Optimise output hash (openintentsframework#32)

Author: reednaa

src/input/types/MandateOutputType.sol

@@ -55,11 +55,14 @@ library MandateOutputType {
  ) internal pure returns (bytes32) {
  unchecked {
  bytes memory currentHash = new bytes(32 * outputs.length);
-
+ uint256 p;
+ assembly ("memory-safe") {
+ p := add(currentHash, 0x20)
+ }
  for (uint256 i = 0; i < outputs.length; ++i) {
  bytes32 outputHash = hashOutput(outputs[i]);
  assembly ("memory-safe") {
- mstore(add(add(currentHash, 0x20), mul(i, 0x20)), outputHash)
+ mstore(add(p, mul(i, 0x20)), outputHash)
  }
  }
  return keccak256(currentHash);
@@ -90,11 +93,14 @@ library MandateOutputType {
  ) internal pure returns (bytes32) {
  unchecked {
  bytes memory currentHash = new bytes(32 * outputs.length);
-
+ uint256 p;
+ assembly ("memory-safe") {
+ p := add(currentHash, 0x20)
+ }
  for (uint256 i = 0; i < outputs.length; ++i) {
  bytes32 outputHash = hashOutputM(outputs[i]);
  assembly ("memory-safe") {
- mstore(add(add(currentHash, 0x20), mul(i, 0x20)), outputHash)
+ mstore(add(p, mul(i, 0x20)), outputHash)
  }
  }
  return keccak256(currentHash);