fix: Make WadRayMath and PercentageMath unchecked

aave · Jul 28, 2021 · 1a81ecf · 1a81ecf
1 parent 932f591
commit 1a81ecf
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Showing 3 changed files with 57 additions and 41 deletions.
diff --git a/contracts/protocol/libraries/math/PercentageMath.sol b/contracts/protocol/libraries/math/PercentageMath.sol
@@ -22,16 +22,18 @@ library PercentageMath {
    * @return The percentage of value
    **/
   function percentMul(uint256 value, uint256 percentage) internal pure returns (uint256) {
-    if (value == 0 || percentage == 0) {
-      return 0;
-    }
+    unchecked {
+      if (value == 0 || percentage == 0) {
+        return 0;
+      }
 
-    require(
-      value <= (type(uint256).max - HALF_PERCENT) / percentage,
-      Errors.MATH_MULTIPLICATION_OVERFLOW
-    );
+      require(
+        value <= (type(uint256).max - HALF_PERCENT) / percentage,
+        Errors.MATH_MULTIPLICATION_OVERFLOW
+      );
 
-    return (value * percentage + HALF_PERCENT) / PERCENTAGE_FACTOR;
+      return (value * percentage + HALF_PERCENT) / PERCENTAGE_FACTOR;
+    }
   }
 
   /**
@@ -41,14 +43,16 @@ library PercentageMath {
    * @return The value divided the percentage
    **/
   function percentDiv(uint256 value, uint256 percentage) internal pure returns (uint256) {
-    require(percentage != 0, Errors.MATH_DIVISION_BY_ZERO);
-    uint256 halfPercentage = percentage / 2;
+    unchecked {
+      require(percentage != 0, Errors.MATH_DIVISION_BY_ZERO);
+      uint256 halfPercentage = percentage / 2;
 
-    require(
-      value <= (type(uint256).max - halfPercentage) / PERCENTAGE_FACTOR,
-      Errors.MATH_MULTIPLICATION_OVERFLOW
-    );
+      require(
+        value <= (type(uint256).max - halfPercentage) / PERCENTAGE_FACTOR,
+        Errors.MATH_MULTIPLICATION_OVERFLOW
+      );
 
-    return (value * PERCENTAGE_FACTOR + halfPercentage) / percentage;
+      return (value * PERCENTAGE_FACTOR + halfPercentage) / percentage;
+    }
   }
 }
diff --git a/contracts/protocol/libraries/math/WadRayMath.sol b/contracts/protocol/libraries/math/WadRayMath.sol
@@ -54,13 +54,15 @@ library WadRayMath {
    * @return The result of a*b, in wad
    **/
   function wadMul(uint256 a, uint256 b) internal pure returns (uint256) {
-    if (a == 0 || b == 0) {
-      return 0;
-    }
+    unchecked {
+      if (a == 0 || b == 0) {
+        return 0;
+      }
 
-    require(a <= (type(uint256).max - halfWAD) / b, Errors.MATH_MULTIPLICATION_OVERFLOW);
+      require(a <= (type(uint256).max - halfWAD) / b, Errors.MATH_MULTIPLICATION_OVERFLOW);
 
-    return (a * b + halfWAD) / WAD;
+      return (a * b + halfWAD) / WAD;
+    }
   }
 
   /**
@@ -70,12 +72,14 @@ library WadRayMath {
    * @return The result of a/b, in wad
    **/
   function wadDiv(uint256 a, uint256 b) internal pure returns (uint256) {
-    require(b != 0, Errors.MATH_DIVISION_BY_ZERO);
-    uint256 halfB = b / 2;
+    unchecked {
+      require(b != 0, Errors.MATH_DIVISION_BY_ZERO);
+      uint256 halfB = b / 2;
 
-    require(a <= (type(uint256).max - halfB) / WAD, Errors.MATH_MULTIPLICATION_OVERFLOW);
+      require(a <= (type(uint256).max - halfB) / WAD, Errors.MATH_MULTIPLICATION_OVERFLOW);
 
-    return (a * WAD + halfB) / b;
+      return (a * WAD + halfB) / b;
+    }
   }
 
   /**
@@ -85,13 +89,15 @@ library WadRayMath {
    * @return The result of a*b, in ray
    **/
   function rayMul(uint256 a, uint256 b) internal pure returns (uint256) {
-    if (a == 0 || b == 0) {
-      return 0;
-    }
+    unchecked {
+      if (a == 0 || b == 0) {
+        return 0;
+      }
 
-    require(a <= (type(uint256).max - halfRAY) / b, Errors.MATH_MULTIPLICATION_OVERFLOW);
+      require(a <= (type(uint256).max - halfRAY) / b, Errors.MATH_MULTIPLICATION_OVERFLOW);
 
-    return (a * b + halfRAY) / RAY;
+      return (a * b + halfRAY) / RAY;
+    }
   }
 
   /**
@@ -101,12 +107,14 @@ library WadRayMath {
    * @return The result of a/b, in ray
    **/
   function rayDiv(uint256 a, uint256 b) internal pure returns (uint256) {
-    require(b != 0, Errors.MATH_DIVISION_BY_ZERO);
-    uint256 halfB = b / 2;
+    unchecked {
+      require(b != 0, Errors.MATH_DIVISION_BY_ZERO);
+      uint256 halfB = b / 2;
 
-    require(a <= (type(uint256).max - halfB) / RAY, Errors.MATH_MULTIPLICATION_OVERFLOW);
+      require(a <= (type(uint256).max - halfB) / RAY, Errors.MATH_MULTIPLICATION_OVERFLOW);
 
-    return (a * RAY + halfB) / b;
+      return (a * RAY + halfB) / b;
+    }
   }
 
   /**
@@ -115,11 +123,13 @@ library WadRayMath {
    * @return a casted to wad, rounded half up to the nearest wad
    **/
   function rayToWad(uint256 a) internal pure returns (uint256) {
-    uint256 halfRatio = WAD_RAY_RATIO / 2;
-    uint256 result = halfRatio + a;
-    require(result >= halfRatio, Errors.MATH_ADDITION_OVERFLOW);
+    unchecked {
+      uint256 halfRatio = WAD_RAY_RATIO / 2;
+      uint256 result = halfRatio + a;
+      require(result >= halfRatio, Errors.MATH_ADDITION_OVERFLOW);
 
-    return result / WAD_RAY_RATIO;
+      return result / WAD_RAY_RATIO;
+    }
   }
 
   /**
@@ -128,8 +138,10 @@ library WadRayMath {
    * @return a converted in ray
    **/
   function wadToRay(uint256 a) internal pure returns (uint256) {
-    uint256 result = a * WAD_RAY_RATIO;
-    require(result / WAD_RAY_RATIO == a, Errors.MATH_MULTIPLICATION_OVERFLOW);
-    return result;
+    unchecked {
+      uint256 result = a * WAD_RAY_RATIO;
+      require(result / WAD_RAY_RATIO == a, Errors.MATH_MULTIPLICATION_OVERFLOW);
+      return result;
+    }
   }
 }
diff --git a/hardhat.config.ts b/hardhat.config.ts
@@ -67,7 +67,7 @@ let forkMode;
 
 const buidlerConfig: HardhatUserConfig = {
   gasReporter: {
-    enabled: false,
+    enabled: true,
   },
   contractSizer: {
     alphaSort: true,