balanced pair optimization

test/GasTest.sol

@@ -162,7 +162,42 @@ contract GasTest is Test {
         // Deploy pool with a small fee to test fee-handling paths (use 1000 ppm = 0.1%)
         uint256 feePpm = 1000;
         string memory poolName = string(abi.encodePacked("LP", vm.toString(numTokens)));
-        PartyPool newPool = new PartyPool(poolName, poolName, tokens, bases, tradeFrac, targetSlippage, feePpm, feePpm);
+        PartyPool newPool = new PartyPool(poolName, poolName, tokens, bases, tradeFrac, targetSlippage, feePpm, feePpm, false);
+
+        // Transfer initial deposit amounts into pool before initial mint
+        for (uint256 i = 0; i < numTokens; i++) {
+            TestERC20(tokens[i]).transfer(address(newPool), INIT_BAL);
+        }
+
+        // Perform initial mint (initial deposit); receiver is this contract
+        newPool.mint(address(0), address(this), 0, 0);
+
+        return newPool;
+    }
+
+    /// @notice Helper to create a pool with the stable-pair optimization enabled
+    function createPoolStable(uint256 numTokens) internal returns (PartyPool) {
+        // Deploy tokens dynamically
+        address[] memory tokens = new address[](numTokens);
+        uint256[] memory bases = new uint256[](numTokens);
+
+        for (uint256 i = 0; i < numTokens; i++) {
+            string memory name = string(abi.encodePacked("T", vm.toString(i)));
+            TestERC20 token = new TestERC20(name, name, 0);
+            tokens[i] = address(token);
+            bases[i] = BASE;
+
+            // Mint initial balances for pool initialization and test users
+            token.mint(address(this), INIT_BAL);
+            token.mint(alice, INIT_BAL);
+            token.mint(bob, INIT_BAL);
+        }
+
+        // Deploy pool with a small fee to test fee-handling paths (use 1000 ppm = 0.1%)
+        uint256 feePpm = 1000;
+        string memory poolName = string(abi.encodePacked("LPs", vm.toString(numTokens)));
+        // Note the final 'true' arg to activate stable-pair optimization path
+        PartyPool newPool = new PartyPool(poolName, poolName, tokens, bases, tradeFrac, targetSlippage, feePpm, feePpm, true);
 
         // Transfer initial deposit amounts into pool before initial mint
         for (uint256 i = 0; i < numTokens; i++) {
@@ -253,6 +288,24 @@ contract GasTest is Test {
         _performSwapGasTest(pool50);
     }
 
+    /// @notice Gas measurement: perform 10 swaps back-and-forth on a 2-token stable pair (stable-path enabled)
+    function testSwapGasStablePair() public {
+        PartyPool stablePair = createPoolStable(2);
+        _performSwapGasTest(stablePair);
+    }
+
+    /// @notice Gas-style test: alternate swapMint then burnSwap on a 2-token stable pair
+    function testSwapMintBurnSwapGasStablePair() public {
+        PartyPool stablePair = createPoolStable(2);
+        _performSwapMintBurnSwapGasTest(stablePair);
+    }
+
+    /// @notice Combined gas test (mint then burn) on 2-token stable pair using mint() and burn().
+    function testMintBurnGasStablePair() public {
+        PartyPool stablePair = createPoolStable(2);
+        _performMintBurnGasTest(stablePair);
+    }
+
     /// @notice Helper function: alternate swapMint then burnSwap to keep pool size roughly stable.
     function _performSwapMintBurnSwapGasTest(PartyPool testPool) internal {
         uint256 iterations = 10;