Merge pull request #51 from invariant-labs/refactor-get-next-sqrt-pri…

…ce-y-down Refactor getNextSqrtPriceYDown
invariant-labs · Apr 13, 2024 · f0e8f30 · f0e8f30
2 parents adf4158 + edfa1c1
commit f0e8f30
Show file tree

Hide file tree

Showing 7 changed files with 1,659 additions and 1,386 deletions.
diff --git a/contracts/math/clamm.ral b/contracts/math/clamm.ral
@@ -204,13 +204,13 @@ Contract CLAMM(uints: Uints) extends Log(uints){
         y: U256,
         addY: Bool
     ) -> U256 {
-        let numerator = rescale(y, TokenAmountScale, SqrtPriceScale)
-        let denominator = rescale(liquidity, LiquidityScale, SqrtPriceScale)
-
+        let numerator = uints.bigRescale(y, TokenAmountScale, SqrtPriceScale)
+        let denominator = uints.bigRescale(liquidity, LiquidityScale, SqrtPriceScale)
+        
         if (addY) {
-            return startingSqrtPrice + div(numerator, denominator)
+            return startingSqrtPrice + uints.toU256(uints.bigDiv512(numerator, denominator, one(SqrtPriceScale)))
         } else {
-            return startingSqrtPrice - divUp(numerator, denominator)
+            return startingSqrtPrice - uints.toU256(uints.bigDivUp512(numerator, denominator, one(SqrtPriceScale)))
         }
 
     }

diff --git a/contracts/math/uints.ral b/contracts/math/uints.ral
@@ -152,6 +152,55 @@ Contract Uints () {
         return bigDivWrapper(result, b, 1)
     }
 
+    pub fn bigDiv512(dividend: U512, divisor: U512, divisorDenominator: U256) -> U512 {
+        let mut q = U512 { higher: 0, lower: 0 }
+        let mut r = U512 { higher: 0, lower: 0 }
+
+        assert!(!isZero(divisor), ArithmeticError.DivNotPositiveDivisor)
+        assert!(divisorDenominator != 0, ArithmeticError.DivNotPositiveDenominator)
+
+        let extDividend = bigMul(dividend, divisorDenominator)
+        let mut uHigh = extDividend.higher
+        let mut uLow = extDividend.lower
+
+        let v = divisor
+
+        let mut j = 512
+        while (j > 0) {
+            j = j - 1
+            r = bigShl(r, 1)
+
+            if (((uHigh >> 255) & 1) != 0) {
+                r = bitOrLower(r, 1)
+            }
+
+            uHigh = uHigh << 1
+
+            if ((uLow >> 255) != 0) {
+                uHigh = uHigh | 1
+            }
+            uLow = uLow << 1
+
+            if (isGreaterEqual(r,v)) {
+                r = bigSub512(r, v)
+                if (j >= 256) {
+                    q.higher = q.higher | (1 << (j - 256))
+                } else {
+                    q.lower = q.lower | (1 << j)
+                }
+            }
+        }
+
+        return q
+    }
+
+    pub fn bigDivUp512(dividend: U512, divisor: U512, divisorDenominator: U256) -> U512 {
+        let mut result = bigMul(dividend, divisorDenominator)
+        result = bigAdd512(result, divisor)
+        result.lower = result.lower - 1
+        return bigDiv512(result, divisor, 1)
+    }
+
     pub fn bigMul256(a: U256, b: U256) -> U512 {
         let aLower = low128(a)
         let aHigher = high128(a)
@@ -208,9 +257,8 @@ Contract Uints () {
     pub fn overflowingAdd(a: U256, b: U256) -> (U256, U256) {
         if (MaxU256 - a >= b) {
             return a + b, 0
-        }
-
-        if (a > b) {
+        } 
+        if (a > b){ 
             return a - (MaxU256 - b) - 1, 1
         } else {
             return b - (MaxU256 - a) - 1, 1
@@ -293,69 +341,5 @@ Contract Uints () {
     pub fn isZero(a: U512) -> Bool {
         return a.higher == 0 && a.lower == 0
     }
-
-    pub fn bigDiv512(dividend: U512, divisor: U512, divisorDenominator: U256) -> U512 {
-        let mut q = U512 { higher: 0, lower: 0 }
-        let mut r = U512 { higher: 0, lower: 0 }
-
-        assert!(!isZero(divisor), ArithmeticError.DivNotPositiveDivisor)
-        assert!(divisorDenominator > 0, ArithmeticError.DivNotPositiveDenominator)
-
-        if (dividend.higher == 0) {
-            let mulResult = bigMul256(dividend.lower, divisorDenominator)
-
-            if (mulResult.higher == 0) {
-                return U512 { higher: 0, lower: mulResult.lower / divisor.lower }
-            }
-            let divResult = bigDiv512(mulResult, divisor, 1)
-            return divResult
-        }
-
-        let mut uHigh = dividend.higher * divisorDenominator
-        let mut uLow = dividend.lower * divisorDenominator
-        let v = divisor
-
-        for (let mut j = 511; j > 0; j = j - 1) {
-            r.lower = r.lower << 1 | (r.higher >> 255)
-            r.higher = r.higher << 1
-
-            if (((uHigh >> 255) & 1) != 0) {
-                r.lower = r.lower | 1
-            }
-
-            uHigh = uHigh << 1
-
-            if ((uLow >> 255) != 0) {
-                uHigh = uHigh | 1
-            }
-            uLow = uLow << 1
-
-            if (r.higher > v.higher || (r.higher == v.higher && r.lower >= v.lower)) {
-                let mut borrow = 1
-
-                if (r.lower >= v.lower) {
-                    borrow = 0
-                }
-
-                r.lower = r.lower - (v.lower + borrow)
-                r.higher = r.higher - (v.higher + borrow)
-
-                if (j >= 256) {
-                    q.higher = q.higher | (1 << (j - 256))
-                } else {
-                    q.lower = q.lower | (1 << j)
-                }
-            }
-        }
-
-        return q
-    }
-
-    pub fn bigDivUp512(dividend: U512, divisor: U512, divisorDenominator: U256) -> U512 {
-        let mut result = bigMul(dividend, divisorDenominator)
-        result = bigAdd512(result, divisor)
-        result.lower = result.lower - 1
-        return bigDiv512(result, divisor, 1)
-    }
 }