We are trying to implement AMM (Automated Market Maker) DEX in TEAL. Not sure how much into the details should I go but the problem that we are facing right now is that, we need to calculate proportion of assets that are already in the pool to the asset being added to the pool and from that we can …

I think you would avoid losing precision by also talking the modulo when performing that initial division, and use that fractional part in the later multiplication.

Let’s pretend TEAL only supported u16, so the numbers are small. I think you’re asking how you should calculate (2^8/2^9)(2^8+1). Which is (256/513)(258) = 128r384 How can we get 128r384 using only what TEAL has? I changed the calculation slightly to be a better illustration. Dividing by 513 ma…

I’m not all convinced this always works. The low word could be nearly too big, so when you bring the bits down from the high word, you get addition overflow.

Thank you. This looks like a right way to go, I will give it a try and think what to do with that one overflow. Still it looks like a quite a work to common math/finance problem that eventually most of more advanced smart contracts would end up. Regarding extra opcodes. Adding divw would definitel…

With divmodw and callsub/retsub released to betanet… func TestMulDiv(t *testing.T) { // Demonstrate a "function" that expects three u64s on stack, // and calculates B*C/A. (Following opcode documentaion // convention, C is top-of-stack, B is below it, and A is // below B. muldiv := ` muldiv: …

128-bit TEAL operations

General

krotkiewicz March 4, 2021, 4:13pm 3

Ok, that make sense but what in case we have such numbers? I am getting either 0 or overflow.

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128-bit TEAL operations

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