Slight for loop gas optimization

Use unchecked and pre-increment for for-loop iterators
redsh4de · Jan 31, 2023 · 3eef2fe · 3eef2fe
1 parent dd6eca7
commit 3eef2fe
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Showing 2 changed files with 11 additions and 6 deletions.
diff --git a/contracts/facets/DiamondLoupeFacet.sol b/contracts/facets/DiamondLoupeFacet.sol
@@ -28,10 +28,11 @@ contract DiamondLoupeFacet is IDiamondLoupe, IERC165 {
         LibDiamond.DiamondStorage storage ds = LibDiamond.diamondStorage();
         uint256 numFacets = ds.facetAddresses.length;
         facets_ = new Facet[](numFacets);
-        for (uint256 i; i < numFacets; i++) {
+        for (uint256 i; i < numFacets;) {
             address facetAddress_ = ds.facetAddresses[i];
             facets_[i].facetAddress = facetAddress_;
             facets_[i].functionSelectors = ds.facetFunctionSelectors[facetAddress_].functionSelectors;
+            unchecked { ++i; }
         }
     }
 

diff --git a/contracts/libraries/LibDiamond.sol b/contracts/libraries/LibDiamond.sol
@@ -72,7 +72,7 @@ library LibDiamond {
         address _init,
         bytes memory _calldata
     ) internal {
-        for (uint256 facetIndex; facetIndex < _diamondCut.length; facetIndex++) {
+        for (uint256 facetIndex; facetIndex < _diamondCut.length;) {
             IDiamondCut.FacetCutAction action = _diamondCut[facetIndex].action;
             if (action == IDiamondCut.FacetCutAction.Add) {
                 addFunctions(_diamondCut[facetIndex].facetAddress, _diamondCut[facetIndex].functionSelectors);
@@ -83,6 +83,7 @@ library LibDiamond {
             } else {
                 revert("LibDiamondCut: Incorrect FacetCutAction");
             }
+            unchecked { ++facetIndex; }
         }
         emit DiamondCut(_diamondCut, _init, _calldata);
         initializeDiamondCut(_init, _calldata);
@@ -102,7 +103,8 @@ library LibDiamond {
             address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
             require(oldFacetAddress == address(0), "LibDiamondCut: Can't add function that already exists");
             addFunction(ds, selector, selectorPosition, _facetAddress);
-            selectorPosition++;
+            ++selectorPosition;
+            unchecked { ++selectorIndex; }
         }
     }
 
@@ -115,13 +117,14 @@ library LibDiamond {
         if (selectorPosition == 0) {
             addFacet(ds, _facetAddress);
         }
-        for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
+        for (uint256 selectorIndex; selectorIndex < _functionSelectors.length;) {
             bytes4 selector = _functionSelectors[selectorIndex];
             address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
             require(oldFacetAddress != _facetAddress, "LibDiamondCut: Can't replace function with same function");
             removeFunction(ds, oldFacetAddress, selector);
             addFunction(ds, selector, selectorPosition, _facetAddress);
-            selectorPosition++;
+            ++selectorPosition;
+            unchecked { ++selectorIndex; }
         }
     }
 
@@ -130,10 +133,11 @@ library LibDiamond {
         DiamondStorage storage ds = diamondStorage();
         // if function does not exist then do nothing and return
         require(_facetAddress == address(0), "LibDiamondCut: Remove facet address must be address(0)");
-        for (uint256 selectorIndex; selectorIndex < _functionSelectors.length; selectorIndex++) {
+        for (uint256 selectorIndex; selectorIndex < _functionSelectors.length;) {
             bytes4 selector = _functionSelectors[selectorIndex];
             address oldFacetAddress = ds.selectorToFacetAndPosition[selector].facetAddress;
             removeFunction(ds, oldFacetAddress, selector);
+            unchecked { ++selectorIndex; }
         }
     }