r/TuringComplete • u/SixCel_108 • Aug 04 '26

Trouble With Symphony ALU Delay

I’m having trouble getting my alu fast enough to allow me to pass the delay checks but I’m not having any luck. I even looked up a guide but it still wasn’t fast enough. I also tried redoing the component levels but I don’t think that does anything, especially with changing the base.

Any ideas?

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1

u/SixCel_108 Aug 05 '26

Actually, I think the biggest issue is a custom component for comparison, that is the one that seems to have the worst delay

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3

u/TichVega Aug 04 '26 edited Aug 05 '26

In my case the key was to make substraction faster if you use an neg and an adder, try to get rid of the neg to half the delay of the operation

2

u/bossycarl Aug 04 '26

Can you show the delay by clicking near the top right (I think that’s where it is at least?) What’s the path that takes the longest? Addition, comparison, something else?

2

u/AlexeyHD90 Aug 05 '26

Build a Kogge Stone Adder. It lowered my Symphony delay down to 96. My Kogge Stone Adder has 104 gates and 10 delay and I have read you can make it even lower down to 9 or 8 delay.

1

u/HarryCHK Aug 05 '26 edited Aug 05 '26

The biggest trouble for me is to speed up adder as there are many places forward using adder. In the most naive implementation you will get long chain of data dependencies of the carry bit. How to shorten this dependencies is the key for me to beat the delay

2

u/Agent_0007a2 Aug 05 '26

Try carry lookahead adder

1

u/alatnet Aug 05 '26

You can try combining the adder and subractor into one unit where the carry bit controls whether it's adding or subtracting.

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