Update contracts/utils/math/SignedMath.sol

Co-authored-by: Francisco Giordano <[email protected]>
OpenZeppelin · Jan 7, 2022 · 4299249 · 4299249
1 parent 39ea6c8
commit 4299249
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/contracts/utils/math/SignedMath.sol b/contracts/utils/math/SignedMath.sol
@@ -21,11 +21,11 @@ library SignedMath {
     }
 
     /**
-     * @dev Returns the average of two signed numbers. The result is rounded
-     * towards zero.
+     * @dev Returns the average of two signed numbers without overflow.
+     * The result is rounded towards zero.
      */
     function average(int256 a, int256 b) internal pure returns (int256) {
-        // (a + b) / 2 can overflow, and the unsigned formula doesn't simply translate to signed integers
+        // Formula from the book "Hacker's Delight"
         int256 x = (a & b) + ((a ^ b) >> 1);
         return x + (int256(uint256(x) >> 255) & (a ^ b));
     }