1 files changed, 11 insertions, 67 deletions

diff --git a/core/vm/common.go b/core/vm/common.go
index 2878b92d2..b7b9a6a9c 100644
--- a/core/vm/common.go
+++ b/core/vm/common.go
@@ -21,28 +21,11 @@ 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
@@ -54,48 +37,6 @@ 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 {
@@ -106,14 +47,17 @@ func getData(data []byte, start, size *big.Int) []byte {
 	return common.RightPadBytes(data[s.Uint64():e.Uint64()], int(size.Uint64()))
 }
 
-// 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
+// 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
 	}
 
-	// Sub the amount of gas from the remaining
-	gas.Sub(gas, amount)
-	return true
+	return (size + 31) / 32
 }