Revert "params: core, core/vm, miner: 64bit gas instructions (#3514)"

This reverts commit 8b57c494908637a5c0e74f8f7a13b3218e026757.

25 files changed, 922 insertions, 1076 deletions

diff --git a/core/bench_test.go b/core/bench_test.go
index 59b5ad758..353d217fd 100644
--- a/core/bench_test.go
+++ b/core/bench_test.go
@@ -92,7 +92,6 @@ func genValueTx(nbytes int) func(int, *BlockGen) {
 var (
 	ringKeys  = make([]*ecdsa.PrivateKey, 1000)
 	ringAddrs = make([]common.Address, len(ringKeys))
-	bigTxGas  = new(big.Int).SetUint64(params.TxGas)
 )
 
 func init() {
@@ -112,8 +111,8 @@ func genTxRing(naccounts int) func(int, *BlockGen) {
 	return func(i int, gen *BlockGen) {
 		gas := CalcGasLimit(gen.PrevBlock(i - 1))
 		for {
-			gas.Sub(gas, bigTxGas)
-			if gas.Cmp(bigTxGas) < 0 {
+			gas.Sub(gas, params.TxGas)
+			if gas.Cmp(params.TxGas) < 0 {
 				break
 			}
 			to := (from + 1) % naccounts
@@ -121,7 +120,7 @@ func genTxRing(naccounts int) func(int, *BlockGen) {
 				gen.TxNonce(ringAddrs[from]),
 				ringAddrs[to],
 				benchRootFunds,
-				bigTxGas,
+				params.TxGas,
 				nil,
 				nil,
 			)
diff --git a/core/block_validator.go b/core/block_validator.go
index ee524b61f..65f975345 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -204,7 +204,7 @@ func (v *BlockValidator) ValidateHeader(header, parent *types.Header, checkPow b
 //
 // See YP section 4.3.4. "Block Header Validity"
 func ValidateHeader(config *params.ChainConfig, pow pow.PoW, header *types.Header, parent *types.Header, checkPow, uncle bool) error {
-	if uint64(len(header.Extra)) > params.MaximumExtraDataSize {
+	if big.NewInt(int64(len(header.Extra))).Cmp(params.MaximumExtraDataSize) == 1 {
 		return fmt.Errorf("Header extra data too long (%d)", len(header.Extra))
 	}
 
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index cdf9b5cc6..8f1383acd 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -719,7 +719,7 @@ func TestFastVsFullChains(t *testing.T) {
 		// If the block number is multiple of 3, send a few bonus transactions to the miner
 		if i%3 == 2 {
 			for j := 0; j < i%4+1; j++ {
-				tx, err := types.SignTx(types.NewTransaction(block.TxNonce(address), common.Address{0x00}, big.NewInt(1000), bigTxGas, nil, nil), signer, key)
+				tx, err := types.SignTx(types.NewTransaction(block.TxNonce(address), common.Address{0x00}, big.NewInt(1000), params.TxGas, nil, nil), signer, key)
 				if err != nil {
 					panic(err)
 				}
@@ -883,8 +883,8 @@ func TestChainTxReorgs(t *testing.T) {
 	// Create two transactions shared between the chains:
 	//  - postponed: transaction included at a later block in the forked chain
 	//  - swapped: transaction included at the same block number in the forked chain
-	postponed, _ := types.SignTx(types.NewTransaction(0, addr1, big.NewInt(1000), bigTxGas, nil, nil), signer, key1)
-	swapped, _ := types.SignTx(types.NewTransaction(1, addr1, big.NewInt(1000), bigTxGas, nil, nil), signer, key1)
+	postponed, _ := types.SignTx(types.NewTransaction(0, addr1, big.NewInt(1000), params.TxGas, nil, nil), signer, key1)
+	swapped, _ := types.SignTx(types.NewTransaction(1, addr1, big.NewInt(1000), params.TxGas, nil, nil), signer, key1)
 
 	// Create two transactions that will be dropped by the forked chain:
 	//  - pastDrop: transaction dropped retroactively from a past block
@@ -900,13 +900,13 @@ func TestChainTxReorgs(t *testing.T) {
 	chain, _ := GenerateChain(params.TestChainConfig, genesis, db, 3, func(i int, gen *BlockGen) {
 		switch i {
 		case 0:
-			pastDrop, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr2, big.NewInt(1000), bigTxGas, nil, nil), signer, key2)
+			pastDrop, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr2, big.NewInt(1000), params.TxGas, nil, nil), signer, key2)
 
 			gen.AddTx(pastDrop)  // This transaction will be dropped in the fork from below the split point
 			gen.AddTx(postponed) // This transaction will be postponed till block #3 in the fork
 
 		case 2:
-			freshDrop, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr2, big.NewInt(1000), bigTxGas, nil, nil), signer, key2)
+			freshDrop, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr2, big.NewInt(1000), params.TxGas, nil, nil), signer, key2)
 
 			gen.AddTx(freshDrop) // This transaction will be dropped in the fork from exactly at the split point
 			gen.AddTx(swapped)   // This transaction will be swapped out at the exact height
@@ -925,18 +925,18 @@ func TestChainTxReorgs(t *testing.T) {
 	chain, _ = GenerateChain(params.TestChainConfig, genesis, db, 5, func(i int, gen *BlockGen) {
 		switch i {
 		case 0:
-			pastAdd, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr3), addr3, big.NewInt(1000), bigTxGas, nil, nil), signer, key3)
+			pastAdd, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr3), addr3, big.NewInt(1000), params.TxGas, nil, nil), signer, key3)
 			gen.AddTx(pastAdd) // This transaction needs to be injected during reorg
 
 		case 2:
 			gen.AddTx(postponed) // This transaction was postponed from block #1 in the original chain
 			gen.AddTx(swapped)   // This transaction was swapped from the exact current spot in the original chain
 
-			freshAdd, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr3), addr3, big.NewInt(1000), bigTxGas, nil, nil), signer, key3)
+			freshAdd, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr3), addr3, big.NewInt(1000), params.TxGas, nil, nil), signer, key3)
 			gen.AddTx(freshAdd) // This transaction will be added exactly at reorg time
 
 		case 3:
-			futureAdd, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr3), addr3, big.NewInt(1000), bigTxGas, nil, nil), signer, key3)
+			futureAdd, _ = types.SignTx(types.NewTransaction(gen.TxNonce(addr3), addr3, big.NewInt(1000), params.TxGas, nil, nil), signer, key3)
 			gen.AddTx(futureAdd) // This transaction will be added after a full reorg
 		}
 	})
diff --git a/core/chain_makers_test.go b/core/chain_makers_test.go
index 5c563de46..2796817c0 100644
--- a/core/chain_makers_test.go
+++ b/core/chain_makers_test.go
@@ -56,13 +56,13 @@ func ExampleGenerateChain() {
 		switch i {
 		case 0:
 			// In block 1, addr1 sends addr2 some ether.
-			tx, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(10000), bigTxGas, nil, nil), signer, key1)
+			tx, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(10000), params.TxGas, nil, nil), signer, key1)
 			gen.AddTx(tx)
 		case 1:
 			// In block 2, addr1 sends some more ether to addr2.
 			// addr2 passes it on to addr3.
-			tx1, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(1000), bigTxGas, nil, nil), signer, key1)
-			tx2, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr3, big.NewInt(1000), bigTxGas, nil, nil), signer, key2)
+			tx1, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr1), addr2, big.NewInt(1000), params.TxGas, nil, nil), signer, key1)
+			tx2, _ := types.SignTx(types.NewTransaction(gen.TxNonce(addr2), addr3, big.NewInt(1000), params.TxGas, nil, nil), signer, key2)
 			gen.AddTx(tx1)
 			gen.AddTx(tx2)
 		case 2:
diff --git a/core/state_transition.go b/core/state_transition.go
index 98dc8d995..3cb7e500c 100644
--- a/core/state_transition.go
+++ b/core/state_transition.go
@@ -49,16 +49,15 @@ The state transitioning model does all all the necessary work to work out a vali
 6) Derive new state root
 */
 type StateTransition struct {
-	gp         *GasPool
-	msg        Message
-	gas        uint64
-	gasPrice   *big.Int
-	initialGas *big.Int
-	value      *big.Int
-	data       []byte
-	state      vm.StateDB
-
-	evm *vm.EVM
+	gp            *GasPool
+	msg           Message
+	gas, gasPrice *big.Int
+	initialGas    *big.Int
+	value         *big.Int
+	data          []byte
+	state         vm.StateDB
+
+	env *vm.EVM
 }
 
 // Message represents a message sent to a contract.
@@ -82,14 +81,12 @@ func MessageCreatesContract(msg Message) bool {
 
 // IntrinsicGas computes the 'intrinsic gas' for a message
 // with the given data.
-//
-// TODO convert to uint64
 func IntrinsicGas(data []byte, contractCreation, homestead bool) *big.Int {
 	igas := new(big.Int)
 	if contractCreation && homestead {
-		igas.SetUint64(params.TxGasContractCreation)
+		igas.Set(params.TxGasContractCreation)
 	} else {
-		igas.SetUint64(params.TxGas)
+		igas.Set(params.TxGas)
 	}
 	if len(data) > 0 {
 		var nz int64
@@ -99,26 +96,27 @@ func IntrinsicGas(data []byte, contractCreation, homestead bool) *big.Int {
 			}
 		}
 		m := big.NewInt(nz)
-		m.Mul(m, new(big.Int).SetUint64(params.TxDataNonZeroGas))
+		m.Mul(m, params.TxDataNonZeroGas)
 		igas.Add(igas, m)
 		m.SetInt64(int64(len(data)) - nz)
-		m.Mul(m, new(big.Int).SetUint64(params.TxDataZeroGas))
+		m.Mul(m, params.TxDataZeroGas)
 		igas.Add(igas, m)
 	}
 	return igas
 }
 
 // NewStateTransition initialises and returns a new state transition object.
-func NewStateTransition(evm *vm.EVM, msg Message, gp *GasPool) *StateTransition {
+func NewStateTransition(env *vm.EVM, msg Message, gp *GasPool) *StateTransition {
 	return &StateTransition{
 		gp:         gp,
-		evm:        evm,
+		env:        env,
 		msg:        msg,
+		gas:        new(big.Int),
 		gasPrice:   msg.GasPrice(),
 		initialGas: new(big.Int),
 		value:      msg.Value(),
 		data:       msg.Data(),
-		state:      evm.StateDB,
+		state:      env.StateDB,
 	}
 }
 
@@ -129,8 +127,8 @@ func NewStateTransition(evm *vm.EVM, msg Message, gp *GasPool) *StateTransition
 // the gas used (which includes gas refunds) and an error if it failed. An error always
 // indicates a core error meaning that the message would always fail for that particular
 // state and would never be accepted within a block.
-func ApplyMessage(evm *vm.EVM, msg Message, gp *GasPool) ([]byte, *big.Int, error) {
-	st := NewStateTransition(evm, msg, gp)
+func ApplyMessage(env *vm.EVM, msg Message, gp *GasPool) ([]byte, *big.Int, error) {
+	st := NewStateTransition(env, msg, gp)
 
 	ret, _, gasUsed, err := st.TransitionDb()
 	return ret, gasUsed, err
@@ -159,21 +157,21 @@ func (self *StateTransition) to() vm.Account {
 	return self.state.GetAccount(*to)
 }
 
-func (self *StateTransition) useGas(amount uint64) error {
-	if self.gas < amount {
+func (self *StateTransition) useGas(amount *big.Int) error {
+	if self.gas.Cmp(amount) < 0 {
 		return vm.ErrOutOfGas
 	}
-	self.gas -= amount
+	self.gas.Sub(self.gas, amount)
 
 	return nil
 }
 
+func (self *StateTransition) addGas(amount *big.Int) {
+	self.gas.Add(self.gas, amount)
+}
+
 func (self *StateTransition) buyGas() error {
 	mgas := self.msg.Gas()
-	if mgas.BitLen() > 64 {
-		return vm.ErrOutOfGas
-	}
-
 	mgval := new(big.Int).Mul(mgas, self.gasPrice)
 
 	sender := self.from()
@@ -183,8 +181,7 @@ func (self *StateTransition) buyGas() error {
 	if err := self.gp.SubGas(mgas); err != nil {
 		return err
 	}
-	self.gas += mgas.Uint64()
-
+	self.addGas(mgas)
 	self.initialGas.Set(mgas)
 	sender.SubBalance(mgval)
 	return nil
@@ -212,9 +209,7 @@ func (self *StateTransition) preCheck() (err error) {
 	return nil
 }
 
-// TransitionDb will transition the state by applying the current message and returning the result
-// including the required gas for the operation as well as the used gas. It returns an error if it
-// failed. An error indicates a consensus issue.
+// TransitionDb will move the state by applying the message against the given environment.
 func (self *StateTransition) TransitionDb() (ret []byte, requiredGas, usedGas *big.Int, err error) {
 	if err = self.preCheck(); err != nil {
 		return
@@ -222,32 +217,26 @@ func (self *StateTransition) TransitionDb() (ret []byte, requiredGas, usedGas *b
 	msg := self.msg
 	sender := self.from() // err checked in preCheck
 
-	homestead := self.evm.ChainConfig().IsHomestead(self.evm.BlockNumber)
+	homestead := self.env.ChainConfig().IsHomestead(self.env.BlockNumber)
 	contractCreation := MessageCreatesContract(msg)
 	// Pay intrinsic gas
-	// TODO convert to uint64
-	intrinsicGas := IntrinsicGas(self.data, contractCreation, homestead)
-	if intrinsicGas.BitLen() > 64 {
-		return nil, nil, nil, InvalidTxError(vm.ErrOutOfGas)
-	}
-
-	if err = self.useGas(intrinsicGas.Uint64()); err != nil {
+	if err = self.useGas(IntrinsicGas(self.data, contractCreation, homestead)); err != nil {
 		return nil, nil, nil, InvalidTxError(err)
 	}
 
 	var (
-		evm = self.evm
+		vmenv = self.env
 		// vm errors do not effect consensus and are therefor
 		// not assigned to err, except for insufficient balance
 		// error.
 		vmerr error
 	)
 	if contractCreation {
-		ret, _, self.gas, vmerr = evm.Create(sender, self.data, self.gas, self.value)
+		ret, _, vmerr = vmenv.Create(sender, self.data, self.gas, self.value)
 	} else {
 		// Increment the nonce for the next transaction
 		self.state.SetNonce(sender.Address(), self.state.GetNonce(sender.Address())+1)
-		ret, self.gas, vmerr = evm.Call(sender, self.to().Address(), self.data, self.gas, self.value)
+		ret, vmerr = vmenv.Call(sender, self.to().Address(), self.data, self.gas, self.value)
 	}
 	if vmerr != nil {
 		glog.V(logger.Core).Infoln("vm returned with error:", err)
@@ -262,7 +251,7 @@ func (self *StateTransition) TransitionDb() (ret []byte, requiredGas, usedGas *b
 	requiredGas = new(big.Int).Set(self.gasUsed())
 
 	self.refundGas()
-	self.state.AddBalance(self.evm.Coinbase, new(big.Int).Mul(self.gasUsed(), self.gasPrice))
+	self.state.AddBalance(self.env.Coinbase, new(big.Int).Mul(self.gasUsed(), self.gasPrice))
 
 	return ret, requiredGas, self.gasUsed(), err
 }
@@ -271,21 +260,20 @@ func (self *StateTransition) refundGas() {
 	// Return eth for remaining gas to the sender account,
 	// exchanged at the original rate.
 	sender := self.from() // err already checked
-	remaining := new(big.Int).Mul(new(big.Int).SetUint64(self.gas), self.gasPrice)
+	remaining := new(big.Int).Mul(self.gas, self.gasPrice)
 	sender.AddBalance(remaining)
 
 	// Apply refund counter, capped to half of the used gas.
 	uhalf := remaining.Div(self.gasUsed(), common.Big2)
 	refund := common.BigMin(uhalf, self.state.GetRefund())
-	self.gas += refund.Uint64()
-
+	self.gas.Add(self.gas, refund)
 	self.state.AddBalance(sender.Address(), refund.Mul(refund, self.gasPrice))
 
 	// Also return remaining gas to the block gas counter so it is
 	// available for the next transaction.
-	self.gp.AddGas(new(big.Int).SetUint64(self.gas))
+	self.gp.AddGas(self.gas)
 }
 
 func (self *StateTransition) gasUsed() *big.Int {
-	return new(big.Int).Sub(self.initialGas, new(big.Int).SetUint64(self.gas))
+	return new(big.Int).Sub(self.initialGas, self.gas)
 }
diff --git a/core/vm/common.go b/core/vm/common.go
index b7b9a6a9c..2878b92d2 100644
--- a/core/vm/common.go
+++ b/core/vm/common.go
@@ -21,11 +21,28 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+// Type is the VM type accepted by **NewVm**
+type Type byte
+
+const (
+	StdVmTy Type = iota // Default standard VM
+	JitVmTy             // LLVM JIT VM
+	MaxVmTy
 )
 
 var (
+	Pow256 = common.BigPow(2, 256) // Pow256 is 2**256
+
 	U256 = common.U256 // Shortcut to common.U256
 	S256 = common.S256 // Shortcut to common.S256
+
+	Zero = common.Big0 // Shortcut to common.Big0
+	One  = common.Big1 // Shortcut to common.Big1
+
+	max = big.NewInt(math.MaxInt64) // Maximum 64 bit integer
 )
 
 // calculates the memory size required for a step
@@ -37,6 +54,48 @@ func calcMemSize(off, l *big.Int) *big.Int {
 	return new(big.Int).Add(off, l)
 }
 
+// calculates the quadratic gas
+func quadMemGas(mem *Memory, newMemSize, gas *big.Int) {
+	if newMemSize.Cmp(common.Big0) > 0 {
+		newMemSizeWords := toWordSize(newMemSize)
+		newMemSize.Mul(newMemSizeWords, u256(32))
+
+		if newMemSize.Cmp(u256(int64(mem.Len()))) > 0 {
+			// be careful reusing variables here when changing.
+			// The order has been optimised to reduce allocation
+			oldSize := toWordSize(big.NewInt(int64(mem.Len())))
+			pow := new(big.Int).Exp(oldSize, common.Big2, Zero)
+			linCoef := oldSize.Mul(oldSize, params.MemoryGas)
+			quadCoef := new(big.Int).Div(pow, params.QuadCoeffDiv)
+			oldTotalFee := new(big.Int).Add(linCoef, quadCoef)
+
+			pow.Exp(newMemSizeWords, common.Big2, Zero)
+			linCoef = linCoef.Mul(newMemSizeWords, params.MemoryGas)
+			quadCoef = quadCoef.Div(pow, params.QuadCoeffDiv)
+			newTotalFee := linCoef.Add(linCoef, quadCoef)
+
+			fee := newTotalFee.Sub(newTotalFee, oldTotalFee)
+			gas.Add(gas, fee)
+		}
+	}
+}
+
+// Simple helper
+func u256(n int64) *big.Int {
+	return big.NewInt(n)
+}
+
+// Mainly used for print variables and passing to Print*
+func toValue(val *big.Int) interface{} {
+	// Let's assume a string on right padded zero's
+	b := val.Bytes()
+	if b[0] != 0 && b[len(b)-1] == 0x0 && b[len(b)-2] == 0x0 {
+		return string(b)
+	}
+
+	return val
+}
+
 // getData returns a slice from the data based on the start and size and pads
 // up to size with zero's. This function is overflow safe.
 func getData(data []byte, start, size *big.Int) []byte {
@@ -47,17 +106,14 @@ func getData(data []byte, start, size *big.Int) []byte {
 	return common.RightPadBytes(data[s.Uint64():e.Uint64()], int(size.Uint64()))
 }
 
-// bigUint64 returns the integer casted to a uint64 and returns whether it
-// overflowed in the process.
-func bigUint64(v *big.Int) (uint64, bool) {
-	return v.Uint64(), v.BitLen() > 64
-}
-
-// toWordSize returns the ceiled word size required for memory expansion.
-func toWordSize(size uint64) uint64 {
-	if size > math.MaxUint64-31 {
-		return math.MaxUint64/32 + 1
+// useGas attempts to subtract the amount of gas and returns whether it was
+// successful
+func useGas(gas, amount *big.Int) bool {
+	if gas.Cmp(amount) < 0 {
+		return false
 	}
 
-	return (size + 31) / 32
+	// Sub the amount of gas from the remaining
+	gas.Sub(gas, amount)
+	return true
 }
diff --git a/core/vm/contract.go b/core/vm/contract.go
index 091106d84..dfa93ab18 100644
--- a/core/vm/contract.go
+++ b/core/vm/contract.go
@@ -24,6 +24,7 @@ import (
 
 // ContractRef is a reference to the contract's backing object
 type ContractRef interface {
+	ReturnGas(*big.Int)
 	Address() common.Address
 	Value() *big.Int
 	SetCode(common.Hash, []byte)
@@ -47,8 +48,7 @@ type Contract struct {
 	CodeAddr *common.Address
 	Input    []byte
 
-	Gas   uint64
-	value *big.Int
+	value, Gas, UsedGas *big.Int
 
 	Args []byte
 
@@ -56,7 +56,7 @@ type Contract struct {
 }
 
 // NewContract returns a new contract environment for the execution of EVM.
-func NewContract(caller ContractRef, object ContractRef, value *big.Int, gas uint64) *Contract {
+func NewContract(caller ContractRef, object ContractRef, value, gas *big.Int) *Contract {
 	c := &Contract{CallerAddress: caller.Address(), caller: caller, self: object, Args: nil}
 
 	if parent, ok := caller.(*Contract); ok {
@@ -68,8 +68,9 @@ func NewContract(caller ContractRef, object ContractRef, value *big.Int, gas uin
 
 	// Gas should be a pointer so it can safely be reduced through the run
 	// This pointer will be off the state transition
-	c.Gas = gas
+	c.Gas = gas //new(big.Int).Set(gas)
 	c.value = new(big.Int).Set(value)
+	c.UsedGas = new(big.Int)
 
 	return c
 }
@@ -106,13 +107,27 @@ func (c *Contract) Caller() common.Address {
 	return c.CallerAddress
 }
 
+// Finalise finalises the contract and returning any remaining gas to the original
+// caller.
+func (c *Contract) Finalise() {
+	// Return the remaining gas to the caller
+	c.caller.ReturnGas(c.Gas)
+}
+
 // UseGas attempts the use gas and subtracts it and returns true on success
-func (c *Contract) UseGas(gas uint64) (ok bool) {
-	if c.Gas < gas {
-		return false
+func (c *Contract) UseGas(gas *big.Int) (ok bool) {
+	ok = useGas(c.Gas, gas)
+	if ok {
+		c.UsedGas.Add(c.UsedGas, gas)
 	}
-	c.Gas -= gas
-	return true
+	return
+}
+
+// ReturnGas adds the given gas back to itself.
+func (c *Contract) ReturnGas(gas *big.Int) {
+	// Return the gas to the context
+	c.Gas.Add(c.Gas, gas)
+	c.UsedGas.Sub(c.UsedGas, gas)
 }
 
 // Address returns the contracts address
diff --git a/core/vm/contracts.go b/core/vm/contracts.go
index 593b6ca55..9645d268f 100644
--- a/core/vm/contracts.go
+++ b/core/vm/contracts.go
@@ -17,6 +17,8 @@
 package vm
 
 import (
+	"math/big"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/logger"
@@ -28,8 +30,8 @@ import (
 // requires a deterministic gas count based on the input size of the Run method of the
 // contract.
 type PrecompiledContract interface {
-	RequiredGas(inputSize int) uint64 // RequiredPrice calculates the contract gas use
-	Run(input []byte) []byte          // Run runs the precompiled contract
+	RequiredGas(inputSize int) *big.Int // RequiredPrice calculates the contract gas use
+	Run(input []byte) []byte            // Run runs the precompiled contract
 }
 
 // Precompiled contains the default set of ethereum contracts
@@ -55,7 +57,7 @@ func RunPrecompiledContract(p PrecompiledContract, input []byte, contract *Contr
 // ECRECOVER implemented as a native contract
 type ecrecover struct{}
 
-func (c *ecrecover) RequiredGas(inputSize int) uint64 {
+func (c *ecrecover) RequiredGas(inputSize int) *big.Int {
 	return params.EcrecoverGas
 }
 
@@ -90,12 +92,10 @@ func (c *ecrecover) Run(in []byte) []byte {
 // SHA256 implemented as a native contract
 type sha256 struct{}
 
-// RequiredGas returns the gas required to execute the pre-compiled contract.
-//
-// This method does not require any overflow checking as the input size gas costs
-// required for anything significant is so high it's impossible to pay for.
-func (c *sha256) RequiredGas(inputSize int) uint64 {
-	return uint64(inputSize+31)/32*params.Sha256WordGas + params.Sha256Gas
+func (c *sha256) RequiredGas(inputSize int) *big.Int {
+	n := big.NewInt(int64(inputSize+31) / 32)
+	n.Mul(n, params.Sha256WordGas)
+	return n.Add(n, params.Sha256Gas)
 }
 func (c *sha256) Run(in []byte) []byte {
 	return crypto.Sha256(in)
@@ -104,12 +104,10 @@ func (c *sha256) Run(in []byte) []byte {
 // RIPMED160 implemented as a native contract
 type ripemd160 struct{}
 
-// RequiredGas returns the gas required to execute the pre-compiled contract.
-//
-// This method does not require any overflow checking as the input size gas costs
-// required for anything significant is so high it's impossible to pay for.
-func (c *ripemd160) RequiredGas(inputSize int) uint64 {
-	return uint64(inputSize+31)/32*params.Ripemd160WordGas + params.Ripemd160Gas
+func (c *ripemd160) RequiredGas(inputSize int) *big.Int {
+	n := big.NewInt(int64(inputSize+31) / 32)
+	n.Mul(n, params.Ripemd160WordGas)
+	return n.Add(n, params.Ripemd160Gas)
 }
 func (c *ripemd160) Run(in []byte) []byte {
 	return common.LeftPadBytes(crypto.Ripemd160(in), 32)
@@ -118,12 +116,11 @@ func (c *ripemd160) Run(in []byte) []byte {
 // data copy implemented as a native contract
 type dataCopy struct{}
 
-// RequiredGas returns the gas required to execute the pre-compiled contract.
-//
-// This method does not require any overflow checking as the input size gas costs
-// required for anything significant is so high it's impossible to pay for.
-func (c *dataCopy) RequiredGas(inputSize int) uint64 {
-	return uint64(inputSize+31)/32*params.IdentityWordGas + params.IdentityGas
+func (c *dataCopy) RequiredGas(inputSize int) *big.Int {
+	n := big.NewInt(int64(inputSize+31) / 32)
+	n.Mul(n, params.IdentityWordGas)
+
+	return n.Add(n, params.IdentityGas)
 }
 func (c *dataCopy) Run(in []byte) []byte {
 	return in
diff --git a/core/vm/evm.go b/core/vm/environment.go
index 0c5d998c2..c19ef464b 100644
--- a/core/vm/evm.go
+++ b/core/vm/environment.go
@@ -17,6 +17,7 @@
 package vm
 
 import (
+	"fmt"
 	"math/big"
 	"sync/atomic"
 
@@ -101,18 +102,24 @@ func (evm *EVM) Cancel() {
 // Call executes the contract associated with the addr with the given input as parameters. It also handles any
 // necessary value transfer required and takes the necessary steps to create accounts and reverses the state in
 // case of an execution error or failed value transfer.
-func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
+func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas, value *big.Int) (ret []byte, err error) {
 	if evm.vmConfig.NoRecursion && evm.depth > 0 {
-		return nil, gas, nil
+		caller.ReturnGas(gas)
+
+		return nil, nil
 	}
 
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
-	if evm.depth > int(params.CallCreateDepth) {
-		return nil, gas, ErrDepth
+	if evm.depth > int(params.CallCreateDepth.Int64()) {
+		caller.ReturnGas(gas)
+
+		return nil, ErrDepth
 	}
 	if !evm.Context.CanTransfer(evm.StateDB, caller.Address(), value) {
-		return nil, gas, ErrInsufficientBalance
+		caller.ReturnGas(gas)
+
+		return nil, ErrInsufficientBalance
 	}
 
 	var (
@@ -121,7 +128,8 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 	)
 	if !evm.StateDB.Exist(addr) {
 		if PrecompiledContracts[addr] == nil && evm.ChainConfig().IsEIP158(evm.BlockNumber) && value.BitLen() == 0 {
-			return nil, gas, nil
+			caller.ReturnGas(gas)
+			return nil, nil
 		}
 
 		to = evm.StateDB.CreateAccount(addr)
@@ -135,6 +143,7 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 	// only.
 	contract := NewContract(caller, to, value, gas)
 	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
+	defer contract.Finalise()
 
 	ret, err = evm.interpreter.Run(contract, input)
 	// When an error was returned by the EVM or when setting the creation code
@@ -145,7 +154,7 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 
 		evm.StateDB.RevertToSnapshot(snapshot)
 	}
-	return ret, contract.Gas, err
+	return ret, err
 }
 
 // CallCode executes the contract associated with the addr with the given input as parameters. It also handles any
@@ -153,18 +162,24 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 // case of an execution error or failed value transfer.
 //
 // CallCode differs from Call in the sense that it executes the given address' code with the caller as context.
-func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
+func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, gas, value *big.Int) (ret []byte, err error) {
 	if evm.vmConfig.NoRecursion && evm.depth > 0 {
-		return nil, gas, nil
+		caller.ReturnGas(gas)
+
+		return nil, nil
 	}
 
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
-	if evm.depth > int(params.CallCreateDepth) {
-		return nil, gas, ErrDepth
+	if evm.depth > int(params.CallCreateDepth.Int64()) {
+		caller.ReturnGas(gas)
+
+		return nil, ErrDepth
 	}
 	if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
-		return nil, gas, ErrInsufficientBalance
+		caller.ReturnGas(gas)
+
+		return nil, fmt.Errorf("insufficient funds to transfer value. Req %v, has %v", value, evm.StateDB.GetBalance(caller.Address()))
 	}
 
 	var (
@@ -176,6 +191,7 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 	// only.
 	contract := NewContract(caller, to, value, gas)
 	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
+	defer contract.Finalise()
 
 	ret, err = evm.interpreter.Run(contract, input)
 	if err != nil {
@@ -184,7 +200,7 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 		evm.StateDB.RevertToSnapshot(snapshot)
 	}
 
-	return ret, contract.Gas, err
+	return ret, err
 }
 
 // DelegateCall executes the contract associated with the addr with the given input as parameters.
@@ -192,15 +208,18 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 //
 // DelegateCall differs from CallCode in the sense that it executes the given address' code with the caller as context
 // and the caller is set to the caller of the caller.
-func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
+func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas *big.Int) (ret []byte, err error) {
 	if evm.vmConfig.NoRecursion && evm.depth > 0 {
-		return nil, gas, nil
+		caller.ReturnGas(gas)
+
+		return nil, nil
 	}
 
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
-	if evm.depth > int(params.CallCreateDepth) {
-		return nil, gas, ErrDepth
+	if evm.depth > int(params.CallCreateDepth.Int64()) {
+		caller.ReturnGas(gas)
+		return nil, ErrDepth
 	}
 
 	var (
@@ -211,6 +230,7 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
 	// Iinitialise a new contract and make initialise the delegate values
 	contract := NewContract(caller, to, caller.Value(), gas).AsDelegate()
 	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
+	defer contract.Finalise()
 
 	ret, err = evm.interpreter.Run(contract, input)
 	if err != nil {
@@ -219,22 +239,28 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
 		evm.StateDB.RevertToSnapshot(snapshot)
 	}
 
-	return ret, contract.Gas, err
+	return ret, err
 }
 
 // Create creates a new contract using code as deployment code.
-func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
+func (evm *EVM) Create(caller ContractRef, code []byte, gas, value *big.Int) (ret []byte, contractAddr common.Address, err error) {
 	if evm.vmConfig.NoRecursion && evm.depth > 0 {
-		return nil, common.Address{}, gas, nil
+		caller.ReturnGas(gas)
+
+		return nil, common.Address{}, nil
 	}
 
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
-	if evm.depth > int(params.CallCreateDepth) {
-		return nil, common.Address{}, gas, ErrDepth
+	if evm.depth > int(params.CallCreateDepth.Int64()) {
+		caller.ReturnGas(gas)
+
+		return nil, common.Address{}, ErrDepth
 	}
 	if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
-		return nil, common.Address{}, gas, ErrInsufficientBalance
+		caller.ReturnGas(gas)
+
+		return nil, common.Address{}, ErrInsufficientBalance
 	}
 
 	// Create a new account on the state
@@ -254,6 +280,7 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
 	// only.
 	contract := NewContract(caller, to, value, gas)
 	contract.SetCallCode(&contractAddr, crypto.Keccak256Hash(code), code)
+	defer contract.Finalise()
 
 	ret, err = evm.interpreter.Run(contract, nil)
 
@@ -264,8 +291,9 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
 	// be stored due to not enough gas set an error and let it be handled
 	// by the error checking condition below.
 	if err == nil && !maxCodeSizeExceeded {
-		createDataGas := uint64(len(ret)) * params.CreateDataGas
-		if contract.UseGas(createDataGas) {
+		dataGas := big.NewInt(int64(len(ret)))
+		dataGas.Mul(dataGas, params.CreateDataGas)
+		if contract.UseGas(dataGas) {
 			evm.StateDB.SetCode(contractAddr, ret)
 		} else {
 			err = ErrCodeStoreOutOfGas
@@ -277,10 +305,11 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
 	// when we're in homestead this also counts for code storage gas errors.
 	if maxCodeSizeExceeded ||
 		(err != nil && (evm.ChainConfig().IsHomestead(evm.BlockNumber) || err != ErrCodeStoreOutOfGas)) {
+		contract.UseGas(contract.Gas)
 		evm.StateDB.RevertToSnapshot(snapshot)
 
 		// Nothing should be returned when an error is thrown.
-		return nil, contractAddr, 0, err
+		return nil, contractAddr, err
 	}
 	// If the vm returned with an error the return value should be set to nil.
 	// This isn't consensus critical but merely to for behaviour reasons such as
@@ -289,7 +318,7 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
 		ret = nil
 	}
 
-	return ret, contractAddr, contract.Gas, err
+	return ret, contractAddr, err
 }
 
 // ChainConfig returns the evmironment's chain configuration
diff --git a/core/vm/gas.go b/core/vm/gas.go
index dd64d5f17..cb225b6ca 100644
--- a/core/vm/gas.go
+++ b/core/vm/gas.go
@@ -17,42 +17,149 @@
 package vm
 
 import (
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/params"
 )
 
-const (
-	GasQuickStep   uint64 = 2
-	GasFastestStep uint64 = 3
-	GasFastStep    uint64 = 5
-	GasMidStep     uint64 = 8
-	GasSlowStep    uint64 = 10
-	GasExtStep     uint64 = 20
-
-	GasReturn       uint64 = 0
-	GasStop         uint64 = 0
-	GasContractByte uint64 = 200
+var (
+	GasQuickStep   = big.NewInt(2)
+	GasFastestStep = big.NewInt(3)
+	GasFastStep    = big.NewInt(5)
+	GasMidStep     = big.NewInt(8)
+	GasSlowStep    = big.NewInt(10)
+	GasExtStep     = big.NewInt(20)
+
+	GasReturn = big.NewInt(0)
+	GasStop   = big.NewInt(0)
+
+	GasContractByte = big.NewInt(200)
+
+	n64 = big.NewInt(64)
 )
 
 // calcGas returns the actual gas cost of the call.
 //
 // The cost of gas was changed during the homestead price change HF. To allow for EIP150
 // to be implemented. The returned gas is gas - base * 63 / 64.
-func callGas(gasTable params.GasTable, availableGas, base uint64, callCost *big.Int) (uint64, error) {
-	if gasTable.CreateBySuicide > 0 {
-		availableGas = availableGas - base
-		gas := availableGas - availableGas/64
-		// If the bit length exceeds 64 bit we know that the newly calculated "gas" for EIP150
-		// is smaller than the requested amount. Therefor we return the new gas instead
-		// of returning an error.
-		if callCost.BitLen() > 64 || gas < callCost.Uint64() {
-			return gas, nil
+func callGas(gasTable params.GasTable, availableGas, base, callCost *big.Int) *big.Int {
+	if gasTable.CreateBySuicide != nil {
+		availableGas = new(big.Int).Sub(availableGas, base)
+		g := new(big.Int).Div(availableGas, n64)
+		g.Sub(availableGas, g)
+
+		if g.Cmp(callCost) < 0 {
+			return g
 		}
 	}
-	if callCost.BitLen() > 64 {
-		return 0, errGasUintOverflow
+	return callCost
+}
+
+// baseCheck checks for any stack error underflows
+func baseCheck(op OpCode, stack *Stack, gas *big.Int) error {
+	// PUSH and DUP are a bit special. They all cost the same but we do want to have checking on stack push limit
+	// PUSH is also allowed to calculate the same price for all PUSHes
+	// DUP requirements are handled elsewhere (except for the stack limit check)
+	if op >= PUSH1 && op <= PUSH32 {
+		op = PUSH1
+	}
+	if op >= DUP1 && op <= DUP16 {
+		op = DUP1
+	}
+
+	if r, ok := _baseCheck[op]; ok {
+		err := stack.require(r.stackPop)
+		if err != nil {
+			return err
+		}
+
+		if r.stackPush > 0 && stack.len()-r.stackPop+r.stackPush > int(params.StackLimit.Int64()) {
+			return fmt.Errorf("stack limit reached %d (%d)", stack.len(), params.StackLimit.Int64())
+		}
+
+		gas.Add(gas, r.gas)
 	}
+	return nil
+}
+
+// casts a arbitrary number to the amount of words (sets of 32 bytes)
+func toWordSize(size *big.Int) *big.Int {
+	tmp := new(big.Int)
+	tmp.Add(size, u256(31))
+	tmp.Div(tmp, u256(32))
+	return tmp
+}
+
+type req struct {
+	stackPop  int
+	gas       *big.Int
+	stackPush int
+}
 
-	return callCost.Uint64(), nil
+var _baseCheck = map[OpCode]req{
+	// opcode  |  stack pop | gas price | stack push
+	ADD:          {2, GasFastestStep, 1},
+	LT:           {2, GasFastestStep, 1},
+	GT:           {2, GasFastestStep, 1},
+	SLT:          {2, GasFastestStep, 1},
+	SGT:          {2, GasFastestStep, 1},
+	EQ:           {2, GasFastestStep, 1},
+	ISZERO:       {1, GasFastestStep, 1},
+	SUB:          {2, GasFastestStep, 1},
+	AND:          {2, GasFastestStep, 1},
+	OR:           {2, GasFastestStep, 1},
+	XOR:          {2, GasFastestStep, 1},
+	NOT:          {1, GasFastestStep, 1},
+	BYTE:         {2, GasFastestStep, 1},
+	CALLDATALOAD: {1, GasFastestStep, 1},
+	CALLDATACOPY: {3, GasFastestStep, 1},
+	MLOAD:        {1, GasFastestStep, 1},
+	MSTORE:       {2, GasFastestStep, 0},
+	MSTORE8:      {2, GasFastestStep, 0},
+	CODECOPY:     {3, GasFastestStep, 0},
+	MUL:          {2, GasFastStep, 1},
+	DIV:          {2, GasFastStep, 1},
+	SDIV:         {2, GasFastStep, 1},
+	MOD:          {2, GasFastStep, 1},
+	SMOD:         {2, GasFastStep, 1},
+	SIGNEXTEND:   {2, GasFastStep, 1},
+	ADDMOD:       {3, GasMidStep, 1},
+	MULMOD:       {3, GasMidStep, 1},
+	JUMP:         {1, GasMidStep, 0},
+	JUMPI:        {2, GasSlowStep, 0},
+	EXP:          {2, GasSlowStep, 1},
+	ADDRESS:      {0, GasQuickStep, 1},
+	ORIGIN:       {0, GasQuickStep, 1},
+	CALLER:       {0, GasQuickStep, 1},
+	CALLVALUE:    {0, GasQuickStep, 1},
+	CODESIZE:     {0, GasQuickStep, 1},
+	GASPRICE:     {0, GasQuickStep, 1},
+	COINBASE:     {0, GasQuickStep, 1},
+	TIMESTAMP:    {0, GasQuickStep, 1},
+	NUMBER:       {0, GasQuickStep, 1},
+	CALLDATASIZE: {0, GasQuickStep, 1},
+	DIFFICULTY:   {0, GasQuickStep, 1},
+	GASLIMIT:     {0, GasQuickStep, 1},
+	POP:          {1, GasQuickStep, 0},
+	PC:           {0, GasQuickStep, 1},
+	MSIZE:        {0, GasQuickStep, 1},
+	GAS:          {0, GasQuickStep, 1},
+	BLOCKHASH:    {1, GasExtStep, 1},
+	BALANCE:      {1, Zero, 1},
+	EXTCODESIZE:  {1, Zero, 1},
+	EXTCODECOPY:  {4, Zero, 0},
+	SLOAD:        {1, params.SloadGas, 1},
+	SSTORE:       {2, Zero, 0},
+	SHA3:         {2, params.Sha3Gas, 1},
+	CREATE:       {3, params.CreateGas, 1},
+	// Zero is calculated in the gasSwitch
+	CALL:         {7, Zero, 1},
+	CALLCODE:     {7, Zero, 1},
+	DELEGATECALL: {6, Zero, 1},
+	SELFDESTRUCT: {1, Zero, 0},
+	JUMPDEST:     {0, params.JumpdestGas, 0},
+	RETURN:       {2, Zero, 0},
+	PUSH1:        {0, GasFastestStep, 1},
+	DUP1:         {0, Zero, 1},
 }
diff --git a/core/vm/gas_table.go b/core/vm/gas_table.go
index fba1eb066..4d2c4e94a 100644
--- a/core/vm/gas_table.go
+++ b/core/vm/gas_table.go
@@ -1,80 +1,56 @@
 package vm
 
 import (
-	gmath "math"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/params"
 )
 
-// memoryGasCosts calculates the quadratic gas for memory expansion. It does so
-// only for the memory region that is expanded, not the total memory.
-func memoryGasCost(mem *Memory, newMemSize uint64) (uint64, error) {
-	// The maximum that will fit in a uint64 is max_word_count - 1
-	// anything above that will result in an overflow.
-	if newMemSize > gmath.MaxUint64-32 {
-		return 0, errGasUintOverflow
-	}
-
-	if newMemSize == 0 {
-		return 0, nil
-	}
-
-	newMemSizeWords := toWordSize(newMemSize)
-	newMemSize = newMemSizeWords * 32
-
-	if newMemSize > uint64(mem.Len()) {
-		square := newMemSizeWords * newMemSizeWords
-		linCoef := newMemSizeWords * params.MemoryGas
-		quadCoef := square / params.QuadCoeffDiv
-		newTotalFee := linCoef + quadCoef
-
-		fee := newTotalFee - mem.lastGasCost
-		mem.lastGasCost = newTotalFee
-
-		return fee, nil
+func memoryGasCost(mem *Memory, newMemSize *big.Int) *big.Int {
+	gas := new(big.Int)
+	if newMemSize.Cmp(common.Big0) > 0 {
+		newMemSizeWords := toWordSize(newMemSize)
+
+		if newMemSize.Cmp(u256(int64(mem.Len()))) > 0 {
+			// be careful reusing variables here when changing.
+			// The order has been optimised to reduce allocation
+			oldSize := toWordSize(big.NewInt(int64(mem.Len())))
+			pow := new(big.Int).Exp(oldSize, common.Big2, Zero)
+			linCoef := oldSize.Mul(oldSize, params.MemoryGas)
+			quadCoef := new(big.Int).Div(pow, params.QuadCoeffDiv)
+			oldTotalFee := new(big.Int).Add(linCoef, quadCoef)
+
+			pow.Exp(newMemSizeWords, common.Big2, Zero)
+			linCoef = linCoef.Mul(newMemSizeWords, params.MemoryGas)
+			quadCoef = quadCoef.Div(pow, params.QuadCoeffDiv)
+			newTotalFee := linCoef.Add(linCoef, quadCoef)
+
+			fee := newTotalFee.Sub(newTotalFee, oldTotalFee)
+			gas.Add(gas, fee)
+		}
 	}
-	return 0, nil
+	return gas
 }
 
-func constGasFunc(gas uint64) gasFunc {
-	return func(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-		return gas, nil
+func constGasFunc(gas *big.Int) gasFunc {
+	return func(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+		return gas
 	}
 }
 
-func gasCalldataCopy(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-
-	var overflow bool
-	if gas, overflow = math.SafeAdd(gas, GasFastestStep); overflow {
-		return 0, errGasUintOverflow
-	}
+func gasCalldataCopy(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, GasFastestStep)
+	words := toWordSize(stack.Back(2))
 
-	words, overflow := bigUint64(stack.Back(2))
-	if overflow {
-		return 0, errGasUintOverflow
-	}
-
-	if words, overflow = math.SafeMul(toWordSize(words), params.CopyGas); overflow {
-		return 0, errGasUintOverflow
-	}
-
-	if gas, overflow = math.SafeAdd(gas, words); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+	return gas.Add(gas, words.Mul(words, params.CopyGas))
 }
 
-func gasSStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+func gasSStore(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
 	var (
 		y, x = stack.Back(1), stack.Back(0)
-		val  = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
+		val  = env.StateDB.GetState(contract.Address(), common.BigToHash(x))
 	)
 	// This checks for 3 scenario's and calculates gas accordingly
 	// 1. From a zero-value address to a non-zero value         (NEW VALUE)
@@ -82,335 +58,189 @@ func gasSStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, m
 	// 3. From a non-zero to a non-zero                         (CHANGE)
 	if common.EmptyHash(val) && !common.EmptyHash(common.BigToHash(y)) {
 		// 0 => non 0
-		return params.SstoreSetGas, nil
+		return new(big.Int).Set(params.SstoreSetGas)
 	} else if !common.EmptyHash(val) && common.EmptyHash(common.BigToHash(y)) {
-		evm.StateDB.AddRefund(new(big.Int).SetUint64(params.SstoreRefundGas))
+		env.StateDB.AddRefund(params.SstoreRefundGas)
 
-		return params.SstoreClearGas, nil
+		return new(big.Int).Set(params.SstoreClearGas)
 	} else {
 		// non 0 => non 0 (or 0 => 0)
-		return params.SstoreResetGas, nil
+		return new(big.Int).Set(params.SstoreResetGas)
 	}
 }
 
-func makeGasLog(n uint64) gasFunc {
-	return func(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-		requestedSize, overflow := bigUint64(stack.Back(1))
-		if overflow {
-			return 0, errGasUintOverflow
-		}
+func makeGasLog(n uint) gasFunc {
+	return func(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+		mSize := stack.Back(1)
 
-		gas, err := memoryGasCost(mem, memorySize)
-		if err != nil {
-			return 0, err
-		}
-
-		if gas, overflow = math.SafeAdd(gas, params.LogGas); overflow {
-			return 0, errGasUintOverflow
-		}
-		if gas, overflow = math.SafeAdd(gas, n*params.LogTopicGas); overflow {
-			return 0, errGasUintOverflow
-		}
-
-		var memorySizeGas uint64
-		if memorySizeGas, overflow = math.SafeMul(requestedSize, params.LogDataGas); overflow {
-			return 0, errGasUintOverflow
-		}
-		if gas, overflow = math.SafeAdd(gas, memorySizeGas); overflow {
-			return 0, errGasUintOverflow
-		}
-		return gas, nil
+		gas := new(big.Int).Add(memoryGasCost(mem, memorySize), params.LogGas)
+		gas.Add(gas, new(big.Int).Mul(big.NewInt(int64(n)), params.LogTopicGas))
+		gas.Add(gas, new(big.Int).Mul(mSize, params.LogDataGas))
+		return gas
 	}
 }
 
-func gasSha3(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	var overflow bool
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-
-	if gas, overflow = math.SafeAdd(gas, params.Sha3Gas); overflow {
-		return 0, errGasUintOverflow
-	}
-
-	wordGas, overflow := bigUint64(stack.Back(1))
-	if overflow {
-		return 0, errGasUintOverflow
-	}
-	if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.Sha3WordGas); overflow {
-		return 0, errGasUintOverflow
-	}
-	if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+func gasSha3(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, params.Sha3Gas)
+	words := toWordSize(stack.Back(1))
+	return gas.Add(gas, words.Mul(words, params.Sha3WordGas))
 }
 
-func gasCodeCopy(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-
-	var overflow bool
-	if gas, overflow = math.SafeAdd(gas, GasFastestStep); overflow {
-		return 0, errGasUintOverflow
-	}
+func gasCodeCopy(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, GasFastestStep)
+	words := toWordSize(stack.Back(2))
 
-	wordGas, overflow := bigUint64(stack.Back(2))
-	if overflow {
-		return 0, errGasUintOverflow
-	}
-	if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.CopyGas); overflow {
-		return 0, errGasUintOverflow
-	}
-	if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+	return gas.Add(gas, words.Mul(words, params.CopyGas))
 }
 
-func gasExtCodeCopy(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-
-	var overflow bool
-	if gas, overflow = math.SafeAdd(gas, gt.ExtcodeCopy); overflow {
-		return 0, errGasUintOverflow
-	}
-
-	wordGas, overflow := bigUint64(stack.Back(3))
-	if overflow {
-		return 0, errGasUintOverflow
-	}
-
-	if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.CopyGas); overflow {
-		return 0, errGasUintOverflow
-	}
+func gasExtCodeCopy(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := memoryGasCost(mem, memorySize)
+	gas.Add(gas, gt.ExtcodeCopy)
+	words := toWordSize(stack.Back(3))
 
-	if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+	return gas.Add(gas, words.Mul(words, params.CopyGas))
 }
 
-func gasMLoad(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	var overflow bool
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, errGasUintOverflow
-	}
-	if gas, overflow = math.SafeAdd(gas, GasFastestStep); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+func gasMLoad(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(GasFastestStep, memoryGasCost(mem, memorySize))
 }
 
-func gasMStore8(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	var overflow bool
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, errGasUintOverflow
-	}
-	if gas, overflow = math.SafeAdd(gas, GasFastestStep); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+func gasMStore8(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(GasFastestStep, memoryGasCost(mem, memorySize))
 }
 
-func gasMStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	var overflow bool
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, errGasUintOverflow
-	}
-	if gas, overflow = math.SafeAdd(gas, GasFastestStep); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+func gasMStore(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(GasFastestStep, memoryGasCost(mem, memorySize))
 }
 
-func gasCreate(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	var overflow bool
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-	if gas, overflow = math.SafeAdd(gas, params.CreateGas); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+func gasCreate(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return new(big.Int).Add(params.CreateGas, memoryGasCost(mem, memorySize))
 }
 
-func gasBalance(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	return gt.Balance, nil
+func gasBalance(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return gt.Balance
 }
 
-func gasExtCodeSize(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	return gt.ExtcodeSize, nil
+func gasExtCodeSize(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return gt.ExtcodeSize
 }
 
-func gasSLoad(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	return gt.SLoad, nil
+func gasSLoad(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return gt.SLoad
 }
 
-func gasExp(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	expByteLen := uint64((stack.data[stack.len()-2].BitLen() + 7) / 8)
-
-	var (
-		gas      = expByteLen * gt.ExpByte // no overflow check required. Max is 256 * ExpByte gas
-		overflow bool
-	)
-	if gas, overflow = math.SafeAdd(gas, GasSlowStep); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+func gasExp(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	expByteLen := int64((stack.data[stack.len()-2].BitLen() + 7) / 8)
+	gas := big.NewInt(expByteLen)
+	gas.Mul(gas, gt.ExpByte)
+	return gas.Add(gas, GasSlowStep)
 }
 
-func gasCall(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+func gasCall(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int).Set(gt.Calls)
+
+	transfersValue := stack.Back(2).BitLen() > 0
 	var (
-		gas            = gt.Calls
-		transfersValue = stack.Back(2).BitLen() > 0
-		address        = common.BigToAddress(stack.Back(1))
-		eip158         = evm.ChainConfig().IsEIP158(evm.BlockNumber)
+		address = common.BigToAddress(stack.Back(1))
+		eip158  = env.ChainConfig().IsEIP158(env.BlockNumber)
 	)
 	if eip158 {
-		if evm.StateDB.Empty(address) && transfersValue {
-			gas += params.CallNewAccountGas
+		if env.StateDB.Empty(address) && transfersValue {
+			gas.Add(gas, params.CallNewAccountGas)
 		}
-	} else if !evm.StateDB.Exist(address) {
-		gas += params.CallNewAccountGas
+	} else if !env.StateDB.Exist(address) {
+		gas.Add(gas, params.CallNewAccountGas)
 	}
 	if transfersValue {
-		gas += params.CallValueTransferGas
-	}
-	memoryGas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-	var overflow bool
-	if gas, overflow = math.SafeAdd(gas, memoryGas); overflow {
-		return 0, errGasUintOverflow
+		gas.Add(gas, params.CallValueTransferGas)
 	}
+	gas.Add(gas, memoryGasCost(mem, memorySize))
 
-	cg, err := callGas(gt, contract.Gas, gas, stack.Back(0))
-	if err != nil {
-		return 0, err
-	}
+	cg := callGas(gt, contract.Gas, gas, stack.data[stack.len()-1])
 	// Replace the stack item with the new gas calculation. This means that
 	// either the original item is left on the stack or the item is replaced by:
 	// (availableGas - gas) * 63 / 64
 	// We replace the stack item so that it's available when the opCall instruction is
 	// called. This information is otherwise lost due to the dependency on *current*
 	// available gas.
-	stack.data[stack.len()-1] = new(big.Int).SetUint64(cg)
+	stack.data[stack.len()-1] = cg
 
-	if gas, overflow = math.SafeAdd(gas, cg); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+	return gas.Add(gas, cg)
 }
 
-func gasCallCode(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	gas := gt.Calls
+func gasCallCode(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int).Set(gt.Calls)
 	if stack.Back(2).BitLen() > 0 {
-		gas += params.CallValueTransferGas
-	}
-	memoryGas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-	var overflow bool
-	if gas, overflow = math.SafeAdd(gas, memoryGas); overflow {
-		return 0, errGasUintOverflow
+		gas.Add(gas, params.CallValueTransferGas)
 	}
+	gas.Add(gas, memoryGasCost(mem, memorySize))
 
-	cg, err := callGas(gt, contract.Gas, gas, stack.Back(0))
-	if err != nil {
-		return 0, err
-	}
+	cg := callGas(gt, contract.Gas, gas, stack.data[stack.len()-1])
 	// Replace the stack item with the new gas calculation. This means that
 	// either the original item is left on the stack or the item is replaced by:
 	// (availableGas - gas) * 63 / 64
 	// We replace the stack item so that it's available when the opCall instruction is
 	// called. This information is otherwise lost due to the dependency on *current*
 	// available gas.
-	stack.data[stack.len()-1] = new(big.Int).SetUint64(cg)
+	stack.data[stack.len()-1] = cg
 
-	if gas, overflow = math.SafeAdd(gas, cg); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+	return gas.Add(gas, cg)
 }
 
-func gasReturn(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
+func gasReturn(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
 	return memoryGasCost(mem, memorySize)
 }
 
-func gasSuicide(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	var gas uint64
+func gasSuicide(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int)
 	// EIP150 homestead gas reprice fork:
-	if evm.ChainConfig().IsEIP150(evm.BlockNumber) {
-		gas = gt.Suicide
+	if env.ChainConfig().IsEIP150(env.BlockNumber) {
+		gas.Set(gt.Suicide)
 		var (
 			address = common.BigToAddress(stack.Back(0))
-			eip158  = evm.ChainConfig().IsEIP158(evm.BlockNumber)
+			eip158  = env.ChainConfig().IsEIP158(env.BlockNumber)
 		)
 
 		if eip158 {
 			// if empty and transfers value
-			if evm.StateDB.Empty(address) && evm.StateDB.GetBalance(contract.Address()).BitLen() > 0 {
-				gas += gt.CreateBySuicide
+			if env.StateDB.Empty(address) && env.StateDB.GetBalance(contract.Address()).BitLen() > 0 {
+				gas.Add(gas, gt.CreateBySuicide)
 			}
-		} else if !evm.StateDB.Exist(address) {
-			gas += gt.CreateBySuicide
+		} else if !env.StateDB.Exist(address) {
+			gas.Add(gas, gt.CreateBySuicide)
 		}
 	}
 
-	if !evm.StateDB.HasSuicided(contract.Address()) {
-		evm.StateDB.AddRefund(new(big.Int).SetUint64(params.SuicideRefundGas))
+	if !env.StateDB.HasSuicided(contract.Address()) {
+		env.StateDB.AddRefund(params.SuicideRefundGas)
 	}
-	return gas, nil
+	return gas
 }
 
-func gasDelegateCall(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	gas, err := memoryGasCost(mem, memorySize)
-	if err != nil {
-		return 0, err
-	}
-	var overflow bool
-	if gas, overflow = math.SafeAdd(gas, gt.Calls); overflow {
-		return 0, errGasUintOverflow
-	}
+func gasDelegateCall(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	gas := new(big.Int).Add(gt.Calls, memoryGasCost(mem, memorySize))
 
-	cg, err := callGas(gt, contract.Gas, gas, stack.Back(0))
-	if err != nil {
-		return 0, err
-	}
+	cg := callGas(gt, contract.Gas, gas, stack.data[stack.len()-1])
 	// Replace the stack item with the new gas calculation. This means that
 	// either the original item is left on the stack or the item is replaced by:
 	// (availableGas - gas) * 63 / 64
 	// We replace the stack item so that it's available when the opCall instruction is
 	// called.
-	stack.data[stack.len()-1] = new(big.Int).SetUint64(cg)
+	stack.data[stack.len()-1] = cg
 
-	if gas, overflow = math.SafeAdd(gas, cg); overflow {
-		return 0, errGasUintOverflow
-	}
-	return gas, nil
+	return gas.Add(gas, cg)
 }
 
-func gasPush(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	return GasFastestStep, nil
+func gasPush(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return GasFastestStep
 }
 
-func gasSwap(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	return GasFastestStep, nil
+func gasSwap(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return GasFastestStep
 }
 
-func gasDup(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-	return GasFastestStep, nil
+func gasDup(gt params.GasTable, env *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize *big.Int) *big.Int {
+	return GasFastestStep
 }
diff --git a/core/vm/gas_table_test.go b/core/vm/gas_table_test.go
deleted file mode 100644
index cceb89285..000000000
--- a/core/vm/gas_table_test.go
+++ /dev/null
@@ -1,24 +0,0 @@
-package vm
-
-import (
-	"math"
-	"testing"
-)
-
-func TestMemoryGasCost(t *testing.T) {
-	size := uint64(math.MaxUint64 - 64)
-	_, err := memoryGasCost(&Memory{}, size)
-	if err != nil {
-		t.Error("didn't expect error:", err)
-	}
-
-	_, err = memoryGasCost(&Memory{}, size+32)
-	if err != nil {
-		t.Error("didn't expect error:", err)
-	}
-
-	_, err = memoryGasCost(&Memory{}, size+33)
-	if err == nil {
-		t.Error("expected error")
-	}
-}
diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index 39e5c0587..3b1b06cca 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -27,56 +27,42 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 )
 
-var bigZero = new(big.Int)
-
-func opAdd(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opAdd(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	stack.push(U256(x.Add(x, y)))
-
-	evm.interpreter.intPool.put(y)
-
 	return nil, nil
 }
 
-func opSub(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSub(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	stack.push(U256(x.Sub(x, y)))
-
-	evm.interpreter.intPool.put(y)
-
 	return nil, nil
 }
 
-func opMul(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opMul(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	stack.push(U256(x.Mul(x, y)))
-
-	evm.interpreter.intPool.put(y)
-
 	return nil, nil
 }
 
-func opDiv(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opDiv(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	if y.Cmp(common.Big0) != 0 {
 		stack.push(U256(x.Div(x, y)))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(y)
-
 	return nil, nil
 }
 
-func opSdiv(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSdiv(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := S256(stack.pop()), S256(stack.pop())
 	if y.Cmp(common.Big0) == 0 {
 		stack.push(new(big.Int))
 		return nil, nil
 	} else {
 		n := new(big.Int)
-		if evm.interpreter.intPool.get().Mul(x, y).Cmp(common.Big0) < 0 {
+		if new(big.Int).Mul(x, y).Cmp(common.Big0) < 0 {
 			n.SetInt64(-1)
 		} else {
 			n.SetInt64(1)
@@ -87,22 +73,20 @@ func opSdiv(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Sta
 
 		stack.push(U256(res))
 	}
-	evm.interpreter.intPool.put(y)
 	return nil, nil
 }
 
-func opMod(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opMod(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	if y.Cmp(common.Big0) == 0 {
 		stack.push(new(big.Int))
 	} else {
 		stack.push(U256(x.Mod(x, y)))
 	}
-	evm.interpreter.intPool.put(y)
 	return nil, nil
 }
 
-func opSmod(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSmod(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := S256(stack.pop()), S256(stack.pop())
 
 	if y.Cmp(common.Big0) == 0 {
@@ -120,20 +104,16 @@ func opSmod(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Sta
 
 		stack.push(U256(res))
 	}
-	evm.interpreter.intPool.put(y)
 	return nil, nil
 }
 
-func opExp(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opExp(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	base, exponent := stack.pop(), stack.pop()
 	stack.push(math.Exp(base, exponent))
-
-	evm.interpreter.intPool.put(base, exponent)
-
 	return nil, nil
 }
 
-func opSignExtend(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSignExtend(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	back := stack.pop()
 	if back.Cmp(big.NewInt(31)) < 0 {
 		bit := uint(back.Uint64()*8 + 7)
@@ -148,231 +128,198 @@ func opSignExtend(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stac
 
 		stack.push(U256(num))
 	}
-
-	evm.interpreter.intPool.put(back)
 	return nil, nil
 }
 
-func opNot(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opNot(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x := stack.pop()
 	stack.push(U256(x.Not(x)))
 	return nil, nil
 }
 
-func opLt(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opLt(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	if x.Cmp(y) < 0 {
-		stack.push(evm.interpreter.intPool.get().SetUint64(1))
+		stack.push(big.NewInt(1))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(x, y)
 	return nil, nil
 }
 
-func opGt(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opGt(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	if x.Cmp(y) > 0 {
-		stack.push(evm.interpreter.intPool.get().SetUint64(1))
+		stack.push(big.NewInt(1))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(x, y)
 	return nil, nil
 }
 
-func opSlt(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSlt(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := S256(stack.pop()), S256(stack.pop())
 	if x.Cmp(S256(y)) < 0 {
-		stack.push(evm.interpreter.intPool.get().SetUint64(1))
+		stack.push(big.NewInt(1))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(x, y)
 	return nil, nil
 }
 
-func opSgt(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSgt(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := S256(stack.pop()), S256(stack.pop())
 	if x.Cmp(y) > 0 {
-		stack.push(evm.interpreter.intPool.get().SetUint64(1))
+		stack.push(big.NewInt(1))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(x, y)
 	return nil, nil
 }
 
-func opEq(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opEq(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	if x.Cmp(y) == 0 {
-		stack.push(evm.interpreter.intPool.get().SetUint64(1))
+		stack.push(big.NewInt(1))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(x, y)
 	return nil, nil
 }
 
-func opIszero(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opIszero(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x := stack.pop()
 	if x.Cmp(common.Big0) > 0 {
 		stack.push(new(big.Int))
 	} else {
-		stack.push(evm.interpreter.intPool.get().SetUint64(1))
+		stack.push(big.NewInt(1))
 	}
-
-	evm.interpreter.intPool.put(x)
 	return nil, nil
 }
 
-func opAnd(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opAnd(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	stack.push(x.And(x, y))
-
-	evm.interpreter.intPool.put(y)
 	return nil, nil
 }
-func opOr(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opOr(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	stack.push(x.Or(x, y))
-
-	evm.interpreter.intPool.put(y)
 	return nil, nil
 }
-func opXor(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opXor(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y := stack.pop(), stack.pop()
 	stack.push(x.Xor(x, y))
-
-	evm.interpreter.intPool.put(y)
 	return nil, nil
 }
-func opByte(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opByte(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	th, val := stack.pop(), stack.pop()
 	if th.Cmp(big.NewInt(32)) < 0 {
-		byte := evm.interpreter.intPool.get().SetInt64(int64(common.LeftPadBytes(val.Bytes(), 32)[th.Int64()]))
+		byte := big.NewInt(int64(common.LeftPadBytes(val.Bytes(), 32)[th.Int64()]))
 		stack.push(byte)
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(th, val)
 	return nil, nil
 }
-func opAddmod(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opAddmod(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y, z := stack.pop(), stack.pop(), stack.pop()
-	if z.Cmp(bigZero) > 0 {
+	if z.Cmp(Zero) > 0 {
 		add := x.Add(x, y)
 		add.Mod(add, z)
 		stack.push(U256(add))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(y, z)
 	return nil, nil
 }
-func opMulmod(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opMulmod(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	x, y, z := stack.pop(), stack.pop(), stack.pop()
-	if z.Cmp(bigZero) > 0 {
+	if z.Cmp(Zero) > 0 {
 		mul := x.Mul(x, y)
 		mul.Mod(mul, z)
 		stack.push(U256(mul))
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(y, z)
 	return nil, nil
 }
 
-func opSha3(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSha3(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	offset, size := stack.pop(), stack.pop()
 	data := memory.Get(offset.Int64(), size.Int64())
 	hash := crypto.Keccak256(data)
 
-	if evm.vmConfig.EnablePreimageRecording {
-		evm.StateDB.AddPreimage(common.BytesToHash(hash), data)
+	if env.vmConfig.EnablePreimageRecording {
+		env.StateDB.AddPreimage(common.BytesToHash(hash), data)
 	}
 
 	stack.push(common.BytesToBig(hash))
-
-	evm.interpreter.intPool.put(offset, size)
 	return nil, nil
 }
 
-func opAddress(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opAddress(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	stack.push(common.Bytes2Big(contract.Address().Bytes()))
 	return nil, nil
 }
 
-func opBalance(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opBalance(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	addr := common.BigToAddress(stack.pop())
-	balance := evm.StateDB.GetBalance(addr)
+	balance := env.StateDB.GetBalance(addr)
 
 	stack.push(new(big.Int).Set(balance))
 	return nil, nil
 }
 
-func opOrigin(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.Origin.Big())
+func opOrigin(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(env.Origin.Big())
 	return nil, nil
 }
 
-func opCaller(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opCaller(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	stack.push(contract.Caller().Big())
 	return nil, nil
 }
 
-func opCallValue(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.interpreter.intPool.get().Set(contract.value))
+func opCallValue(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(new(big.Int).Set(contract.value))
 	return nil, nil
 }
 
-func opCalldataLoad(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opCalldataLoad(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	stack.push(common.Bytes2Big(getData(contract.Input, stack.pop(), common.Big32)))
 	return nil, nil
 }
 
-func opCalldataSize(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.interpreter.intPool.get().SetInt64(int64(len(contract.Input))))
+func opCalldataSize(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(big.NewInt(int64(len(contract.Input))))
 	return nil, nil
 }
 
-func opCalldataCopy(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opCalldataCopy(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	var (
 		mOff = stack.pop()
 		cOff = stack.pop()
 		l    = stack.pop()
 	)
 	memory.Set(mOff.Uint64(), l.Uint64(), getData(contract.Input, cOff, l))
-
-	evm.interpreter.intPool.put(mOff, cOff, l)
 	return nil, nil
 }
 
-func opExtCodeSize(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	a := stack.pop()
-
-	addr := common.BigToAddress(a)
-	a.SetInt64(int64(evm.StateDB.GetCodeSize(addr)))
-	stack.push(a)
-
+func opExtCodeSize(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	addr := common.BigToAddress(stack.pop())
+	l := big.NewInt(int64(env.StateDB.GetCodeSize(addr)))
+	stack.push(l)
 	return nil, nil
 }
 
-func opCodeSize(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	l := evm.interpreter.intPool.get().SetInt64(int64(len(contract.Code)))
+func opCodeSize(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	l := big.NewInt(int64(len(contract.Code)))
 	stack.push(l)
 	return nil, nil
 }
 
-func opCodeCopy(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opCodeCopy(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	var (
 		mOff = stack.pop()
 		cOff = stack.pop()
@@ -381,129 +328,113 @@ func opCodeCopy(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack
 	codeCopy := getData(contract.Code, cOff, l)
 
 	memory.Set(mOff.Uint64(), l.Uint64(), codeCopy)
-
-	evm.interpreter.intPool.put(mOff, cOff, l)
 	return nil, nil
 }
 
-func opExtCodeCopy(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opExtCodeCopy(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	var (
 		addr = common.BigToAddress(stack.pop())
 		mOff = stack.pop()
 		cOff = stack.pop()
 		l    = stack.pop()
 	)
-	codeCopy := getData(evm.StateDB.GetCode(addr), cOff, l)
+	codeCopy := getData(env.StateDB.GetCode(addr), cOff, l)
 
 	memory.Set(mOff.Uint64(), l.Uint64(), codeCopy)
-
-	evm.interpreter.intPool.put(mOff, cOff, l)
-
 	return nil, nil
 }
 
-func opGasprice(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.interpreter.intPool.get().Set(evm.GasPrice))
+func opGasprice(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(new(big.Int).Set(env.GasPrice))
 	return nil, nil
 }
 
-func opBlockhash(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opBlockhash(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	num := stack.pop()
 
-	n := evm.interpreter.intPool.get().Sub(evm.BlockNumber, common.Big257)
-	if num.Cmp(n) > 0 && num.Cmp(evm.BlockNumber) < 0 {
-		stack.push(evm.GetHash(num.Uint64()).Big())
+	n := new(big.Int).Sub(env.BlockNumber, common.Big257)
+	if num.Cmp(n) > 0 && num.Cmp(env.BlockNumber) < 0 {
+		stack.push(env.GetHash(num.Uint64()).Big())
 	} else {
 		stack.push(new(big.Int))
 	}
-
-	evm.interpreter.intPool.put(num, n)
 	return nil, nil
 }
 
-func opCoinbase(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.Coinbase.Big())
+func opCoinbase(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(env.Coinbase.Big())
 	return nil, nil
 }
 
-func opTimestamp(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(U256(new(big.Int).Set(evm.Time)))
+func opTimestamp(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(U256(new(big.Int).Set(env.Time)))
 	return nil, nil
 }
 
-func opNumber(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(U256(new(big.Int).Set(evm.BlockNumber)))
+func opNumber(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(U256(new(big.Int).Set(env.BlockNumber)))
 	return nil, nil
 }
 
-func opDifficulty(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(U256(new(big.Int).Set(evm.Difficulty)))
+func opDifficulty(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(U256(new(big.Int).Set(env.Difficulty)))
 	return nil, nil
 }
 
-func opGasLimit(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(U256(new(big.Int).Set(evm.GasLimit)))
+func opGasLimit(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(U256(new(big.Int).Set(env.GasLimit)))
 	return nil, nil
 }
 
-func opPop(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	evm.interpreter.intPool.put(stack.pop())
+func opPop(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.pop()
 	return nil, nil
 }
 
-func opMload(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opMload(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	offset := stack.pop()
 	val := common.BigD(memory.Get(offset.Int64(), 32))
 	stack.push(val)
-
-	evm.interpreter.intPool.put(offset)
 	return nil, nil
 }
 
-func opMstore(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opMstore(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	// pop value of the stack
 	mStart, val := stack.pop(), stack.pop()
 	memory.Set(mStart.Uint64(), 32, common.BigToBytes(val, 256))
-
-	evm.interpreter.intPool.put(mStart, val)
 	return nil, nil
 }
 
-func opMstore8(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opMstore8(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	off, val := stack.pop().Int64(), stack.pop().Int64()
 	memory.store[off] = byte(val & 0xff)
-
 	return nil, nil
 }
 
-func opSload(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSload(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	loc := common.BigToHash(stack.pop())
-	val := evm.StateDB.GetState(contract.Address(), loc).Big()
+	val := env.StateDB.GetState(contract.Address(), loc).Big()
 	stack.push(val)
 	return nil, nil
 }
 
-func opSstore(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opSstore(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	loc := common.BigToHash(stack.pop())
 	val := stack.pop()
-	evm.StateDB.SetState(contract.Address(), loc, common.BigToHash(val))
-
-	evm.interpreter.intPool.put(val)
+	env.StateDB.SetState(contract.Address(), loc, common.BigToHash(val))
 	return nil, nil
 }
 
-func opJump(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opJump(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	pos := stack.pop()
 	if !contract.jumpdests.has(contract.CodeHash, contract.Code, pos) {
 		nop := contract.GetOp(pos.Uint64())
 		return nil, fmt.Errorf("invalid jump destination (%v) %v", nop, pos)
 	}
 	*pc = pos.Uint64()
-
-	evm.interpreter.intPool.put(pos)
 	return nil, nil
 }
-func opJumpi(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opJumpi(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	pos, cond := stack.pop(), stack.pop()
 	if cond.Cmp(common.BigTrue) >= 0 {
 		if !contract.jumpdests.has(contract.CodeHash, contract.Code, pos) {
@@ -514,62 +445,57 @@ func opJumpi(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *St
 	} else {
 		*pc++
 	}
-
-	evm.interpreter.intPool.put(pos, cond)
 	return nil, nil
 }
-func opJumpdest(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opJumpdest(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	return nil, nil
 }
 
-func opPc(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.interpreter.intPool.get().SetUint64(*pc))
+func opPc(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(new(big.Int).SetUint64(*pc))
 	return nil, nil
 }
 
-func opMsize(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.interpreter.intPool.get().SetInt64(int64(memory.Len())))
+func opMsize(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(big.NewInt(int64(memory.Len())))
 	return nil, nil
 }
 
-func opGas(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	stack.push(evm.interpreter.intPool.get().SetUint64(contract.Gas))
+func opGas(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	stack.push(new(big.Int).Set(contract.Gas))
 	return nil, nil
 }
 
-func opCreate(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opCreate(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	var (
 		value        = stack.pop()
 		offset, size = stack.pop(), stack.pop()
 		input        = memory.Get(offset.Int64(), size.Int64())
-		gas          = contract.Gas
+		gas          = new(big.Int).Set(contract.Gas)
 	)
-	if evm.ChainConfig().IsEIP150(evm.BlockNumber) {
-		gas -= gas / 64
+	if env.ChainConfig().IsEIP150(env.BlockNumber) {
+		gas.Div(gas, n64)
+		gas = gas.Sub(contract.Gas, gas)
 	}
 
 	contract.UseGas(gas)
-	_, addr, returnGas, suberr := evm.Create(contract, input, gas, value)
+	_, addr, suberr := env.Create(contract, input, gas, value)
 	// Push item on the stack based on the returned error. If the ruleset is
 	// homestead we must check for CodeStoreOutOfGasError (homestead only
 	// rule) and treat as an error, if the ruleset is frontier we must
 	// ignore this error and pretend the operation was successful.
-	if evm.ChainConfig().IsHomestead(evm.BlockNumber) && suberr == ErrCodeStoreOutOfGas {
+	if env.ChainConfig().IsHomestead(env.BlockNumber) && suberr == ErrCodeStoreOutOfGas {
 		stack.push(new(big.Int))
 	} else if suberr != nil && suberr != ErrCodeStoreOutOfGas {
 		stack.push(new(big.Int))
 	} else {
 		stack.push(addr.Big())
 	}
-	contract.Gas += returnGas
-
-	evm.interpreter.intPool.put(value, offset, size)
-
 	return nil, nil
 }
 
-func opCall(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	gas := stack.pop().Uint64()
+func opCall(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	gas := stack.pop()
 	// pop gas and value of the stack.
 	addr, value := stack.pop(), stack.pop()
 	value = U256(value)
@@ -583,26 +509,25 @@ func opCall(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Sta
 	// Get the arguments from the memory
 	args := memory.Get(inOffset.Int64(), inSize.Int64())
 
-	if value.BitLen() > 0 {
-		gas += params.CallStipend
+	if len(value.Bytes()) > 0 {
+		gas.Add(gas, params.CallStipend)
 	}
 
-	ret, returnGas, err := evm.Call(contract, address, args, gas, value)
+	ret, err := env.Call(contract, address, args, gas, value)
+
 	if err != nil {
 		stack.push(new(big.Int))
+
 	} else {
 		stack.push(big.NewInt(1))
 
 		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
-	contract.Gas += returnGas
-
-	evm.interpreter.intPool.put(addr, value, inOffset, inSize, retOffset, retSize)
 	return nil, nil
 }
 
-func opCallCode(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	gas := stack.pop().Uint64()
+func opCallCode(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	gas := stack.pop()
 	// pop gas and value of the stack.
 	addr, value := stack.pop(), stack.pop()
 	value = U256(value)
@@ -616,11 +541,12 @@ func opCallCode(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack
 	// Get the arguments from the memory
 	args := memory.Get(inOffset.Int64(), inSize.Int64())
 
-	if value.BitLen() > 0 {
-		gas += params.CallStipend
+	if len(value.Bytes()) > 0 {
+		gas.Add(gas, params.CallStipend)
 	}
 
-	ret, returnGas, err := evm.CallCode(contract, address, args, gas, value)
+	ret, err := env.CallCode(contract, address, args, gas, value)
+
 	if err != nil {
 		stack.push(new(big.Int))
 
@@ -629,54 +555,46 @@ func opCallCode(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack
 
 		memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
 	}
-	contract.Gas += returnGas
-
-	evm.interpreter.intPool.put(addr, value, inOffset, inSize, retOffset, retSize)
 	return nil, nil
 }
 
-func opDelegateCall(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opDelegateCall(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	// if not homestead return an error. DELEGATECALL is not supported
 	// during pre-homestead.
-	if !evm.ChainConfig().IsHomestead(evm.BlockNumber) {
+	if !env.ChainConfig().IsHomestead(env.BlockNumber) {
 		return nil, fmt.Errorf("invalid opcode %x", DELEGATECALL)
 	}
 
-	gas, to, inOffset, inSize, outOffset, outSize := stack.pop().Uint64(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
+	gas, to, inOffset, inSize, outOffset, outSize := stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop(), stack.pop()
 
 	toAddr := common.BigToAddress(to)
 	args := memory.Get(inOffset.Int64(), inSize.Int64())
-
-	ret, returnGas, err := evm.DelegateCall(contract, toAddr, args, gas)
+	ret, err := env.DelegateCall(contract, toAddr, args, gas)
 	if err != nil {
 		stack.push(new(big.Int))
 	} else {
 		stack.push(big.NewInt(1))
 		memory.Set(outOffset.Uint64(), outSize.Uint64(), ret)
 	}
-	contract.Gas += returnGas
-
-	evm.interpreter.intPool.put(to, inOffset, inSize, outOffset, outSize)
 	return nil, nil
 }
 
-func opReturn(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opReturn(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	offset, size := stack.pop(), stack.pop()
 	ret := memory.GetPtr(offset.Int64(), size.Int64())
 
-	evm.interpreter.intPool.put(offset, size)
 	return ret, nil
 }
 
-func opStop(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+func opStop(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 	return nil, nil
 }
 
-func opSuicide(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-	balance := evm.StateDB.GetBalance(contract.Address())
-	evm.StateDB.AddBalance(common.BigToAddress(stack.pop()), balance)
+func opSuicide(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	balance := env.StateDB.GetBalance(contract.Address())
+	env.StateDB.AddBalance(common.BigToAddress(stack.pop()), balance)
 
-	evm.StateDB.Suicide(contract.Address())
+	env.StateDB.Suicide(contract.Address())
 
 	return nil, nil
 }
@@ -685,7 +603,7 @@ func opSuicide(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *
 
 // make log instruction function
 func makeLog(size int) executionFunc {
-	return func(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	return func(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 		topics := make([]common.Hash, size)
 		mStart, mSize := stack.pop(), stack.pop()
 		for i := 0; i < size; i++ {
@@ -693,24 +611,22 @@ func makeLog(size int) executionFunc {
 		}
 
 		d := memory.Get(mStart.Int64(), mSize.Int64())
-		evm.StateDB.AddLog(&types.Log{
+		env.StateDB.AddLog(&types.Log{
 			Address: contract.Address(),
 			Topics:  topics,
 			Data:    d,
 			// This is a non-consensus field, but assigned here because
 			// core/state doesn't know the current block number.
-			BlockNumber: evm.BlockNumber.Uint64(),
+			BlockNumber: env.BlockNumber.Uint64(),
 		})
-
-		evm.interpreter.intPool.put(mStart, mSize)
 		return nil, nil
 	}
 }
 
 // make push instruction function
 func makePush(size uint64, bsize *big.Int) executionFunc {
-	return func(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
-		byts := getData(contract.Code, evm.interpreter.intPool.get().SetUint64(*pc+1), bsize)
+	return func(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+		byts := getData(contract.Code, new(big.Int).SetUint64(*pc+1), bsize)
 		stack.push(common.Bytes2Big(byts))
 		*pc += size
 		return nil, nil
@@ -719,7 +635,7 @@ func makePush(size uint64, bsize *big.Int) executionFunc {
 
 // make push instruction function
 func makeDup(size int64) executionFunc {
-	return func(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	return func(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 		stack.dup(int(size))
 		return nil, nil
 	}
@@ -729,7 +645,7 @@ func makeDup(size int64) executionFunc {
 func makeSwap(size int64) executionFunc {
 	// switch n + 1 otherwise n would be swapped with n
 	size += 1
-	return func(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
+	return func(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 		stack.swap(int(size))
 		return nil, nil
 	}
diff --git a/core/vm/int_pool_verifier.go b/core/vm/int_pool_verifier.go
deleted file mode 100644
index 61c83ba7e..000000000
--- a/core/vm/int_pool_verifier.go
+++ /dev/null
@@ -1,15 +0,0 @@
-// +build VERIFY_EVM_INTEGER_POOL
-
-package vm
-
-import "fmt"
-
-const verifyPool = true
-
-func verifyIntegerPool(ip *intPool) {
-	for i, item := range ip.pool.data {
-		if item.Cmp(checkVal) != 0 {
-			panic(fmt.Sprintf("%d'th item failed aggressive pool check. Value was modified", i))
-		}
-	}
-}
diff --git a/core/vm/int_pool_verifier_empty.go b/core/vm/int_pool_verifier_empty.go
deleted file mode 100644
index 982f8c6dd..000000000
--- a/core/vm/int_pool_verifier_empty.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build !VERIFY_EVM_INTEGER_POOL
-
-package vm
-
-const verifyPool = false
-
-func verifyIntegerPool(ip *intPool) {}
diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index 80e12c10b..073798274 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -17,7 +17,6 @@
 package vm
 
 import (
-	"errors"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/params"
@@ -25,13 +24,11 @@ import (
 
 type (
 	executionFunc       func(pc *uint64, env *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error)
-	gasFunc             func(params.GasTable, *EVM, *Contract, *Stack, *Memory, uint64) (uint64, error) // last parameter is the requested memory size as a uint64
+	gasFunc             func(params.GasTable, *EVM, *Contract, *Stack, *Memory, *big.Int) *big.Int
 	stackValidationFunc func(*Stack) error
 	memorySizeFunc      func(*Stack) *big.Int
 )
 
-var errGasUintOverflow = errors.New("gas uint64 overflow")
-
 type operation struct {
 	// op is the operation function
 	execute executionFunc
@@ -55,142 +52,149 @@ var defaultJumpTable = NewJumpTable()
 
 func NewJumpTable() [256]operation {
 	return [256]operation{
-		ADD: {
-			execute:       opAdd,
-			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+		STOP: {
+			execute:       opStop,
+			gasCost:       constGasFunc(new(big.Int)),
+			validateStack: makeStackFunc(0, 0),
+			halts:         true,
 			valid:         true,
 		},
-		SUB: {
-			execute:       opSub,
+		ADD: {
+			execute:       opAdd,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		MUL: {
 			execute:       opMul,
 			gasCost:       constGasFunc(GasFastStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
+			valid:         true,
+		},
+		SUB: {
+			execute:       opSub,
+			gasCost:       constGasFunc(GasFastestStep),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		DIV: {
 			execute:       opDiv,
 			gasCost:       constGasFunc(GasFastStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		SDIV: {
 			execute:       opSdiv,
 			gasCost:       constGasFunc(GasFastStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		MOD: {
 			execute:       opMod,
 			gasCost:       constGasFunc(GasFastStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		SMOD: {
 			execute:       opSmod,
 			gasCost:       constGasFunc(GasFastStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
+			valid:         true,
+		},
+		ADDMOD: {
+			execute:       opAddmod,
+			gasCost:       constGasFunc(GasMidStep),
+			validateStack: makeStackFunc(3, -2),
+			valid:         true,
+		},
+		MULMOD: {
+			execute:       opMulmod,
+			gasCost:       constGasFunc(GasMidStep),
+			validateStack: makeStackFunc(3, -2),
 			valid:         true,
 		},
 		EXP: {
 			execute:       opExp,
 			gasCost:       gasExp,
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		SIGNEXTEND: {
 			execute:       opSignExtend,
 			gasCost:       constGasFunc(GasFastStep),
-			validateStack: makeStackFunc(2, 1),
-			valid:         true,
-		},
-		NOT: {
-			execute:       opNot,
-			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(1, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		LT: {
 			execute:       opLt,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		GT: {
 			execute:       opGt,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		SLT: {
 			execute:       opSlt,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		SGT: {
 			execute:       opSgt,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		EQ: {
 			execute:       opEq,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		ISZERO: {
 			execute:       opIszero,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(1, 1),
+			validateStack: makeStackFunc(1, 0),
 			valid:         true,
 		},
 		AND: {
 			execute:       opAnd,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
+			valid:         true,
+		},
+		XOR: {
+			execute:       opXor,
+			gasCost:       constGasFunc(GasFastestStep),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		OR: {
 			execute:       opOr,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
-		XOR: {
-			execute:       opXor,
+		NOT: {
+			execute:       opNot,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(1, 0),
 			valid:         true,
 		},
 		BYTE: {
 			execute:       opByte,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(2, 1),
-			valid:         true,
-		},
-		ADDMOD: {
-			execute:       opAddmod,
-			gasCost:       constGasFunc(GasMidStep),
-			validateStack: makeStackFunc(3, 1),
-			valid:         true,
-		},
-		MULMOD: {
-			execute:       opMulmod,
-			gasCost:       constGasFunc(GasMidStep),
-			validateStack: makeStackFunc(3, 1),
+			validateStack: makeStackFunc(2, -1),
 			valid:         true,
 		},
 		SHA3: {
 			execute:       opSha3,
 			gasCost:       gasSha3,
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeStackFunc(2, -1),
 			memorySize:    memorySha3,
 			valid:         true,
 		},
@@ -203,7 +207,7 @@ func NewJumpTable() [256]operation {
 		BALANCE: {
 			execute:       opBalance,
 			gasCost:       gasBalance,
-			validateStack: makeStackFunc(0, 1),
+			validateStack: makeStackFunc(1, 0),
 			valid:         true,
 		},
 		ORIGIN: {
@@ -227,7 +231,7 @@ func NewJumpTable() [256]operation {
 		CALLDATALOAD: {
 			execute:       opCalldataLoad,
 			gasCost:       constGasFunc(GasFastestStep),
-			validateStack: makeStackFunc(1, 1),
+			validateStack: makeStackFunc(1, 0),
 			valid:         true,
 		},
 		CALLDATASIZE: {
@@ -239,7 +243,7 @@ func NewJumpTable() [256]operation {
 		CALLDATACOPY: {
 			execute:       opCalldataCopy,
 			gasCost:       gasCalldataCopy,
-			validateStack: makeStackFunc(3, 1),
+			validateStack: makeStackFunc(3, -3),
 			memorySize:    memoryCalldataCopy,
 			valid:         true,
 		},
@@ -249,36 +253,36 @@ func NewJumpTable() [256]operation {
 			validateStack: makeStackFunc(0, 1),
 			valid:         true,
 		},
-		EXTCODESIZE: {
-			execute:       opExtCodeSize,
-			gasCost:       gasExtCodeSize,
-			validateStack: makeStackFunc(1, 1),
-			valid:         true,
-		},
 		CODECOPY: {
 			execute:       opCodeCopy,
 			gasCost:       gasCodeCopy,
-			validateStack: makeStackFunc(3, 0),
+			validateStack: makeStackFunc(3, -3),
 			memorySize:    memoryCodeCopy,
 			valid:         true,
 		},
-		EXTCODECOPY: {
-			execute:       opExtCodeCopy,
-			gasCost:       gasExtCodeCopy,
-			validateStack: makeStackFunc(4, 0),
-			memorySize:    memoryExtCodeCopy,
-			valid:         true,
-		},
 		GASPRICE: {
 			execute:       opGasprice,
 			gasCost:       constGasFunc(GasQuickStep),
 			validateStack: makeStackFunc(0, 1),
 			valid:         true,
 		},
+		EXTCODESIZE: {
+			execute:       opExtCodeSize,
+			gasCost:       gasExtCodeSize,
+			validateStack: makeStackFunc(1, 0),
+			valid:         true,
+		},
+		EXTCODECOPY: {
+			execute:       opExtCodeCopy,
+			gasCost:       gasExtCodeCopy,
+			validateStack: makeStackFunc(4, -4),
+			memorySize:    memoryExtCodeCopy,
+			valid:         true,
+		},
 		BLOCKHASH: {
 			execute:       opBlockhash,
 			gasCost:       constGasFunc(GasExtStep),
-			validateStack: makeStackFunc(1, 1),
+			validateStack: makeStackFunc(1, 0),
 			valid:         true,
 		},
 		COINBASE: {
@@ -314,20 +318,20 @@ func NewJumpTable() [256]operation {
 		POP: {
 			execute:       opPop,
 			gasCost:       constGasFunc(GasQuickStep),
-			validateStack: makeStackFunc(1, 0),
+			validateStack: makeStackFunc(1, -1),
 			valid:         true,
 		},
 		MLOAD: {
 			execute:       opMload,
 			gasCost:       gasMLoad,
-			validateStack: makeStackFunc(1, 1),
+			validateStack: makeStackFunc(1, 0),
 			memorySize:    memoryMLoad,
 			valid:         true,
 		},
 		MSTORE: {
 			execute:       opMstore,
 			gasCost:       gasMStore,
-			validateStack: makeStackFunc(2, 0),
+			validateStack: makeStackFunc(2, -2),
 			memorySize:    memoryMStore,
 			valid:         true,
 		},
@@ -335,26 +339,34 @@ func NewJumpTable() [256]operation {
 			execute:       opMstore8,
 			gasCost:       gasMStore8,
 			memorySize:    memoryMStore8,
-			validateStack: makeStackFunc(2, 0),
+			validateStack: makeStackFunc(2, -2),
 
 			valid: true,
 		},
 		SLOAD: {
 			execute:       opSload,
 			gasCost:       gasSLoad,
-			validateStack: makeStackFunc(1, 1),
+			validateStack: makeStackFunc(1, 0),
 			valid:         true,
 		},
 		SSTORE: {
 			execute:       opSstore,
 			gasCost:       gasSStore,
-			validateStack: makeStackFunc(2, 0),
+			validateStack: makeStackFunc(2, -2),
 			valid:         true,
 		},
-		JUMPDEST: {
-			execute:       opJumpdest,
-			gasCost:       constGasFunc(params.JumpdestGas),
-			validateStack: makeStackFunc(0, 0),
+		JUMP: {
+			execute:       opJump,
+			gasCost:       constGasFunc(GasMidStep),
+			validateStack: makeStackFunc(1, -1),
+			jumps:         true,
+			valid:         true,
+		},
+		JUMPI: {
+			execute:       opJumpi,
+			gasCost:       constGasFunc(GasSlowStep),
+			validateStack: makeStackFunc(2, -2),
+			jumps:         true,
 			valid:         true,
 		},
 		PC: {
@@ -375,199 +387,10 @@ func NewJumpTable() [256]operation {
 			validateStack: makeStackFunc(0, 1),
 			valid:         true,
 		},
-		CREATE: {
-			execute:       opCreate,
-			gasCost:       gasCreate,
-			validateStack: makeStackFunc(3, 1),
-			memorySize:    memoryCreate,
-			valid:         true,
-		},
-		CALL: {
-			execute:       opCall,
-			gasCost:       gasCall,
-			validateStack: makeStackFunc(7, 1),
-			memorySize:    memoryCall,
-			valid:         true,
-		},
-		CALLCODE: {
-			execute:       opCallCode,
-			gasCost:       gasCallCode,
-			validateStack: makeStackFunc(7, 1),
-			memorySize:    memoryCall,
-			valid:         true,
-		},
-		DELEGATECALL: {
-			execute:       opDelegateCall,
-			gasCost:       gasDelegateCall,
-			validateStack: makeStackFunc(6, 1),
-			memorySize:    memoryDelegateCall,
-			valid:         true,
-		},
-		RETURN: {
-			execute:       opReturn,
-			gasCost:       gasReturn,
-			validateStack: makeStackFunc(2, 0),
-			memorySize:    memoryReturn,
-			halts:         true,
-			valid:         true,
-		},
-		SUICIDE: {
-			execute:       opSuicide,
-			gasCost:       gasSuicide,
-			validateStack: makeStackFunc(1, 0),
-			halts:         true,
-			valid:         true,
-		},
-		JUMP: {
-			execute:       opJump,
-			gasCost:       constGasFunc(GasMidStep),
-			validateStack: makeStackFunc(1, 0),
-			jumps:         true,
-			valid:         true,
-		},
-		JUMPI: {
-			execute:       opJumpi,
-			gasCost:       constGasFunc(GasSlowStep),
-			validateStack: makeStackFunc(2, 0),
-			jumps:         true,
-			valid:         true,
-		},
-		STOP: {
-			execute:       opStop,
-			gasCost:       constGasFunc(0),
+		JUMPDEST: {
+			execute:       opJumpdest,
+			gasCost:       constGasFunc(params.JumpdestGas),
 			validateStack: makeStackFunc(0, 0),
-			halts:         true,
-			valid:         true,
-		},
-		LOG0: {
-			execute:       makeLog(0),
-			gasCost:       makeGasLog(0),
-			validateStack: makeStackFunc(2, 0),
-			memorySize:    memoryLog,
-			valid:         true,
-		},
-		LOG1: {
-			execute:       makeLog(1),
-			gasCost:       makeGasLog(1),
-			validateStack: makeStackFunc(3, 0),
-			memorySize:    memoryLog,
-			valid:         true,
-		},
-		LOG2: {
-			execute:       makeLog(2),
-			gasCost:       makeGasLog(2),
-			validateStack: makeStackFunc(4, 0),
-			memorySize:    memoryLog,
-			valid:         true,
-		},
-		LOG3: {
-			execute:       makeLog(3),
-			gasCost:       makeGasLog(3),
-			validateStack: makeStackFunc(5, 0),
-			memorySize:    memoryLog,
-			valid:         true,
-		},
-		LOG4: {
-			execute:       makeLog(4),
-			gasCost:       makeGasLog(4),
-			validateStack: makeStackFunc(6, 0),
-			memorySize:    memoryLog,
-			valid:         true,
-		},
-		SWAP1: {
-			execute:       makeSwap(1),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(2, 0),
-			valid:         true,
-		},
-		SWAP2: {
-			execute:       makeSwap(2),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(3, 0),
-			valid:         true,
-		},
-		SWAP3: {
-			execute:       makeSwap(3),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(4, 0),
-			valid:         true,
-		},
-		SWAP4: {
-			execute:       makeSwap(4),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(5, 0),
-			valid:         true,
-		},
-		SWAP5: {
-			execute:       makeSwap(5),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(6, 0),
-			valid:         true,
-		},
-		SWAP6: {
-			execute:       makeSwap(6),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(7, 0),
-			valid:         true,
-		},
-		SWAP7: {
-			execute:       makeSwap(7),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(8, 0),
-			valid:         true,
-		},
-		SWAP8: {
-			execute:       makeSwap(8),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(9, 0),
-			valid:         true,
-		},
-		SWAP9: {
-			execute:       makeSwap(9),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(10, 0),
-			valid:         true,
-		},
-		SWAP10: {
-			execute:       makeSwap(10),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(11, 0),
-			valid:         true,
-		},
-		SWAP11: {
-			execute:       makeSwap(11),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(12, 0),
-			valid:         true,
-		},
-		SWAP12: {
-			execute:       makeSwap(12),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(13, 0),
-			valid:         true,
-		},
-		SWAP13: {
-			execute:       makeSwap(13),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(14, 0),
-			valid:         true,
-		},
-		SWAP14: {
-			execute:       makeSwap(14),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(15, 0),
-			valid:         true,
-		},
-		SWAP15: {
-			execute:       makeSwap(15),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(16, 0),
-			valid:         true,
-		},
-		SWAP16: {
-			execute:       makeSwap(16),
-			gasCost:       gasSwap,
-			validateStack: makeStackFunc(17, 0),
 			valid:         true,
 		},
 		PUSH1: {
@@ -765,97 +588,271 @@ func NewJumpTable() [256]operation {
 		DUP1: {
 			execute:       makeDup(1),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(1, 1),
+			validateStack: makeDupStackFunc(1),
 			valid:         true,
 		},
 		DUP2: {
 			execute:       makeDup(2),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(2, 1),
+			validateStack: makeDupStackFunc(2),
 			valid:         true,
 		},
 		DUP3: {
 			execute:       makeDup(3),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(3, 1),
+			validateStack: makeDupStackFunc(3),
 			valid:         true,
 		},
 		DUP4: {
 			execute:       makeDup(4),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(4, 1),
+			validateStack: makeDupStackFunc(4),
 			valid:         true,
 		},
 		DUP5: {
 			execute:       makeDup(5),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(5, 1),
+			validateStack: makeDupStackFunc(5),
 			valid:         true,
 		},
 		DUP6: {
 			execute:       makeDup(6),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(6, 1),
+			validateStack: makeDupStackFunc(6),
 			valid:         true,
 		},
 		DUP7: {
 			execute:       makeDup(7),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(7, 1),
+			validateStack: makeDupStackFunc(7),
 			valid:         true,
 		},
 		DUP8: {
 			execute:       makeDup(8),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(8, 1),
+			validateStack: makeDupStackFunc(8),
 			valid:         true,
 		},
 		DUP9: {
 			execute:       makeDup(9),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(9, 1),
+			validateStack: makeDupStackFunc(9),
 			valid:         true,
 		},
 		DUP10: {
 			execute:       makeDup(10),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(10, 1),
+			validateStack: makeDupStackFunc(10),
 			valid:         true,
 		},
 		DUP11: {
 			execute:       makeDup(11),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(11, 1),
+			validateStack: makeDupStackFunc(11),
 			valid:         true,
 		},
 		DUP12: {
 			execute:       makeDup(12),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(12, 1),
+			validateStack: makeDupStackFunc(12),
 			valid:         true,
 		},
 		DUP13: {
 			execute:       makeDup(13),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(13, 1),
+			validateStack: makeDupStackFunc(13),
 			valid:         true,
 		},
 		DUP14: {
 			execute:       makeDup(14),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(14, 1),
+			validateStack: makeDupStackFunc(14),
 			valid:         true,
 		},
 		DUP15: {
 			execute:       makeDup(15),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(15, 1),
+			validateStack: makeDupStackFunc(15),
 			valid:         true,
 		},
 		DUP16: {
 			execute:       makeDup(16),
 			gasCost:       gasDup,
-			validateStack: makeStackFunc(16, 1),
+			validateStack: makeDupStackFunc(16),
+			valid:         true,
+		},
+		SWAP1: {
+			execute:       makeSwap(1),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(2),
+			valid:         true,
+		},
+		SWAP2: {
+			execute:       makeSwap(2),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(3),
+			valid:         true,
+		},
+		SWAP3: {
+			execute:       makeSwap(3),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(4),
+			valid:         true,
+		},
+		SWAP4: {
+			execute:       makeSwap(4),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(5),
+			valid:         true,
+		},
+		SWAP5: {
+			execute:       makeSwap(5),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(6),
+			valid:         true,
+		},
+		SWAP6: {
+			execute:       makeSwap(6),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(7),
+			valid:         true,
+		},
+		SWAP7: {
+			execute:       makeSwap(7),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(8),
+			valid:         true,
+		},
+		SWAP8: {
+			execute:       makeSwap(8),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(9),
+			valid:         true,
+		},
+		SWAP9: {
+			execute:       makeSwap(9),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(10),
+			valid:         true,
+		},
+		SWAP10: {
+			execute:       makeSwap(10),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(11),
+			valid:         true,
+		},
+		SWAP11: {
+			execute:       makeSwap(11),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(12),
+			valid:         true,
+		},
+		SWAP12: {
+			execute:       makeSwap(12),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(13),
+			valid:         true,
+		},
+		SWAP13: {
+			execute:       makeSwap(13),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(14),
+			valid:         true,
+		},
+		SWAP14: {
+			execute:       makeSwap(14),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(15),
+			valid:         true,
+		},
+		SWAP15: {
+			execute:       makeSwap(15),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(16),
+			valid:         true,
+		},
+		SWAP16: {
+			execute:       makeSwap(16),
+			gasCost:       gasSwap,
+			validateStack: makeSwapStackFunc(17),
+			valid:         true,
+		},
+		LOG0: {
+			execute:       makeLog(0),
+			gasCost:       makeGasLog(0),
+			validateStack: makeStackFunc(2, -2),
+			memorySize:    memoryLog,
+			valid:         true,
+		},
+		LOG1: {
+			execute:       makeLog(1),
+			gasCost:       makeGasLog(1),
+			validateStack: makeStackFunc(3, -3),
+			memorySize:    memoryLog,
+			valid:         true,
+		},
+		LOG2: {
+			execute:       makeLog(2),
+			gasCost:       makeGasLog(2),
+			validateStack: makeStackFunc(4, -4),
+			memorySize:    memoryLog,
+			valid:         true,
+		},
+		LOG3: {
+			execute:       makeLog(3),
+			gasCost:       makeGasLog(3),
+			validateStack: makeStackFunc(5, -5),
+			memorySize:    memoryLog,
+			valid:         true,
+		},
+		LOG4: {
+			execute:       makeLog(4),
+			gasCost:       makeGasLog(4),
+			validateStack: makeStackFunc(6, -6),
+			memorySize:    memoryLog,
+			valid:         true,
+		},
+		CREATE: {
+			execute:       opCreate,
+			gasCost:       gasCreate,
+			validateStack: makeStackFunc(3, -2),
+			memorySize:    memoryCreate,
+			valid:         true,
+		},
+		CALL: {
+			execute:       opCall,
+			gasCost:       gasCall,
+			validateStack: makeStackFunc(7, -6),
+			memorySize:    memoryCall,
+			valid:         true,
+		},
+		CALLCODE: {
+			execute:       opCallCode,
+			gasCost:       gasCallCode,
+			validateStack: makeStackFunc(7, -6),
+			memorySize:    memoryCall,
+			valid:         true,
+		},
+		RETURN: {
+			execute:       opReturn,
+			gasCost:       gasReturn,
+			validateStack: makeStackFunc(2, -2),
+			memorySize:    memoryReturn,
+			halts:         true,
+			valid:         true,
+		},
+		DELEGATECALL: {
+			execute:       opDelegateCall,
+			gasCost:       gasDelegateCall,
+			validateStack: makeStackFunc(6, -5),
+			memorySize:    memoryDelegateCall,
+			valid:         true,
+		},
+		SELFDESTRUCT: {
+			execute:       opSuicide,
+			gasCost:       gasSuicide,
+			validateStack: makeStackFunc(1, -1),
+			halts:         true,
 			valid:         true,
 		},
 	}
diff --git a/core/vm/logger_test.go b/core/vm/logger_test.go
index ca60cba43..1d0bd96fa 100644
--- a/core/vm/logger_test.go
+++ b/core/vm/logger_test.go
@@ -56,7 +56,7 @@ func TestStoreCapture(t *testing.T) {
 		logger   = NewStructLogger(nil)
 		mem      = NewMemory()
 		stack    = newstack()
-		contract = NewContract(&dummyContractRef{}, &dummyContractRef{}, new(big.Int), 0)
+		contract = NewContract(&dummyContractRef{}, &dummyContractRef{}, new(big.Int), new(big.Int))
 	)
 	stack.push(big.NewInt(1))
 	stack.push(big.NewInt(0))
@@ -78,7 +78,7 @@ func TestStorageCapture(t *testing.T) {
 	t.Skip("implementing this function is difficult. it requires all sort of interfaces to be implemented which isn't trivial. The value (the actual test) isn't worth it")
 	var (
 		ref      = &dummyContractRef{}
-		contract = NewContract(ref, ref, new(big.Int), 0)
+		contract = NewContract(ref, ref, new(big.Int), new(big.Int))
 		env      = NewEVM(Context{}, dummyStateDB{ref: ref}, params.TestChainConfig, Config{EnableJit: false, ForceJit: false})
 		logger   = NewStructLogger(nil)
 		mem      = NewMemory()
diff --git a/core/vm/memory.go b/core/vm/memory.go
index 99a84d227..d01188417 100644
--- a/core/vm/memory.go
+++ b/core/vm/memory.go
@@ -20,12 +20,11 @@ import "fmt"
 
 // Memory implements a simple memory model for the ethereum virtual machine.
 type Memory struct {
-	store       []byte
-	lastGasCost uint64
+	store []byte
 }
 
 func NewMemory() *Memory {
-	return &Memory{}
+	return &Memory{nil}
 }
 
 // Set sets offset + size to value
diff --git a/core/vm/opcodes.go b/core/vm/opcodes.go
index 9d2b037a5..d4ba7f156 100644
--- a/core/vm/opcodes.go
+++ b/core/vm/opcodes.go
@@ -202,7 +202,7 @@ const (
 	RETURN
 	DELEGATECALL
 
-	SUICIDE = 0xff
+	SELFDESTRUCT = 0xff
 )
 
 // Since the opcodes aren't all in order we can't use a regular slice
@@ -355,7 +355,7 @@ var opCodeToString = map[OpCode]string{
 	RETURN:       "RETURN",
 	CALLCODE:     "CALLCODE",
 	DELEGATECALL: "DELEGATECALL",
-	SUICIDE:      "SUICIDE",
+	SELFDESTRUCT: "SELFDESTRUCT",
 
 	PUSH: "PUSH",
 	DUP:  "DUP",
@@ -501,7 +501,7 @@ var stringToOp = map[string]OpCode{
 	"CALL":         CALL,
 	"RETURN":       RETURN,
 	"CALLCODE":     CALLCODE,
-	"SUICIDE":      SUICIDE,
+	"SELFDESTRUCT": SELFDESTRUCT,
 }
 
 func StringToOp(str string) OpCode {
diff --git a/core/vm/runtime/env.go b/core/vm/runtime/env.go
index 9aa88e669..a25c6d71c 100644
--- a/core/vm/runtime/env.go
+++ b/core/vm/runtime/env.go
@@ -36,7 +36,7 @@ func NewEnv(cfg *Config, state *state.StateDB) *vm.EVM {
 		BlockNumber: cfg.BlockNumber,
 		Time:        cfg.Time,
 		Difficulty:  cfg.Difficulty,
-		GasLimit:    new(big.Int).SetUint64(cfg.GasLimit),
+		GasLimit:    cfg.GasLimit,
 		GasPrice:    new(big.Int),
 	}
 
diff --git a/core/vm/runtime/runtime.go b/core/vm/runtime/runtime.go
index cf46603db..b5adb982c 100644
--- a/core/vm/runtime/runtime.go
+++ b/core/vm/runtime/runtime.go
@@ -17,7 +17,6 @@
 package runtime
 
 import (
-	"math"
 	"math/big"
 	"time"
 
@@ -38,7 +37,7 @@ type Config struct {
 	Coinbase    common.Address
 	BlockNumber *big.Int
 	Time        *big.Int
-	GasLimit    uint64
+	GasLimit    *big.Int
 	GasPrice    *big.Int
 	Value       *big.Int
 	DisableJit  bool // "disable" so it's enabled by default
@@ -69,8 +68,8 @@ func setDefaults(cfg *Config) {
 	if cfg.Time == nil {
 		cfg.Time = big.NewInt(time.Now().Unix())
 	}
-	if cfg.GasLimit == 0 {
-		cfg.GasLimit = math.MaxUint64
+	if cfg.GasLimit == nil {
+		cfg.GasLimit = new(big.Int).Set(common.MaxBig)
 	}
 	if cfg.GasPrice == nil {
 		cfg.GasPrice = new(big.Int)
@@ -113,7 +112,7 @@ func Execute(code, input []byte, cfg *Config) ([]byte, *state.StateDB, error) {
 	receiver.SetCode(crypto.Keccak256Hash(code), code)
 
 	// Call the code with the given configuration.
-	ret, _, err := vmenv.Call(
+	ret, err := vmenv.Call(
 		sender,
 		receiver.Address(),
 		input,
@@ -141,13 +140,12 @@ func Create(input []byte, cfg *Config) ([]byte, common.Address, error) {
 	)
 
 	// Call the code with the given configuration.
-	code, address, _, err := vmenv.Create(
+	return vmenv.Create(
 		sender,
 		input,
 		cfg.GasLimit,
 		cfg.Value,
 	)
-	return code, address, err
 }
 
 // Call executes the code given by the contract's address. It will return the
@@ -162,7 +160,7 @@ func Call(address common.Address, input []byte, cfg *Config) ([]byte, error) {
 
 	sender := cfg.State.GetOrNewStateObject(cfg.Origin)
 	// Call the code with the given configuration.
-	ret, _, err := vmenv.Call(
+	ret, err := vmenv.Call(
 		sender,
 		address,
 		input,
diff --git a/core/vm/runtime/runtime_test.go b/core/vm/runtime/runtime_test.go
index 8ad74a89a..1e618b688 100644
--- a/core/vm/runtime/runtime_test.go
+++ b/core/vm/runtime/runtime_test.go
@@ -39,8 +39,8 @@ func TestDefaults(t *testing.T) {
 	if cfg.Time == nil {
 		t.Error("expected time to be non nil")
 	}
-	if cfg.GasLimit == 0 {
-		t.Error("didn't expect gaslimit to be zero")
+	if cfg.GasLimit == nil {
+		t.Error("expected time to be non nil")
 	}
 	if cfg.GasPrice == nil {
 		t.Error("expected time to be non nil")
diff --git a/core/vm/stack_table.go b/core/vm/stack_table.go
index 0936ef06f..eed8805f2 100644
--- a/core/vm/stack_table.go
+++ b/core/vm/stack_table.go
@@ -6,15 +6,23 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 )
 
-func makeStackFunc(pop, push int) stackValidationFunc {
+func makeStackFunc(pop, diff int) stackValidationFunc {
 	return func(stack *Stack) error {
 		if err := stack.require(pop); err != nil {
 			return err
 		}
 
-		if push > 0 && stack.len()-pop+push > int(params.StackLimit) {
+		if int64(stack.len()+diff) > params.StackLimit.Int64() {
 			return fmt.Errorf("stack limit reached %d (%d)", stack.len(), params.StackLimit)
 		}
 		return nil
 	}
 }
+
+func makeDupStackFunc(n int) stackValidationFunc {
+	return makeStackFunc(n, 1)
+}
+
+func makeSwapStackFunc(n int) stackValidationFunc {
+	return makeStackFunc(n, 0)
+}
diff --git a/core/vm/intpool.go b/core/vm/virtual_machine.go
index 4f1228e14..629108884 100644
--- a/core/vm/intpool.go
+++ b/core/vm/virtual_machine.go
@@ -1,4 +1,4 @@
-// Copyright 2017 The go-ethereum Authors
+// Copyright 2014 The go-ethereum Authors
 // This file is part of the go-ethereum library.
 //
 // The go-ethereum library is free software: you can redistribute it and/or modify
@@ -16,34 +16,7 @@
 
 package vm
 
-import "math/big"
-
-var checkVal = big.NewInt(-42)
-
-// intPool is a pool of big integers that
-// can be reused for all big.Int operations.
-type intPool struct {
-	pool *Stack
-}
-
-func newIntPool() *intPool {
-	return &intPool{pool: newstack()}
-}
-
-func (p *intPool) get() *big.Int {
-	if p.pool.len() > 0 {
-		return p.pool.pop()
-	}
-	return new(big.Int)
-}
-func (p *intPool) put(is ...*big.Int) {
-	for _, i := range is {
-		// verifyPool is a build flag. Pool verification makes sure the integrity
-		// of the integer pool by comparing values to a default value.
-		if verifyPool {
-			i.Set(checkVal)
-		}
-
-		p.pool.push(i)
-	}
+// VirtualMachine is an EVM interface
+type VirtualMachine interface {
+	Run(*Contract, []byte) ([]byte, error)
 }
diff --git a/core/vm/interpreter.go b/core/vm/vm.go
index ad41e3602..05886a863 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/vm.go
@@ -23,7 +23,6 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
@@ -61,7 +60,6 @@ type Interpreter struct {
 	env      *EVM
 	cfg      Config
 	gasTable params.GasTable
-	intPool  *intPool
 }
 
 // NewInterpreter returns a new instance of the Interpreter.
@@ -77,7 +75,6 @@ func NewInterpreter(env *EVM, cfg Config) *Interpreter {
 		env:      env,
 		cfg:      cfg,
 		gasTable: env.ChainConfig().GasTable(env.BlockNumber),
-		intPool:  newIntPool(),
 	}
 }
 
@@ -109,18 +106,14 @@ func (evm *Interpreter) Run(contract *Contract, input []byte) (ret []byte, err e
 		// For optimisation reason we're using uint64 as the program counter.
 		// It's theoretically possible to go above 2^64. The YP defines the PC to be uint256. Practically much less so feasible.
 		pc   = uint64(0) // program counter
-		cost uint64
+		cost *big.Int
 	)
 	contract.Input = input
 
 	// User defer pattern to check for an error and, based on the error being nil or not, use all gas and return.
 	defer func() {
 		if err != nil && evm.cfg.Debug {
-			// XXX For debugging
-			//fmt.Printf("%04d: %8v    cost = %-8d stack = %-8d ERR = %v\n", pc, op, cost, stack.len(), err)
-			// TODO update the tracer
-			g, c := new(big.Int).SetUint64(contract.Gas), new(big.Int).SetUint64(cost)
-			evm.cfg.Tracer.CaptureState(evm.env, pc, op, g, c, mem, stack, contract, evm.env.depth, err)
+			evm.cfg.Tracer.CaptureState(evm.env, pc, op, contract.Gas, cost, mem, stack, contract, evm.env.depth, err)
 		}
 	}()
 
@@ -133,7 +126,7 @@ func (evm *Interpreter) Run(contract *Contract, input []byte) (ret []byte, err e
 	}
 
 	// The Interpreter main run loop (contextual). This loop runs until either an
-	// explicit STOP, RETURN or SUICIDE is executed, an error occurred during
+	// explicit STOP, RETURN or SELFDESTRUCT is executed, an error occurred during
 	// the execution of one of the operations or until the evm.done is set by
 	// the parent context.Context.
 	for atomic.LoadInt32(&evm.env.abort) == 0 {
@@ -154,47 +147,34 @@ func (evm *Interpreter) Run(contract *Contract, input []byte) (ret []byte, err e
 			return nil, err
 		}
 
-		var memorySize uint64
+		var memorySize *big.Int
 		// calculate the new memory size and expand the memory to fit
 		// the operation
 		if operation.memorySize != nil {
-			memSize, overflow := bigUint64(operation.memorySize(stack))
-			if overflow {
-				return nil, errGasUintOverflow
-			}
+			memorySize = operation.memorySize(stack)
 			// memory is expanded in words of 32 bytes. Gas
 			// is also calculated in words.
-			if memorySize, overflow = math.SafeMul(toWordSize(memSize), 32); overflow {
-				return nil, errGasUintOverflow
-			}
+			memorySize.Mul(toWordSize(memorySize), big.NewInt(32))
 		}
 
 		if !evm.cfg.DisableGasMetering {
 			// consume the gas and return an error if not enough gas is available.
 			// cost is explicitly set so that the capture state defer method cas get the proper cost
-			cost, err = operation.gasCost(evm.gasTable, evm.env, contract, stack, mem, memorySize)
-			if err != nil || !contract.UseGas(cost) {
+			cost = operation.gasCost(evm.gasTable, evm.env, contract, stack, mem, memorySize)
+			if !contract.UseGas(cost) {
 				return nil, ErrOutOfGas
 			}
 		}
-		if memorySize > 0 {
-			mem.Resize(memorySize)
+		if memorySize != nil {
+			mem.Resize(memorySize.Uint64())
 		}
 
 		if evm.cfg.Debug {
-			g, c := new(big.Int).SetUint64(contract.Gas), new(big.Int).SetUint64(cost)
-			evm.cfg.Tracer.CaptureState(evm.env, pc, op, g, c, mem, stack, contract, evm.env.depth, err)
+			evm.cfg.Tracer.CaptureState(evm.env, pc, op, contract.Gas, cost, mem, stack, contract, evm.env.depth, err)
 		}
-		// XXX For debugging
-		//fmt.Printf("%04d: %8v    cost = %-8d stack = %-8d\n", pc, op, cost, stack.len())
 
 		// execute the operation
 		res, err := operation.execute(&pc, evm.env, contract, mem, stack)
-		// verifyPool is a build flag. Pool verification makes sure the integrity
-		// of the integer pool by comparing values to a default value.
-		if verifyPool {
-			verifyIntegerPool(evm.intPool)
-		}
 		switch {
 		case err != nil:
 			return nil, err