⚡️ Optimise _mul_div Method in ERC4626 Contract (#162)

Signed-off-by: Pascal Marco Caversaccio <pascal.caversaccio@hotmail.ch>

CHANGELOG.md

@@ -10,7 +10,9 @@
 ### ♻️ Refactoring
 
 - **Extensions**
-  - [`ERC4626`](https://github.com/pcaversaccio/snekmate/blob/v0.0.3/src/extensions/ERC4626.vy): Remove the non-standard `increase_allowance` and `decrease_allowance` functions. ([#160](https://github.com/pcaversaccio/snekmate/pull/160))
+  - [`ERC4626`](https://github.com/pcaversaccio/snekmate/blob/v0.0.3/src/extensions/ERC4626.vy):
+    - Remove the non-standard `increase_allowance` and `decrease_allowance` functions. ([#160](https://github.com/pcaversaccio/snekmate/pull/160))
+    - Optimise the method used to factor powers of two out of the denominator in `_mul_div`. ([#162](https://github.com/pcaversaccio/snekmate/pull/162))
 - **Tokens**
   - [`ERC20`](https://github.com/pcaversaccio/snekmate/blob/v0.0.3/src/tokens/ERC20.vy):
     - Optimise the `set_minter` function to save one `SLOAD`. ([#154](https://github.com/pcaversaccio/snekmate/pull/154))

package.json

@@ -37,7 +37,7 @@
   ],
   "devDependencies": {
     "@openzeppelin/merkle-tree": "^1.0.5",
-    "eslint": "^8.49.0",
+    "eslint": "^8.50.0",
     "eslint-config-prettier": "^9.0.0",
     "ethers": "^6.7.1",
     "keccak256": "^1.0.6",

src/extensions/ERC4626.vy

@@ -1119,10 +1119,7 @@ def _mul_div(x: uint256, y: uint256, denominator: uint256, roundup: bool) -> uin
     # unless the denominator is zero (which is prevented above),
     # in which case `twos` is zero. For more details, please refer to:
     # https://cs.stackexchange.com/q/138556.
-
-    # The following line does not overflow because the denominator
-    # cannot be zero at this stage of the function.
-    twos: uint256 = denominator & (unsafe_add(~denominator, 1))
+    twos: uint256 = unsafe_sub(0, denominator) & denominator
     # Divide denominator by `twos`.
     denominator_div: uint256 = unsafe_div(denominator, twos)
     # Divide "[prod1 prod0]" by `twos`.

yarn.lock

@@ -61,10 +61,10 @@
     minimatch "^3.1.2"
     strip-json-comments "^3.1.1"
 
-"@eslint/js@8.49.0":
-  version "8.49.0"
-  resolved "https://registry.yarnpkg.com/@eslint/js/-/js-8.49.0.tgz#86f79756004a97fa4df866835093f1df3d03c333"
-  integrity sha512-1S8uAY/MTJqVx0SC4epBq+N2yhuwtNwLbJYNZyhL2pO1ZVKn5HFXav5T41Ryzy9K9V7ZId2JB2oy/W4aCd9/2w==
+"@eslint/js@8.50.0":
+  version "8.50.0"
+  resolved "https://registry.yarnpkg.com/@eslint/js/-/js-8.50.0.tgz#9e93b850f0f3fa35f5fa59adfd03adae8488e484"
+  integrity sha512-NCC3zz2+nvYd+Ckfh87rA47zfu2QsQpvc6k1yzTk+b9KzRj0wkGa8LSoGOXN6Zv4lRf/EIoZ80biDh9HOI+RNQ==
 
 "@ethereumjs/rlp@^4.0.1":
   version "4.0.1"
@@ -682,15 +682,15 @@ eslint-visitor-keys@^3.3.0, eslint-visitor-keys@^3.4.1, eslint-visitor-keys@^3.4
   resolved "https://registry.yarnpkg.com/eslint-visitor-keys/-/eslint-visitor-keys-3.4.3.tgz#0cd72fe8550e3c2eae156a96a4dddcd1c8ac5800"
   integrity sha512-wpc+LXeiyiisxPlEkUzU6svyS1frIO3Mgxj1fdy7Pm8Ygzguax2N3Fa/D/ag1WqbOprdI+uY6wMUl8/a2G+iag==
 
-eslint@^8.49.0:
-  version "8.49.0"
-  resolved "https://registry.yarnpkg.com/eslint/-/eslint-8.49.0.tgz#09d80a89bdb4edee2efcf6964623af1054bf6d42"
-  integrity sha512-jw03ENfm6VJI0jA9U+8H5zfl5b+FvuU3YYvZRdZHOlU2ggJkxrlkJH4HcDrZpj6YwD8kuYqvQM8LyesoazrSOQ==
+eslint@^8.50.0:
+  version "8.50.0"
+  resolved "https://registry.yarnpkg.com/eslint/-/eslint-8.50.0.tgz#2ae6015fee0240fcd3f83e1e25df0287f487d6b2"
+  integrity sha512-FOnOGSuFuFLv/Sa+FDVRZl4GGVAAFFi8LecRsI5a1tMO5HIE8nCm4ivAlzt4dT3ol/PaaGC0rJEEXQmHJBGoOg==
   dependencies:
     "@eslint-community/eslint-utils" "^4.2.0"
     "@eslint-community/regexpp" "^4.6.1"
     "@eslint/eslintrc" "^2.1.2"
-    "@eslint/js" "8.49.0"
+    "@eslint/js" "8.50.0"
     "@humanwhocodes/config-array" "^0.11.11"
     "@humanwhocodes/module-importer" "^1.0.1"
     "@nodelib/fs.walk" "^1.2.8"