Comments on the assembly mint loop (#403)

chiru-labs · Aug 7, 2022 · 002562b · 002562b
1 parent 3d7e5ee
commit 002562b
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/contracts/ERC721A.sol b/contracts/ERC721A.sol
@@ -763,6 +763,9 @@ contract ERC721A is IERC721A {
             uint256 end = startTokenId + quantity;
 
             // Use assembly to loop and emit the `Transfer` event for gas savings.
+            // The duplicated `log4` removes an extra check and reduces stack juggling.
+            // The assembly, together with the surrounding Solidity code, have been
+            // delicately arranged to nudge the compiler into producing optimized opcodes.
             assembly {
                 // Mask `to` to the lower 160 bits, in case the upper bits somehow aren't clean.
                 toMasked := and(to, _BITMASK_ADDRESS)