Gas1-ViaIrCompiling-CarlosAlegreUr
đ Summary
After this optimization, client-tests still pass, with gas savings of 0.217%. Because of being a compiling process optimization, it has been applied to all contracts in scope.
đ Vulnerability Details
1ī¸âŖ Use via_ir = true for an Enhanced Compiler Process
The via_ir flag in the foundry.toml file triggers a more optimized compiler. This change resulted in a 0.217% improvement over the unoptimized contract.
foundry.toml Configuration:
đ§ Note â ī¸: Enabling
via_irmakes the compilation process slower. Compilation-related tasks are expected to take quite a bit more of time when this flag is active.
đ Information âšī¸: The
via_irflag instructs Foundry to utilize Intermediate Representation (IR). IR is a low-level language bridging high-level source code and machine code. This intermediate step allows for additional optimization techniques. That's what the_irmeans invia_ir, Intermediate Representation..
đ Impact
Metrics derived from gas consumption of the provided tests:
| Optimization Method | Optimized Gas | Original Gas | Gas Saved | % Saved |
|---|---|---|---|---|
| Use of via_ir | 15,039,663 | 15,072,846 | 33,183 | 0.217% |
Metrics were taken by running the forge snapshot command and compared with bash scripts tailored to analyze the results of forge snapshots.
Test by test breakdown đ§âđŦ
đ§ Notice â ī¸: The optimization affects all the contract, so I've analyzed all the tests but invariant ones because
forge snapshotdoes not provide gas consumtion metrics for those.
đ§ Notice â ī¸: Negative numbers in the
Gas Savedcolumn means the "optimization" increased the consumption of gas in that test. But the overall outcome in this case is positive so it can be considered an optimization.
| Test Name | Optimized Gas | Original Gas | Gas Saved |
|---|---|---|---|
| DSCEngineTest:testCanMintWithDepositedCollateral | 202,684 | 203,164 | 480 |
| DSCEngineTest:testHealthFactorCanGoBelowOne | 287,373 | 290,012 | 2,639 |
| DSCEngineTest:testGetCollateralBalanceOfUser | 83,913 | 83,444 | -469 |
| DSCEngineTest:testGetUsdValue | 26,044 | 26,254 | 210 |
| DSCEngineTest:testGetAccountCollateralValue | 126,014 | 127,827 | 1,813 |
| DSCEngineTest:testRevertsWithUnapprovedCollateral | 708,487 | 707,851 | -636 |
| DSCEngineTest:testLiquidatorTakesOnUsersDebt | 474,882 | 483,522 | 8,640 |
| DSCEngineTest:testUserStillHasSomeEthAfterLiquidation | 488,630 | 498,431 | 9,801 |
| DSCEngineTest:testCantLiquidateGoodHealthFactor | 349,925 | 354,163 | 4,238 |
| DSCEngineTest:testMustRedeemMoreThanZero | 234,352 | 236,959 | 2,607 |
| DSCEngineTest:testRevertsIfTransferFails | 1,946,641 | 1,930,291 | -16,350 |
| DSCEngineTest:testCantBurnMoreThanUserHas | 14,399 | 13,312 | -1,087 |
| DSCEngineTest:testRevertsIfTokenLengthDoesntMatchPriceFeeds | 181,848 | 180,675 | -1,173 |
| DSCEngineTest:testMustImproveHealthFactorOnLiquidation | 2,364,258 | 2,363,648 | -610 |
| DSCEngineTest:testGetLiquidationThreshold | 5,880 | 5,616 | -264 |
| DSCEngineTest:testGetCollateralTokenPriceFeed | 12,251 | 12,268 | 17 |
| DSCEngineTest:testCanRedeemDepositedCollateral | 248,461 | 251,655 | 3,194 |
| DSCEngineTest:testRevertsIfMintAmountIsZero | 199,612 | 201,106 | 1,494 |
| DSCEngineTest:testUserHasNoMoreDebt | 475,044 | 483,424 | 8,380 |
| DSCEngineTest:testCanRedeemCollateral | 127,418 | 127,928 | 510 |
| DSCEngineTest:testProperlyReportsHealthFactor | 207,663 | 210,229 | 2,566 |
| DSCEngineTest:testGetTokenAmountFromUsd | 26,493 | 26,170 | -323 |
| DSCEngineTest:testCanDepositedCollateralAndGetAccountInfo | 128,518 | 130,228 | 1,710 |
| DSCEngineTest:testRevertsIfTransferFromFails | 1,967,717 | 1,955,875 | -11,842 |
| DecentralizedStablecoinTest:testCantMintToZeroAddress | 12,893 | 12,443 | -450 |
| DSCEngineTest:testPriceRevertsOnStaleCheck | 21,836 | 21,767 | -69 |
| DSCEngineTest:testGetDsc | 9,041 | 7,794 | -1,247 |
| DSCEngineTest:testCanBurnDsc | 234,462 | 237,295 | 2,833 |
| DSCEngineTest:testCanMintDsc | 204,032 | 204,291 | 259 |
| DSCEngineTest:testPriceRevertsOnBadAnsweredInRound | 24,279 | 24,369 | 90 |
| DSCEngineTest:testRevertsIfMintedDscBreaksHealthFactor | 163,893 | 165,932 | 2,039 |
| DSCEngineTest:testRevertsIfMintFails | 2,026,539 | 2,032,604 | 6,065 |
| DSCEngineTest:testRevertsIfBurnAmountIsZero | 200,131 | 201,181 | 1,050 |
| DecentralizedStablecoinTest:testMustBurnMoreThanZero | 60,193 | 59,972 | -221 |
| DecentralizedStablecoinTest:testMustMintMoreThanZero | 12,380 | 12,062 | -318 |
| DSCEngineTest:testGetMinHealthFactor | 6,752 | 5,547 | -1,205 |
| DecentralizedStablecoinTest:testCantBurnMoreThanYouHave | 60,278 | 59,986 | -292 |
| DSCEngineTest:testRevertsIfCollateralZero | 44,899 | 43,623 | -1,276 |
| DSCEngineTest:testCanDepositCollateralWithoutMinting | 89,157 | 88,270 | -887 |
| DSCEngineTest:testLiquidationPayoutIsCorrect | 476,403 | 484,401 | 7,998 |
| DSCEngineTest:testGetAccountCollateralValueFromInformation | 128,558 | 130,226 | 1,668 |
| DSCEngineTest:testGetTimeout | 5,605 | 5,532 | -73 |
| DSCEngineTest:testGetCollateralTokens | 16,802 | 15,603 | -1,199 |
| TOTAL | 15,052,043 | 15,084,908 | 32,865 |
Total saved percentage => 0.217%.
đ Notice âšī¸: The percentage has been calculated with these numbers from the TOTAL:
( 32,865 / 15,084,908) * 100
They mean:
(totalGasSaved / originalGasCost) * 100
Forge Snapshots Used đ¸
Original
Optimized
đ ī¸ Tools Used
Manual audit
Forge Snapshot
Bash scripts tailored to analyze forge snapshots.
đ Notice âšī¸: I've personally created the bash scripts. Here is a link to the github repo Forge-Snapshots-Analyzer.
đ¯ Recommendations
Implementing this gas optimization is recommended. This benefits both end-users and the protocol in terms of cost, while ensuring protocol security remains uncompromised as tests are passing.
đ§ Notice â ī¸: If a significant vulnerability necessitating major code changes arises, this gas optimization technique remains relevant and applicable. Nonetheless some gas analysis as the one used here is always needed to make sure it's actually saving gas.
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