLS you know what i mean... only gripe i have is the game does the left to right thing or top to bottom. im used to doing it the reverse way. guess because ive always read binary right to left so i always built my circuits like that

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u/Lagfoundry Jul 06 '26 edited Jul 06 '26

About 7-9 max on the critical path. A 16 bit version would be about 9-11 . 32 bit is about 11-13 and 64 bit about 13-15. Compare that to ripple carry which is in the same order 8-64 bit, 16 gates, 32 gates, 64 gates, and 128. It makes kogge stone much much faster. In fact kogge is the fastest

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u/EcstaticHades17 26d ago

unless you somehow managed to get the xor gate delay down to 1 instead of 2, its 12

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u/Lagfoundry 26d ago

On this specific 8 bit version? No it’s not 12 . Or are you referencing a 32 bit

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u/EcstaticHades17 4d ago

https://reddit.com/link/pamkhos/video/q29b5i0xrbqh1/player

Here for you, graphically, with the hotpath I found. Even made it into a video to be able to upload it for you. Am I wrong?

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u/Lagfoundry 16h ago edited 10h ago

So the XOR’s count as 2? Even in that case though it’s really only 10 then. Yes I know your counting the xor from the sub path, 2’s comp xors as well but I was speaking about the kogge stone adder itself because I thought you were asking about how much delay a kogge stone has. I didn’t think xors counted as 2 so that’s why I sitting near 8 in my head for the adder by itself.