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params, core/vm: Istanbul EIP-1108 bn256 gas cost reduction (ethereum…
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…#19904)

* params: add IsIstanbul to config + rules

IstanbulBlock, used to determine if the config IsIstanbul, is currently
left nil until an actual block is chosen.

* params, core/vm: implement EIP-1108

Old gas costs for elliptic curve operations are given the PreIstanbul
prefix, while current gas costs retain the unprefixed names. The actual
precompile implementations are the same, so they are factored out into
common functions that are called by the pre-Istanbul and current
precompile structs. Finally, an Istanbul precompile list is added that
references the new precompile structs, which in turn reference the new
gas costs.

* params: fix fork ordering, add missing chain compatibility check
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@Shadowfiend @karalabe
Shadowfiend authored and karalabe committed Aug 6, 2019
1 parent aa6005b commit beff5fa
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Showing 4 changed files with 144 additions and 45 deletions.
125 changes: 99 additions & 26 deletions core/vm/contracts.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -54,9 +54,22 @@ var PrecompiledContractsByzantium = map[common.Address]PrecompiledContract{
common.BytesToAddress([]byte{3}): &ripemd160hash{},
common.BytesToAddress([]byte{4}): &dataCopy{},
common.BytesToAddress([]byte{5}): &bigModExp{},
common.BytesToAddress([]byte{6}): &bn256Add{},
common.BytesToAddress([]byte{7}): &bn256ScalarMul{},
common.BytesToAddress([]byte{8}): &bn256Pairing{},
common.BytesToAddress([]byte{6}): &bn256AddByzantium{},
common.BytesToAddress([]byte{7}): &bn256ScalarMulByzantium{},
common.BytesToAddress([]byte{8}): &bn256PairingByzantium{},
}

// PrecompiledContractsIstanbul contains the default set of pre-compiled Ethereum
// contracts used in the Istanbul release.
var PrecompiledContractsIstanbul = map[common.Address]PrecompiledContract{
common.BytesToAddress([]byte{1}): &ecrecover{},
common.BytesToAddress([]byte{2}): &sha256hash{},
common.BytesToAddress([]byte{3}): &ripemd160hash{},
common.BytesToAddress([]byte{4}): &dataCopy{},
common.BytesToAddress([]byte{5}): &bigModExp{},
common.BytesToAddress([]byte{6}): &bn256AddIstanbul{},
common.BytesToAddress([]byte{7}): &bn256ScalarMulIstanbul{},
common.BytesToAddress([]byte{8}): &bn256PairingIstanbul{},
}

// RunPrecompiledContract runs and evaluates the output of a precompiled contract.
Expand Down Expand Up @@ -271,15 +284,9 @@ func newTwistPoint(blob []byte) (*bn256.G2, error) {
return p, nil
}

// bn256Add implements a native elliptic curve point addition.
type bn256Add struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256Add) RequiredGas(input []byte) uint64 {
return params.Bn256AddGas
}

func (c *bn256Add) Run(input []byte) ([]byte, error) {
// runBn256Add implements the Bn256Add precompile, referenced by both
// Byzantium and Istanbul operations.
func runBn256Add(input []byte) ([]byte, error) {
x, err := newCurvePoint(getData(input, 0, 64))
if err != nil {
return nil, err
Expand All @@ -293,15 +300,35 @@ func (c *bn256Add) Run(input []byte) ([]byte, error) {
return res.Marshal(), nil
}

// bn256ScalarMul implements a native elliptic curve scalar multiplication.
type bn256ScalarMul struct{}
// bn256Add implements a native elliptic curve point addition conforming to
// Istanbul consensus rules.
type bn256AddIstanbul struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256AddIstanbul) RequiredGas(input []byte) uint64 {
return params.Bn256AddGasIstanbul
}

func (c *bn256AddIstanbul) Run(input []byte) ([]byte, error) {
return runBn256Add(input)
}

// bn256AddByzantium implements a native elliptic curve point addition
// conforming to Byzantium consensus rules.
type bn256AddByzantium struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256ScalarMul) RequiredGas(input []byte) uint64 {
return params.Bn256ScalarMulGas
func (c *bn256AddByzantium) RequiredGas(input []byte) uint64 {
return params.Bn256AddGasByzantium
}

func (c *bn256AddByzantium) Run(input []byte) ([]byte, error) {
return runBn256Add(input)
}

func (c *bn256ScalarMul) Run(input []byte) ([]byte, error) {
// runBn256ScalarMul implements the Bn256ScalarMul precompile, referenced by
// both Byzantium and Istanbul operations.
func runBn256ScalarMul(input []byte) ([]byte, error) {
p, err := newCurvePoint(getData(input, 0, 64))
if err != nil {
return nil, err
Expand All @@ -311,6 +338,32 @@ func (c *bn256ScalarMul) Run(input []byte) ([]byte, error) {
return res.Marshal(), nil
}

// bn256ScalarMulIstanbul implements a native elliptic curve scalar
// multiplication conforming to Istanbul consensus rules.
type bn256ScalarMulIstanbul struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256ScalarMulIstanbul) RequiredGas(input []byte) uint64 {
return params.Bn256ScalarMulGasIstanbul
}

func (c *bn256ScalarMulIstanbul) Run(input []byte) ([]byte, error) {
return runBn256ScalarMul(input)
}

// bn256ScalarMulByzantium implements a native elliptic curve scalar
// multiplication conforming to Byzantium consensus rules.
type bn256ScalarMulByzantium struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256ScalarMulByzantium) RequiredGas(input []byte) uint64 {
return params.Bn256ScalarMulGasByzantium
}

func (c *bn256ScalarMulByzantium) Run(input []byte) ([]byte, error) {
return runBn256ScalarMul(input)
}

var (
// true32Byte is returned if the bn256 pairing check succeeds.
true32Byte = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1}
Expand All @@ -322,15 +375,9 @@ var (
errBadPairingInput = errors.New("bad elliptic curve pairing size")
)

// bn256Pairing implements a pairing pre-compile for the bn256 curve
type bn256Pairing struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256Pairing) RequiredGas(input []byte) uint64 {
return params.Bn256PairingBaseGas + uint64(len(input)/192)*params.Bn256PairingPerPointGas
}

func (c *bn256Pairing) Run(input []byte) ([]byte, error) {
// runBn256Pairing implements the Bn256Pairing precompile, referenced by both
// Byzantium and Istanbul operations.
func runBn256Pairing(input []byte) ([]byte, error) {
// Handle some corner cases cheaply
if len(input)%192 > 0 {
return nil, errBadPairingInput
Expand Down Expand Up @@ -358,3 +405,29 @@ func (c *bn256Pairing) Run(input []byte) ([]byte, error) {
}
return false32Byte, nil
}

// bn256PairingIstanbul implements a pairing pre-compile for the bn256 curve
// conforming to Istanbul consensus rules.
type bn256PairingIstanbul struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256PairingIstanbul) RequiredGas(input []byte) uint64 {
return params.Bn256PairingBaseGasIstanbul + uint64(len(input)/192)*params.Bn256PairingPerPointGasIstanbul
}

func (c *bn256PairingIstanbul) Run(input []byte) ([]byte, error) {
return runBn256Pairing(input)
}

// bn256PairingByzantium implements a pairing pre-compile for the bn256 curve
// conforming to Byzantium consensus rules.
type bn256PairingByzantium struct{}

// RequiredGas returns the gas required to execute the pre-compiled contract.
func (c *bn256PairingByzantium) RequiredGas(input []byte) uint64 {
return params.Bn256PairingBaseGasByzantium + uint64(len(input)/192)*params.Bn256PairingPerPointGasByzantium
}

func (c *bn256PairingByzantium) Run(input []byte) ([]byte, error) {
return runBn256Pairing(input)
}
6 changes: 6 additions & 0 deletions core/vm/evm.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,9 @@ func run(evm *EVM, contract *Contract, input []byte, readOnly bool) ([]byte, err
if evm.chainRules.IsByzantium {
precompiles = PrecompiledContractsByzantium
}
if evm.chainRules.IsIstanbul {
precompiles = PrecompiledContractsIstanbul
}
if p := precompiles[*contract.CodeAddr]; p != nil {
return RunPrecompiledContract(p, input, contract)
}
Expand Down Expand Up @@ -206,6 +209,9 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
if evm.chainRules.IsByzantium {
precompiles = PrecompiledContractsByzantium
}
if evm.chainRules.IsIstanbul {
precompiles = PrecompiledContractsIstanbul
}
if precompiles[addr] == nil && evm.chainRules.IsEIP158 && value.Sign() == 0 {
// Calling a non existing account, don't do anything, but ping the tracer
if evm.vmConfig.Debug && evm.depth == 0 {
Expand Down
29 changes: 22 additions & 7 deletions params/config.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,7 @@ var (
ByzantiumBlock: big.NewInt(4370000),
ConstantinopleBlock: big.NewInt(7280000),
PetersburgBlock: big.NewInt(7280000),
IstanbulBlock: nil,
Ethash: new(EthashConfig),
}

Expand Down Expand Up @@ -102,6 +103,7 @@ var (
ByzantiumBlock: big.NewInt(1700000),
ConstantinopleBlock: big.NewInt(4230000),
PetersburgBlock: big.NewInt(4939394),
IstanbulBlock: nil,
Ethash: new(EthashConfig),
}

Expand Down Expand Up @@ -139,6 +141,7 @@ var (
ByzantiumBlock: big.NewInt(1035301),
ConstantinopleBlock: big.NewInt(3660663),
PetersburgBlock: big.NewInt(4321234),
IstanbulBlock: nil,
Clique: &CliqueConfig{
Period: 15,
Epoch: 30000,
Expand Down Expand Up @@ -177,6 +180,7 @@ var (
ByzantiumBlock: big.NewInt(0),
ConstantinopleBlock: big.NewInt(0),
PetersburgBlock: big.NewInt(0),
IstanbulBlock: nil,
Clique: &CliqueConfig{
Period: 15,
Epoch: 30000,
Expand Down Expand Up @@ -209,16 +213,16 @@ var (
//
// This configuration is intentionally not using keyed fields to force anyone
// adding flags to the config to also have to set these fields.
AllEthashProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, new(EthashConfig), nil}
AllEthashProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, nil, new(EthashConfig), nil}

// AllCliqueProtocolChanges contains every protocol change (EIPs) introduced
// and accepted by the Ethereum core developers into the Clique consensus.
//
// This configuration is intentionally not using keyed fields to force anyone
// adding flags to the config to also have to set these fields.
AllCliqueProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, nil, &CliqueConfig{Period: 0, Epoch: 30000}}
AllCliqueProtocolChanges = &ChainConfig{big.NewInt(1337), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, nil, nil, &CliqueConfig{Period: 0, Epoch: 30000}}

TestChainConfig = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, new(EthashConfig), nil}
TestChainConfig = &ChainConfig{big.NewInt(1), big.NewInt(0), nil, false, big.NewInt(0), common.Hash{}, big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), big.NewInt(0), nil, nil, new(EthashConfig), nil}
TestRules = TestChainConfig.Rules(new(big.Int))
)

Expand Down Expand Up @@ -287,6 +291,7 @@ type ChainConfig struct {
ByzantiumBlock *big.Int `json:"byzantiumBlock,omitempty"` // Byzantium switch block (nil = no fork, 0 = already on byzantium)
ConstantinopleBlock *big.Int `json:"constantinopleBlock,omitempty"` // Constantinople switch block (nil = no fork, 0 = already activated)
PetersburgBlock *big.Int `json:"petersburgBlock,omitempty"` // Petersburg switch block (nil = same as Constantinople)
IstanbulBlock *big.Int `json:"istanbulBlock,omitempty"` // Istanbul switch block (nil = no fork, 0 = already on istanbul)
EWASMBlock *big.Int `json:"ewasmBlock,omitempty"` // EWASM switch block (nil = no fork, 0 = already activated)

// Various consensus engines
Expand Down Expand Up @@ -324,7 +329,7 @@ func (c *ChainConfig) String() string {
default:
engine = "unknown"
}
return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Byzantium: %v Constantinople: %v Petersburg: %v Engine: %v}",
return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Byzantium: %v Constantinople: %v Petersburg: %v Istanbul: %v Engine: %v}",
c.ChainID,
c.HomesteadBlock,
c.DAOForkBlock,
Expand All @@ -335,6 +340,7 @@ func (c *ChainConfig) String() string {
c.ByzantiumBlock,
c.ConstantinopleBlock,
c.PetersburgBlock,
c.IstanbulBlock,
engine,
)
}
Expand Down Expand Up @@ -381,6 +387,11 @@ func (c *ChainConfig) IsPetersburg(num *big.Int) bool {
return isForked(c.PetersburgBlock, num) || c.PetersburgBlock == nil && isForked(c.ConstantinopleBlock, num)
}

// IsIstanbul returns whether num is either equal to the Istanbul fork block or greater.
func (c *ChainConfig) IsIstanbul(num *big.Int) bool {
return isForked(c.IstanbulBlock, num)
}

// IsEWASM returns whether num represents a block number after the EWASM fork
func (c *ChainConfig) IsEWASM(num *big.Int) bool {
return isForked(c.EWASMBlock, num)
Expand Down Expand Up @@ -435,6 +446,9 @@ func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, head *big.Int) *Confi
if isForkIncompatible(c.PetersburgBlock, newcfg.PetersburgBlock, head) {
return newCompatError("Petersburg fork block", c.PetersburgBlock, newcfg.PetersburgBlock)
}
if isForkIncompatible(c.IstanbulBlock, newcfg.IstanbulBlock, head) {
return newCompatError("Istanbul fork block", c.IstanbulBlock, newcfg.IstanbulBlock)
}
if isForkIncompatible(c.EWASMBlock, newcfg.EWASMBlock, head) {
return newCompatError("ewasm fork block", c.EWASMBlock, newcfg.EWASMBlock)
}
Expand Down Expand Up @@ -502,9 +516,9 @@ func (err *ConfigCompatError) Error() string {
// Rules is a one time interface meaning that it shouldn't be used in between transition
// phases.
type Rules struct {
ChainID *big.Int
IsHomestead, IsEIP150, IsEIP155, IsEIP158 bool
IsByzantium, IsConstantinople, IsPetersburg bool
ChainID *big.Int
IsHomestead, IsEIP150, IsEIP155, IsEIP158 bool
IsByzantium, IsConstantinople, IsPetersburg, IsIstanbul bool
}

// Rules ensures c's ChainID is not nil.
Expand All @@ -522,5 +536,6 @@ func (c *ChainConfig) Rules(num *big.Int) Rules {
IsByzantium: c.IsByzantium(num),
IsConstantinople: c.IsConstantinople(num),
IsPetersburg: c.IsPetersburg(num),
IsIstanbul: c.IsIstanbul(num),
}
}
29 changes: 17 additions & 12 deletions params/protocol_params.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -99,18 +99,23 @@ const (

// Precompiled contract gas prices

EcrecoverGas uint64 = 3000 // Elliptic curve sender recovery gas price
Sha256BaseGas uint64 = 60 // Base price for a SHA256 operation
Sha256PerWordGas uint64 = 12 // Per-word price for a SHA256 operation
Ripemd160BaseGas uint64 = 600 // Base price for a RIPEMD160 operation
Ripemd160PerWordGas uint64 = 120 // Per-word price for a RIPEMD160 operation
IdentityBaseGas uint64 = 15 // Base price for a data copy operation
IdentityPerWordGas uint64 = 3 // Per-work price for a data copy operation
ModExpQuadCoeffDiv uint64 = 20 // Divisor for the quadratic particle of the big int modular exponentiation
Bn256AddGas uint64 = 500 // Gas needed for an elliptic curve addition
Bn256ScalarMulGas uint64 = 40000 // Gas needed for an elliptic curve scalar multiplication
Bn256PairingBaseGas uint64 = 100000 // Base price for an elliptic curve pairing check
Bn256PairingPerPointGas uint64 = 80000 // Per-point price for an elliptic curve pairing check
EcrecoverGas uint64 = 3000 // Elliptic curve sender recovery gas price
Sha256BaseGas uint64 = 60 // Base price for a SHA256 operation
Sha256PerWordGas uint64 = 12 // Per-word price for a SHA256 operation
Ripemd160BaseGas uint64 = 600 // Base price for a RIPEMD160 operation
Ripemd160PerWordGas uint64 = 120 // Per-word price for a RIPEMD160 operation
IdentityBaseGas uint64 = 15 // Base price for a data copy operation
IdentityPerWordGas uint64 = 3 // Per-work price for a data copy operation
ModExpQuadCoeffDiv uint64 = 20 // Divisor for the quadratic particle of the big int modular exponentiation

Bn256AddGasByzantium uint64 = 500 // Byzantium gas needed for an elliptic curve addition
Bn256AddGasIstanbul uint64 = 150 // Gas needed for an elliptic curve addition
Bn256ScalarMulGasByzantium uint64 = 40000 // Byzantium gas needed for an elliptic curve scalar multiplication
Bn256ScalarMulGasIstanbul uint64 = 6000 // Gas needed for an elliptic curve scalar multiplication
Bn256PairingBaseGasByzantium uint64 = 100000 // Byzantium base price for an elliptic curve pairing check
Bn256PairingBaseGasIstanbul uint64 = 45000 // Base price for an elliptic curve pairing check
Bn256PairingPerPointGasByzantium uint64 = 80000 // Byzantium per-point price for an elliptic curve pairing check
Bn256PairingPerPointGasIstanbul uint64 = 34000 // Per-point price for an elliptic curve pairing check
)

var (
Expand Down

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