1 files changed, 7 insertions, 24 deletions
diff --git a/core/vm/common.go b/core/vm/common.go
index ead30fc..90ba4a4 100644
--- a/core/vm/common.go
+++ b/core/vm/common.go
@@ -17,15 +17,14 @@
 package vm
 
 import (
-	"math/big"
-
-	"github.com/ava-labs/go-ethereum/common"
-	"github.com/ava-labs/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/holiman/uint256"
 )
 
 // calcMemSize64 calculates the required memory size, and returns
 // the size and whether the result overflowed uint64
-func calcMemSize64(off, l *big.Int) (uint64, bool) {
+func calcMemSize64(off, l *uint256.Int) (uint64, bool) {
 	if !l.IsUint64() {
 		return 0, true
 	}
@@ -35,16 +34,16 @@ func calcMemSize64(off, l *big.Int) (uint64, bool) {
 // calcMemSize64WithUint calculates the required memory size, and returns
 // the size and whether the result overflowed uint64
 // Identical to calcMemSize64, but length is a uint64
-func calcMemSize64WithUint(off *big.Int, length64 uint64) (uint64, bool) {
+func calcMemSize64WithUint(off *uint256.Int, length64 uint64) (uint64, bool) {
 	// if length is zero, memsize is always zero, regardless of offset
 	if length64 == 0 {
 		return 0, false
 	}
 	// Check that offset doesn't overflow
-	if !off.IsUint64() {
+	offset64, overflow := off.Uint64WithOverflow()
+	if overflow {
 		return 0, true
 	}
-	offset64 := off.Uint64()
 	val := offset64 + length64
 	// if value < either of it's parts, then it overflowed
 	return val, val < offset64
@@ -64,22 +63,6 @@ func getData(data []byte, start uint64, size uint64) []byte {
 	return common.RightPadBytes(data[start:end], int(size))
 }
 
-// getDataBig 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 getDataBig(data []byte, start *big.Int, size *big.Int) []byte {
-	dlen := big.NewInt(int64(len(data)))
-
-	s := math.BigMin(start, dlen)
-	e := math.BigMin(new(big.Int).Add(s, size), dlen)
-	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.IsUint64()
-}
-
 // toWordSize returns the ceiled word size required for memory expansion.
 func toWordSize(size uint64) uint64 {
 	if size > math.MaxUint64-31 {