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[ETCM-18] EIP-1108: Reduce alt_bn128 precompile gas costs #646

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Merged
merged 1 commit into from
Aug 27, 2020
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[ETCM-18] EIP-1108: Reduce alt_bn128 precompile gas costs #646

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31 changes: 30 additions & 1 deletion src/main/scala/io/iohk/ethereum/vm/BlockchainConfigForEvm.scala
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,8 @@ package io.iohk.ethereum.vm

import io.iohk.ethereum.domain.UInt256
import io.iohk.ethereum.utils.BlockchainConfig
import io.iohk.ethereum.vm.BlockchainConfigForEvm.EtcForks.{Agharta, Atlantis, BeforeAtlantis, EtcFork, Phoenix}
import io.iohk.ethereum.vm.BlockchainConfigForEvm.EthForks.{BeforeByzantium, Byzantium, Constantinople, Petersburg}

/**
* A subset of [[io.iohk.ethereum.utils.BlockchainConfig]] that is required for instantiating an [[EvmConfig]]
Expand All @@ -23,9 +25,36 @@ case class BlockchainConfigForEvm(
petersburgBlockNumber: BigInt,
phoenixBlockNumber: BigInt,
chainId: Byte
)
){
def etcForkForBlockNumber(blockNumber: BigInt): EtcFork = blockNumber match {
case _ if blockNumber < atlantisBlockNumber => BeforeAtlantis
case _ if blockNumber < aghartaBlockNumber => Atlantis
case _ if blockNumber < phoenixBlockNumber => Agharta
case _ if blockNumber >= phoenixBlockNumber => Phoenix
}

def ethForkForBlockNumber(blockNumber: BigInt): BlockchainConfigForEvm.EthForks.Value = blockNumber match {
case _ if blockNumber < byzantiumBlockNumber => BeforeByzantium
case _ if blockNumber < constantinopleBlockNumber => Byzantium
case _ if blockNumber < petersburgBlockNumber => Constantinople
case _ if blockNumber >= petersburgBlockNumber => Petersburg
// TODO add Istanbul
}
}

object BlockchainConfigForEvm {

object EtcForks extends Enumeration {
type EtcFork = Value
val BeforeAtlantis, Atlantis, Agharta, Phoenix = Value
}

object EthForks extends Enumeration {
type EthFork = Value
val BeforeByzantium, Byzantium, Constantinople, Petersburg, Istanbul = Value
}


def apply(blockchainConfig: BlockchainConfig): BlockchainConfigForEvm = {
import blockchainConfig._
BlockchainConfigForEvm(
Expand Down
3 changes: 2 additions & 1 deletion src/main/scala/io/iohk/ethereum/vm/OpCode.scala
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Expand Up @@ -4,6 +4,7 @@ import akka.util.ByteString
import io.iohk.ethereum.crypto.kec256
import io.iohk.ethereum.domain.{Account, Address, TxLogEntry, UInt256}
import io.iohk.ethereum.domain.UInt256._
import io.iohk.ethereum.vm.BlockchainConfigForEvm.EthForks

// scalastyle:off magic.number
// scalastyle:off number.of.types
Expand Down Expand Up @@ -664,7 +665,7 @@ case object SSTORE extends OpCode(0x55, 2, 0, _.G_zero) {

private def isEip1283Enabled[W <: WorldStateProxy[W, S], S <: Storage[S]](state: ProgramState[W, S]): Boolean = {
val blockNumber = state.env.blockHeader.number
blockNumber >= state.config.blockchainConfig.constantinopleBlockNumber && blockNumber < state.config.blockchainConfig.petersburgBlockNumber
state.config.blockchainConfig.ethForkForBlockNumber(blockNumber) == EthForks.Constantinople
}
}

Expand Down
54 changes: 35 additions & 19 deletions src/main/scala/io/iohk/ethereum/vm/PrecompiledContracts.scala
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Expand Up @@ -7,7 +7,9 @@ import io.iohk.ethereum.crypto.zksnark.{BN128Fp, PairingCheck}
import io.iohk.ethereum.crypto.zksnark.PairingCheck.G1G2Pair
import io.iohk.ethereum.domain.Address
import io.iohk.ethereum.utils.ByteUtils

import io.iohk.ethereum.vm.BlockchainConfigForEvm.EtcForks.EtcFork
import io.iohk.ethereum.vm.BlockchainConfigForEvm.EthForks.EthFork
import io.iohk.ethereum.vm.BlockchainConfigForEvm.{EtcForks, EthForks}
import scala.util.Try

// scalastyle:off magic.number
Expand All @@ -29,7 +31,7 @@ object PrecompiledContracts {
IdAddr -> Identity
)

val byzantiumContracts = contracts ++ Map(
val byzantiumAtlantisContracts = contracts ++ Map(
ModExpAddr -> ModExp,
Bn128AddAddr -> Bn128Add,
Bn128MulAddr -> Bn128Mul,
Expand All @@ -51,21 +53,25 @@ object PrecompiledContracts {

private def getContract(context: ProgramContext[_, _]): Option[PrecompiledContract] = {
context.recipientAddr.flatMap{ addr =>
if (context.blockHeader.number >= context.evmConfig.blockchainConfig.byzantiumBlockNumber ||
context.blockHeader.number >= context.evmConfig.blockchainConfig.atlantisBlockNumber) {
if (context.evmConfig.blockchainConfig.ethForkForBlockNumber(context.blockHeader.number) >= EthForks.Byzantium ||
context.evmConfig.blockchainConfig.etcForkForBlockNumber(context.blockHeader.number) >= EtcForks.Atlantis) {
// byzantium and atlantis hard fork introduce the same set of precompiled contracts
byzantiumContracts.get(addr)
byzantiumAtlantisContracts.get(addr)
} else
contracts.get(addr)
}
}

sealed trait PrecompiledContract {
protected def exec(inputData: ByteString): Option[ByteString]
protected def gas(inputData: ByteString): BigInt
protected def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt

def run[W <: WorldStateProxy[W, S], S <: Storage[S]](context: ProgramContext[W, S]): ProgramResult[W, S] = {
val g = gas(context.inputData)

val ethFork = context.evmConfig.blockchainConfig.ethForkForBlockNumber(context.blockHeader.number)
val etcFork = context.evmConfig.blockchainConfig.etcForkForBlockNumber(context.blockHeader.number)

val g = gas(context.inputData, etcFork, ethFork)

val (result, error, gasRemaining): (ByteString, Option[ProgramError], BigInt) =
if (g <= context.startGas)
Expand Down Expand Up @@ -108,8 +114,7 @@ object PrecompiledContracts {

}

def gas(inputData: ByteString): BigInt =
3000
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt = 3000

private def hasOnlyLastByteSet(v: ByteString): Boolean =
v.dropWhile(_ == 0).size == 1
Expand All @@ -119,23 +124,23 @@ object PrecompiledContracts {
def exec(inputData: ByteString): Option[ByteString] =
Some(sha256(inputData))

def gas(inputData: ByteString): BigInt =
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt =
60 + 12 * wordsForBytes(inputData.size)
}

object Ripemp160 extends PrecompiledContract {
def exec(inputData: ByteString): Option[ByteString] =
Some(ByteUtils.padLeft(ripemd160(inputData), 32))

def gas(inputData: ByteString): BigInt =
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt =
600 + 120 * wordsForBytes(inputData.size)
}

object Identity extends PrecompiledContract {
def exec(inputData: ByteString): Option[ByteString] =
Some(inputData)

def gas(inputData: ByteString): BigInt =
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt =
15 + 3 * wordsForBytes(inputData.size)
}

Expand Down Expand Up @@ -168,7 +173,7 @@ object PrecompiledContracts {
Some(ByteString(ByteUtils.bigIntegerToBytes(result.bigInteger, modLength)))
}

def gas(inputData: ByteString): BigInt = {
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt = {
val baseLength = getLength(inputData, 0)
val expLength = getLength(inputData, 1)
val modLength = getLength(inputData, 2)
Expand Down Expand Up @@ -256,8 +261,11 @@ object PrecompiledContracts {
}


def gas(inputData: ByteString): BigInt =
BigInt(500)
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt =
if(etcFork >= EtcForks.Phoenix || ethFork >= EthForks.Istanbul)
BigInt(150) // https://eips.ethereum.org/EIPS/eip-1108
else
BigInt(500)


private def getCurvePointsBytes(input: ByteString): (ByteString, ByteString, ByteString, ByteString) = {
Expand Down Expand Up @@ -293,8 +301,11 @@ object PrecompiledContracts {
}
}

def gas(inputData: ByteString): BigInt =
40000
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt =
if(etcFork >= EtcForks.Phoenix || ethFork >= EthForks.Istanbul)
6000 // https://eips.ethereum.org/EIPS/eip-1108
else
40000

private def getCurvePointsBytes(input: ByteString): (ByteString, ByteString, ByteString) = {
(input.slice(0, 32),
Expand Down Expand Up @@ -325,8 +336,13 @@ object PrecompiledContracts {
}
}

def gas(inputData: ByteString): BigInt = {
80000 * (inputData.length / inputLength) + 100000
def gas(inputData: ByteString, etcFork: EtcFork, ethFork: EthFork): BigInt = {
val k = inputData.length / inputLength
if(etcFork >= EtcForks.Phoenix || ethFork >= EthForks.Istanbul){ // https://eips.ethereum.org/EIPS/eip-1108
34000 * k + 45000
} else {
80000 * k + 100000
}
}

// Method which stops reading another points if one of earlier ones failed (had invalid coordinates, or was not on
Expand Down