core, vm, common: define constantinople fork + shift (#16045)

* core, vm, common: define constantinople fork, start implementation of shift instructions

* vm: more testcases

* vm: add tests for intpool erroneous intpool handling

* core, vm, common: fix constantinople review concerns

* vm: add string<->op definitions for new opcodes

cmd/puppeth/module_dashboard.go

@@ -631,6 +631,7 @@ func deployDashboard(client *sshClient, network string, conf *config, config *da
 		"Tangerine":        conf.Genesis.Config.EIP150Block,
 		"Spurious":         conf.Genesis.Config.EIP155Block,
 		"Byzantium":        conf.Genesis.Config.ByzantiumBlock,
+		"Constantinople":   conf.Genesis.Config.ConstantinopleBlock,
 	})
 	files[filepath.Join(workdir, "index.html")] = indexfile.Bytes()
 

common/big.go

@@ -25,6 +25,6 @@ var (
 	Big3   = big.NewInt(3)
 	Big0   = big.NewInt(0)
 	Big32  = big.NewInt(32)
-	Big256 = big.NewInt(0xff)
+	Big256 = big.NewInt(256)
 	Big257 = big.NewInt(257)
 )

core/vm/instructions.go

@@ -302,6 +302,66 @@ func opMulmod(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *S
 	return nil, nil
 }
 
+// opSHL implements Shift Left
+// The SHL instruction (shift left) pops 2 values from the stack, first arg1 and then arg2,
+// and pushes on the stack arg2 shifted to the left by arg1 number of bits.
+func opSHL(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	// Note, second operand is left in the stack; accumulate result into it, and no need to push it afterwards
+	shift, value := math.U256(stack.pop()), math.U256(stack.peek())
+	defer evm.interpreter.intPool.put(shift) // First operand back into the pool
+
+	if shift.Cmp(common.Big256) >= 0 {
+		value.SetUint64(0)
+		return nil, nil
+	}
+	n := uint(shift.Uint64())
+	math.U256(value.Lsh(value, n))
+
+	return nil, nil
+}
+
+// opSHR implements Logical Shift Right
+// The SHR instruction (logical shift right) pops 2 values from the stack, first arg1 and then arg2,
+// and pushes on the stack arg2 shifted to the right by arg1 number of bits with zero fill.
+func opSHR(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	// Note, second operand is left in the stack; accumulate result into it, and no need to push it afterwards
+	shift, value := math.U256(stack.pop()), math.U256(stack.peek())
+	defer evm.interpreter.intPool.put(shift) // First operand back into the pool
+
+	if shift.Cmp(common.Big256) >= 0 {
+		value.SetUint64(0)
+		return nil, nil
+	}
+	n := uint(shift.Uint64())
+	math.U256(value.Rsh(value, n))
+
+	return nil, nil
+}
+
+// opSAR implements Arithmetic Shift Right
+// The SAR instruction (arithmetic shift right) pops 2 values from the stack, first arg1 and then arg2,
+// and pushes on the stack arg2 shifted to the right by arg1 number of bits with sign extension.
+func opSAR(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	// Note, S256 returns (potentially) a new bigint, so we're popping, not peeking this one
+	shift, value := math.U256(stack.pop()), math.S256(stack.pop())
+	defer evm.interpreter.intPool.put(shift) // First operand back into the pool
+
+	if shift.Cmp(common.Big256) >= 0 {
+		if value.Sign() > 0 {
+			value.SetUint64(0)
+		} else {
+			value.SetInt64(-1)
+		}
+		stack.push(math.U256(value))
+		return nil, nil
+	}
+	n := uint(shift.Uint64())
+	value.Rsh(value, n)
+	stack.push(math.U256(value))
+
+	return nil, nil
+}
+
 func opSha3(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	offset, size := stack.pop(), stack.pop()
 	data := memory.Get(offset.Int64(), size.Int64())

core/vm/instructions_test.go

@@ -24,6 +24,48 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 )
 
+type twoOperandTest struct {
+	x        string
+	y        string
+	expected string
+}
+
+func testTwoOperandOp(t *testing.T, tests []twoOperandTest, opFn func(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error)) {
+	var (
+		env   = NewEVM(Context{}, nil, params.TestChainConfig, Config{EnableJit: false, ForceJit: false})
+		stack = newstack()
+		pc    = uint64(0)
+	)
+	for i, test := range tests {
+		x := new(big.Int).SetBytes(common.Hex2Bytes(test.x))
+		shift := new(big.Int).SetBytes(common.Hex2Bytes(test.y))
+		expected := new(big.Int).SetBytes(common.Hex2Bytes(test.expected))
+		stack.push(x)
+		stack.push(shift)
+		opFn(&pc, env, nil, nil, stack)
+		actual := stack.pop()
+		if actual.Cmp(expected) != 0 {
+			t.Errorf("Testcase %d, expected  %v, got %v", i, expected, actual)
+		}
+		// Check pool usage
+		// 1.pool is not allowed to contain anything on the stack
+		// 2.pool is not allowed to contain the same pointers twice
+		if env.interpreter.intPool.pool.len() > 0 {
+
+			poolvals := make(map[*big.Int]struct{})
+			poolvals[actual] = struct{}{}
+
+			for env.interpreter.intPool.pool.len() > 0 {
+				key := env.interpreter.intPool.get()
+				if _, exist := poolvals[key]; exist {
+					t.Errorf("Testcase %d, pool contains double-entry", i)
+				}
+				poolvals[key] = struct{}{}
+			}
+		}
+	}
+}
+
 func TestByteOp(t *testing.T) {
 	var (
 		env   = NewEVM(Context{}, nil, params.TestChainConfig, Config{EnableJit: false, ForceJit: false})
@@ -57,6 +99,98 @@ func TestByteOp(t *testing.T) {
 	}
 }
 
+func TestSHL(t *testing.T) {
+	// Testcases from https://github.com/ethereum/EIPs/blob/master/EIPS/eip-145.md#shl-shift-left
+	tests := []twoOperandTest{
+		{"0000000000000000000000000000000000000000000000000000000000000001", "00", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "01", "0000000000000000000000000000000000000000000000000000000000000002"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "ff", "8000000000000000000000000000000000000000000000000000000000000000"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "0100", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "0101", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "00", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "01", "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "ff", "8000000000000000000000000000000000000000000000000000000000000000"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0100", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"0000000000000000000000000000000000000000000000000000000000000000", "01", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "01", "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe"},
+	}
+	testTwoOperandOp(t, tests, opSHL)
+}
+
+func TestSHR(t *testing.T) {
+	// Testcases from https://github.com/ethereum/EIPs/blob/master/EIPS/eip-145.md#shr-logical-shift-right
+	tests := []twoOperandTest{
+		{"0000000000000000000000000000000000000000000000000000000000000001", "00", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "01", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "01", "4000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "ff", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "0100", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "0101", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "00", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "01", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "ff", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0100", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"0000000000000000000000000000000000000000000000000000000000000000", "01", "0000000000000000000000000000000000000000000000000000000000000000"},
+	}
+	testTwoOperandOp(t, tests, opSHR)
+}
+
+func TestSAR(t *testing.T) {
+	// Testcases from https://github.com/ethereum/EIPs/blob/master/EIPS/eip-145.md#sar-arithmetic-shift-right
+	tests := []twoOperandTest{
+		{"0000000000000000000000000000000000000000000000000000000000000001", "00", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "01", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "01", "c000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "ff", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "0100", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"8000000000000000000000000000000000000000000000000000000000000000", "0101", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "00", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "01", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "ff", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0100", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},
+		{"0000000000000000000000000000000000000000000000000000000000000000", "01", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"4000000000000000000000000000000000000000000000000000000000000000", "fe", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "f8", "000000000000000000000000000000000000000000000000000000000000007f"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "fe", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "ff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0100", "0000000000000000000000000000000000000000000000000000000000000000"},
+	}
+
+	testTwoOperandOp(t, tests, opSAR)
+}
+
+func TestSGT(t *testing.T) {
+	tests := []twoOperandTest{
+		{"0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000001", "8000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000001", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "8000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000"},
+	}
+	testTwoOperandOp(t, tests, opSgt)
+}
+
+func TestSLT(t *testing.T) {
+	tests := []twoOperandTest{
+		{"0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"0000000000000000000000000000000000000000000000000000000000000001", "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000001"},
+		{"8000000000000000000000000000000000000000000000000000000000000001", "8000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"8000000000000000000000000000000000000000000000000000000000000001", "7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0000000000000000000000000000000000000000000000000000000000000000"},
+		{"7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "8000000000000000000000000000000000000000000000000000000000000001", "0000000000000000000000000000000000000000000000000000000000000001"},
+	}
+	testTwoOperandOp(t, tests, opSlt)
+}
+
 func opBenchmark(bench *testing.B, op func(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error), args ...string) {
 	var (
 		env   = NewEVM(Context{}, nil, params.TestChainConfig, Config{EnableJit: false, ForceJit: false})
@@ -259,3 +393,22 @@ func BenchmarkOpMulmod(b *testing.B) {
 
 	opBenchmark(b, opMulmod, x, y, z)
 }
+
+func BenchmarkOpSHL(b *testing.B) {
+	x := "FBCDEF090807060504030201ffffffffFBCDEF090807060504030201ffffffff"
+	y := "ff"
+
+	opBenchmark(b, opSHL, x, y)
+}
+func BenchmarkOpSHR(b *testing.B) {
+	x := "FBCDEF090807060504030201ffffffffFBCDEF090807060504030201ffffffff"
+	y := "ff"
+
+	opBenchmark(b, opSHR, x, y)
+}
+func BenchmarkOpSAR(b *testing.B) {
+	x := "FBCDEF090807060504030201ffffffffFBCDEF090807060504030201ffffffff"
+	y := "ff"
+
+	opBenchmark(b, opSAR, x, y)
+}

core/vm/interpreter.go

@@ -68,6 +68,8 @@ func NewInterpreter(evm *EVM, cfg Config) *Interpreter {
 	// we'll set the default jump table.
 	if !cfg.JumpTable[STOP].valid {
 		switch {
+		case evm.ChainConfig().IsConstantinople(evm.BlockNumber):
+			cfg.JumpTable = constantinopleInstructionSet
 		case evm.ChainConfig().IsByzantium(evm.BlockNumber):
 			cfg.JumpTable = byzantiumInstructionSet
 		case evm.ChainConfig().IsHomestead(evm.BlockNumber):

core/vm/jump_table.go

@@ -54,8 +54,35 @@ var (
 	frontierInstructionSet       = NewFrontierInstructionSet()
 	homesteadInstructionSet      = NewHomesteadInstructionSet()
 	byzantiumInstructionSet      = NewByzantiumInstructionSet()
+	constantinopleInstructionSet = NewConstantinopleInstructionSet()
 )
 
+// NewConstantinopleInstructionSet returns the frontier, homestead
+// byzantium and contantinople instructions.
+func NewConstantinopleInstructionSet() [256]operation {
+	// instructions that can be executed during the byzantium phase.
+	instructionSet := NewByzantiumInstructionSet()
+	instructionSet[SHL] = operation{
+		execute:       opSHL,
+		gasCost:       constGasFunc(GasFastestStep),
+		validateStack: makeStackFunc(2, 1),
+		valid:         true,
+	}
+	instructionSet[SHR] = operation{
+		execute:       opSHR,
+		gasCost:       constGasFunc(GasFastestStep),
+		validateStack: makeStackFunc(2, 1),
+		valid:         true,
+	}
+	instructionSet[SAR] = operation{
+		execute:       opSAR,
+		gasCost:       constGasFunc(GasFastestStep),
+		validateStack: makeStackFunc(2, 1),
+		valid:         true,
+	}
+	return instructionSet
+}
+
 // NewByzantiumInstructionSet returns the frontier, homestead and
 // byzantium instructions.
 func NewByzantiumInstructionSet() [256]operation {

core/vm/opcodes.go

@@ -63,6 +63,9 @@ const (
 	XOR
 	NOT
 	BYTE
+	SHL
+	SHR
+	SAR
 
 	SHA3 = 0x20
 )
@@ -234,6 +237,9 @@ var opCodeToString = map[OpCode]string{
 	OR:     "OR",
 	XOR:    "XOR",
 	BYTE:   "BYTE",
+	SHL:    "SHL",
+	SHR:    "SHR",
+	SAR:    "SAR",
 	ADDMOD: "ADDMOD",
 	MULMOD: "MULMOD",
 
@@ -400,6 +406,9 @@ var stringToOp = map[string]OpCode{
 	"OR":             OR,
 	"XOR":            XOR,
 	"BYTE":           BYTE,
+	"SHL":            SHL,
+	"SHR":            SHR,
+	"SAR":            SAR,
 	"ADDMOD":         ADDMOD,
 	"MULMOD":         MULMOD,
 	"SHA3":           SHA3,

params/config.go

@@ -40,7 +40,7 @@ var (
 		EIP155Block:         big.NewInt(2675000),
 		EIP158Block:         big.NewInt(2675000),
 		ByzantiumBlock:      big.NewInt(4370000),
-
+		ConstantinopleBlock: nil,
 		Ethash:              new(EthashConfig),
 	}
 
@@ -55,7 +55,7 @@ var (
 		EIP155Block:         big.NewInt(10),
 		EIP158Block:         big.NewInt(10),
 		ByzantiumBlock:      big.NewInt(1700000),
-
+		ConstantinopleBlock: nil,
 		Ethash:              new(EthashConfig),
 	}
 
@@ -70,7 +70,7 @@ var (
 		EIP155Block:         big.NewInt(3),
 		EIP158Block:         big.NewInt(3),
 		ByzantiumBlock:      big.NewInt(1035301),
-
+		ConstantinopleBlock: nil,
 		Clique: &CliqueConfig{
 			Period: 15,
 			Epoch:  30000,
@@ -82,16 +82,16 @@ 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), 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), 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), 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), 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), 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), nil, new(EthashConfig), nil}
 	TestRules       = TestChainConfig.Rules(new(big.Int))
 )
 
@@ -116,6 +116,7 @@ type ChainConfig struct {
 	EIP158Block *big.Int `json:"eip158Block,omitempty"` // EIP158 HF block
 
 	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)
 
 	// Various consensus engines
 	Ethash *EthashConfig `json:"ethash,omitempty"`
@@ -152,7 +153,7 @@ 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 Engine: %v}",
+	return fmt.Sprintf("{ChainID: %v Homestead: %v DAO: %v DAOSupport: %v EIP150: %v EIP155: %v EIP158: %v Byzantium: %v Constantinople: %v Engine: %v}",
 		c.ChainId,
 		c.HomesteadBlock,
 		c.DAOForkBlock,
@@ -161,6 +162,7 @@ func (c *ChainConfig) String() string {
 		c.EIP155Block,
 		c.EIP158Block,
 		c.ByzantiumBlock,
+		c.ConstantinopleBlock,
 		engine,
 	)
 }
@@ -191,6 +193,10 @@ func (c *ChainConfig) IsByzantium(num *big.Int) bool {
 	return isForked(c.ByzantiumBlock, num)
 }
 
+func (c *ChainConfig) IsConstantinople(num *big.Int) bool {
+	return isForked(c.ConstantinopleBlock, num)
+}
+
 // GasTable returns the gas table corresponding to the current phase (homestead or homestead reprice).
 //
 // The returned GasTable's fields shouldn't, under any circumstances, be changed.
@@ -251,6 +257,9 @@ func (c *ChainConfig) checkCompatible(newcfg *ChainConfig, head *big.Int) *Confi
 	if isForkIncompatible(c.ByzantiumBlock, newcfg.ByzantiumBlock, head) {
 		return newCompatError("Byzantium fork block", c.ByzantiumBlock, newcfg.ByzantiumBlock)
 	}
+	if isForkIncompatible(c.ConstantinopleBlock, newcfg.ConstantinopleBlock, head) {
+		return newCompatError("Constantinople fork block", c.ConstantinopleBlock, newcfg.ConstantinopleBlock)
+	}
 	return nil
 }