⚡️ Optimize Pow2 Padding (#1464)

Author: 0xClandestine

src/utils/MerkleTreeLib.sol

@@ -262,8 +262,9 @@ library MerkleTreeLib {
                 mstore(0x00, 0xe7171dc4) // `MerkleTreeLeavesEmpty()`.
                 revert(0x1c, 0x04)
             }
-            let p := 1 // Padded length.
-            for {} lt(p, l) {} { p := add(p, p) }
+            let p := sub(mload(leaves), 1)
+            for { let i := 1 } lt(i, 0x80) { i := add(i, i) } { p := or(p, shr(i, p)) }
+            p := add(p, 1)
             mstore(result, p) // Store length.
             mstore(0x40, add(result, add(0x20, shl(5, p)))) // Allocate memory.
             let d := sub(result, leaves)