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Submission Details
Severity: gas

Gas1-ViaIrCompiling-CarlosAlegreUr

charlescheerful

📌 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.

🔍 Vulnerability Details

1ī¸âƒŖ 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:

(options...)
remappings = [...]
via_ir = true <-- Set flag for optimization

🚧 Note ⚠ī¸: Enabling via_ir makes the compilation process slower. Compilation-related tasks are expected to take quite a bit more of time when this flag is active.

📘 Information ℹī¸: The via_ir flag 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 _ir means in via_ir, Intermediate Representation..

📈 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 🧑‍đŸ”Ŧ

🚧 Notice ⚠ī¸: The optimization affects all the contract, so I've analyzed all the tests but invariant ones because forge snapshot does not provide gas consumtion metrics for those.

🚧 Notice ⚠ī¸: Negative numbers in the Gas Saved column 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%.

📘 Notice ℹī¸: 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 📸

Original

DSCEngineTest:testCanBurnDsc() (gas: 237295)
DSCEngineTest:testCanDepositCollateralWithoutMinting() (gas: 88270)
DSCEngineTest:testCanDepositedCollateralAndGetAccountInfo() (gas: 130228)
DSCEngineTest:testCanMintDsc() (gas: 204291)
DSCEngineTest:testCanMintWithDepositedCollateral() (gas: 203164)
DSCEngineTest:testCanRedeemCollateral() (gas: 127928)
DSCEngineTest:testCanRedeemDepositedCollateral() (gas: 251655)
DSCEngineTest:testCantBurnMoreThanUserHas() (gas: 13312)
DSCEngineTest:testCantLiquidateGoodHealthFactor() (gas: 354163)
DSCEngineTest:testGetAccountCollateralValue() (gas: 127827)
DSCEngineTest:testGetAccountCollateralValueFromInformation() (gas: 130226)
DSCEngineTest:testGetCollateralBalanceOfUser() (gas: 83444)
DSCEngineTest:testGetCollateralTokenPriceFeed() (gas: 12268)
DSCEngineTest:testGetCollateralTokens() (gas: 15603)
DSCEngineTest:testGetDsc() (gas: 7794)
DSCEngineTest:testGetLiquidationThreshold() (gas: 5616)
DSCEngineTest:testGetMinHealthFactor() (gas: 5547)
DSCEngineTest:testGetTimeout() (gas: 5532)
DSCEngineTest:testGetTokenAmountFromUsd() (gas: 26170)
DSCEngineTest:testGetUsdValue() (gas: 26254)
DSCEngineTest:testHealthFactorCanGoBelowOne() (gas: 290012)
DSCEngineTest:testLiquidationPayoutIsCorrect() (gas: 484401)
DSCEngineTest:testLiquidatorTakesOnUsersDebt() (gas: 483522)
DSCEngineTest:testMustImproveHealthFactorOnLiquidation() (gas: 2363648)
DSCEngineTest:testMustRedeemMoreThanZero() (gas: 236959)
DSCEngineTest:testPriceRevertsOnBadAnsweredInRound() (gas: 24369)
DSCEngineTest:testPriceRevertsOnStaleCheck() (gas: 21767)
DSCEngineTest:testProperlyReportsHealthFactor() (gas: 210229)
DSCEngineTest:testRevertsIfBurnAmountIsZero() (gas: 201181)
DSCEngineTest:testRevertsIfCollateralZero() (gas: 43623)
DSCEngineTest:testRevertsIfMintAmountBreaksHealthFactor() (gas: 166563)
DSCEngineTest:testRevertsIfMintAmountIsZero() (gas: 201106)
DSCEngineTest:testRevertsIfMintFails() (gas: 2032604)
DSCEngineTest:testRevertsIfMintedDscBreaksHealthFactor() (gas: 165932)
DSCEngineTest:testRevertsIfRedeemAmountIsZero() (gas: 201395)
DSCEngineTest:testRevertsIfTokenLengthDoesntMatchPriceFeeds() (gas: 180675)
DSCEngineTest:testRevertsIfTransferFails() (gas: 1930291)
DSCEngineTest:testRevertsIfTransferFromFails() (gas: 1955875)
DSCEngineTest:testRevertsWithUnapprovedCollateral() (gas: 707851)
DSCEngineTest:testUserHasNoMoreDebt() (gas: 483424)
DSCEngineTest:testUserStillHasSomeEthAfterLiquidation() (gas: 498431)
DecentralizedStablecoinTest:testCantBurnMoreThanYouHave() (gas: 59986)
DecentralizedStablecoinTest:testCantMintToZeroAddress() (gas: 12443)
DecentralizedStablecoinTest:testMustBurnMoreThanZero() (gas: 59972)
DecentralizedStablecoinTest:testMustMintMoreThanZero() (gas: 12062)

Optimized

DSCEngineTest:testCanBurnDsc() (gas: 234462)
DSCEngineTest:testCanDepositCollateralWithoutMinting() (gas: 89157)
DSCEngineTest:testCanDepositedCollateralAndGetAccountInfo() (gas: 128518)
DSCEngineTest:testCanMintDsc() (gas: 204032)
DSCEngineTest:testCanMintWithDepositedCollateral() (gas: 202684)
DSCEngineTest:testCanRedeemCollateral() (gas: 127418)
DSCEngineTest:testCanRedeemDepositedCollateral() (gas: 248461)
DSCEngineTest:testCantBurnMoreThanUserHas() (gas: 14399)
DSCEngineTest:testCantLiquidateGoodHealthFactor() (gas: 349925)
DSCEngineTest:testGetAccountCollateralValue() (gas: 126014)
DSCEngineTest:testGetAccountCollateralValueFromInformation() (gas: 128558)
DSCEngineTest:testGetCollateralBalanceOfUser() (gas: 83913)
DSCEngineTest:testGetCollateralTokenPriceFeed() (gas: 12251)
DSCEngineTest:testGetCollateralTokens() (gas: 16802)
DSCEngineTest:testGetDsc() (gas: 9041)
DSCEngineTest:testGetLiquidationThreshold() (gas: 5880)
DSCEngineTest:testGetMinHealthFactor() (gas: 6752)
DSCEngineTest:testGetTimeout() (gas: 5605)
DSCEngineTest:testGetTokenAmountFromUsd() (gas: 26493)
DSCEngineTest:testGetUsdValue() (gas: 26044)
DSCEngineTest:testHealthFactorCanGoBelowOne() (gas: 287373)
DSCEngineTest:testLiquidationPayoutIsCorrect() (gas: 476403)
DSCEngineTest:testLiquidatorTakesOnUsersDebt() (gas: 474882)
DSCEngineTest:testMustImproveHealthFactorOnLiquidation() (gas: 2364258)
DSCEngineTest:testMustRedeemMoreThanZero() (gas: 234352)
DSCEngineTest:testPriceRevertsOnBadAnsweredInRound() (gas: 24279)
DSCEngineTest:testPriceRevertsOnStaleCheck() (gas: 21836)
DSCEngineTest:testProperlyReportsHealthFactor() (gas: 207663)
DSCEngineTest:testRevertsIfBurnAmountIsZero() (gas: 200131)
DSCEngineTest:testRevertsIfCollateralZero() (gas: 44899)
DSCEngineTest:testRevertsIfMintAmountBreaksHealthFactor() (gas: 165142)
DSCEngineTest:testRevertsIfMintAmountIsZero() (gas: 199612)
DSCEngineTest:testRevertsIfMintFails() (gas: 2026539)
DSCEngineTest:testRevertsIfMintedDscBreaksHealthFactor() (gas: 163893)
DSCEngineTest:testRevertsIfRedeemAmountIsZero() (gas: 200261)
DSCEngineTest:testRevertsIfTokenLengthDoesntMatchPriceFeeds() (gas: 181848)
DSCEngineTest:testRevertsIfTransferFails() (gas: 1946641)
DSCEngineTest:testRevertsIfTransferFromFails() (gas: 1967717)
DSCEngineTest:testRevertsWithUnapprovedCollateral() (gas: 708487)
DSCEngineTest:testUserHasNoMoreDebt() (gas: 475044)
DSCEngineTest:testUserStillHasSomeEthAfterLiquidation() (gas: 488630)
DecentralizedStablecoinTest:testCantBurnMoreThanYouHave() (gas: 60278)
DecentralizedStablecoinTest:testCantMintToZeroAddress() (gas: 12893)
DecentralizedStablecoinTest:testMustBurnMoreThanZero() (gas: 60193)
DecentralizedStablecoinTest:testMustMintMoreThanZero() (gas: 12380)

🛠ī¸ Tools Used

  • Manual audit

  • Forge Snapshot

  • Bash scripts tailored to analyze forge snapshots.

📘 Notice ℹī¸: I've personally created the bash scripts. Here is a link to the github repo Forge-Snapshots-Analyzer.

đŸŽ¯ 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.

🚧 Notice ⚠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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