core/vm: use uint256 in EVM implementation (#20787)

* core/vm: use fixed uint256 library instead of big

* core/vm: remove intpools

* core/vm: upgrade uint256, fixes uint256.NewFromBig

* core/vm: use uint256.Int by value in Stack

* core/vm: upgrade uint256 to v1.0.0

* core/vm: don't preallocate space for 1024 stack items (only 16)

Co-authored-by: Martin Holst Swende <martin@swende.se>

core/vm/common.go

@@ -17,15 +17,14 @@
 package vm
 
 import (
-	"math/big"
-
 	"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 {

core/vm/contract.go

@@ -20,6 +20,7 @@ import (
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/holiman/uint256"
 )
 
 // ContractRef is a reference to the contract's backing object
@@ -81,11 +82,11 @@ func NewContract(caller ContractRef, object ContractRef, value *big.Int, gas uin
 	return c
 }
 
-func (c *Contract) validJumpdest(dest *big.Int) bool {
+func (c *Contract) validJumpdest(dest *uint256.Int) bool {
-	udest := dest.Uint64()
+	udest, overflow := dest.Uint64WithOverflow()
-	// PC cannot go beyond len(code) and certainly can't be bigger than 63 bits.
+	// PC cannot go beyond len(code) and certainly can't be bigger than 63bits.
 	// Don't bother checking for JUMPDEST in that case.
-	if dest.BitLen() >= 63 || udest >= uint64(len(c.Code)) {
+	if overflow || udest >= uint64(len(c.Code)) {
 		return false
 	}
 	// Only JUMPDESTs allowed for destinations

core/vm/eips.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/holiman/uint256"
 )
 
 // EnableEIP enables the given EIP on the config.
@@ -63,7 +64,7 @@ func enable1884(jt *JumpTable) {
 }
 
 func opSelfBalance(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx) ([]byte, error) {
-	balance := interpreter.intPool.get().Set(interpreter.evm.StateDB.GetBalance(callContext.contract.Address()))
+	balance, _ := uint256.FromBig(interpreter.evm.StateDB.GetBalance(callContext.contract.Address()))
 	callContext.stack.push(balance)
 	return nil, nil
 }
@@ -83,7 +84,7 @@ func enable1344(jt *JumpTable) {
 
 // opChainID implements CHAINID opcode
 func opChainID(pc *uint64, interpreter *EVMInterpreter, callContext *callCtx) ([]byte, error) {
-	chainId := interpreter.intPool.get().Set(interpreter.evm.chainConfig.ChainID)
+	chainId, _ := uint256.FromBig(interpreter.evm.chainConfig.ChainID)
 	callContext.stack.push(chainId)
 	return nil, nil
 }

core/vm/evm.go

@@ -352,7 +352,7 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 	// This doesn't matter on Mainnet, where all empties are gone at the time of Byzantium,
 	// but is the correct thing to do and matters on other networks, in tests, and potential
 	// future scenarios
-	evm.StateDB.AddBalance(addr, bigZero)
+	evm.StateDB.AddBalance(addr, big.NewInt(0))
 
 	// When an error was returned by the EVM or when setting the creation code
 	// above we revert to the snapshot and consume any gas remaining. Additionally

core/vm/gas.go

@@ -17,7 +17,7 @@
 package vm
 
 import (
-	"math/big"
+	"github.com/holiman/uint256"
 )
 
 // Gas costs
@@ -34,7 +34,7 @@ const (
 //
 // The cost of gas was changed during the homestead price change HF.
 // As part of EIP 150 (TangerineWhistle), the returned gas is gas - base * 63 / 64.
-func callGas(isEip150 bool, availableGas, base uint64, callCost *big.Int) (uint64, error) {
+func callGas(isEip150 bool, availableGas, base uint64, callCost *uint256.Int) (uint64, error) {
 	if isEip150 {
 		availableGas = availableGas - base
 		gas := availableGas - availableGas/64

core/vm/gas_table.go

@@ -70,7 +70,7 @@ func memoryCopierGas(stackpos int) gasFunc {
 			return 0, err
 		}
 		// And gas for copying data, charged per word at param.CopyGas
-		words, overflow := bigUint64(stack.Back(stackpos))
+		words, overflow := stack.Back(stackpos).Uint64WithOverflow()
 		if overflow {
 			return 0, ErrGasUintOverflow
 		}
@@ -96,7 +96,7 @@ var (
 func gasSStore(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
 	var (
 		y, x    = stack.Back(1), stack.Back(0)
-		current = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
+		current = evm.StateDB.GetState(contract.Address(), common.Hash(x.Bytes32()))
 	)
 	// The legacy gas metering only takes into consideration the current state
 	// Legacy rules should be applied if we are in Petersburg (removal of EIP-1283)
@@ -131,11 +131,11 @@ func gasSStore(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySi
 	// 	  2.2.2. If original value equals new value (this storage slot is reset)
 	//       2.2.2.1. If original value is 0, add 19800 gas to refund counter.
 	// 	     2.2.2.2. Otherwise, add 4800 gas to refund counter.
-	value := common.BigToHash(y)
+	value := common.Hash(y.Bytes32())
 	if current == value { // noop (1)
 		return params.NetSstoreNoopGas, nil
 	}
-	original := evm.StateDB.GetCommittedState(contract.Address(), common.BigToHash(x))
+	original := evm.StateDB.GetCommittedState(contract.Address(), common.Hash(x.Bytes32()))
 	if original == current {
 		if original == (common.Hash{}) { // create slot (2.1.1)
 			return params.NetSstoreInitGas, nil
@@ -183,14 +183,14 @@ func gasSStoreEIP2200(evm *EVM, contract *Contract, stack *Stack, mem *Memory, m
 	// Gas sentry honoured, do the actual gas calculation based on the stored value
 	var (
 		y, x    = stack.Back(1), stack.Back(0)
-		current = evm.StateDB.GetState(contract.Address(), common.BigToHash(x))
+		current = evm.StateDB.GetState(contract.Address(), common.Hash(x.Bytes32()))
 	)
-	value := common.BigToHash(y)
+	value := common.Hash(y.Bytes32())
 
 	if current == value { // noop (1)
 		return params.SstoreNoopGasEIP2200, nil
 	}
-	original := evm.StateDB.GetCommittedState(contract.Address(), common.BigToHash(x))
+	original := evm.StateDB.GetCommittedState(contract.Address(), common.Hash(x.Bytes32()))
 	if original == current {
 		if original == (common.Hash{}) { // create slot (2.1.1)
 			return params.SstoreInitGasEIP2200, nil
@@ -219,7 +219,7 @@ func gasSStoreEIP2200(evm *EVM, contract *Contract, stack *Stack, mem *Memory, m
 
 func makeGasLog(n uint64) gasFunc {
 	return func(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
-		requestedSize, overflow := bigUint64(stack.Back(1))
+		requestedSize, overflow := stack.Back(1).Uint64WithOverflow()
 		if overflow {
 			return 0, ErrGasUintOverflow
 		}
@@ -252,7 +252,7 @@ func gasSha3(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize
 	if err != nil {
 		return 0, err
 	}
-	wordGas, overflow := bigUint64(stack.Back(1))
+	wordGas, overflow := stack.Back(1).Uint64WithOverflow()
 	if overflow {
 		return 0, ErrGasUintOverflow
 	}
@@ -286,7 +286,7 @@ func gasCreate2(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memoryS
 	if err != nil {
 		return 0, err
 	}
-	wordGas, overflow := bigUint64(stack.Back(2))
+	wordGas, overflow := stack.Back(2).Uint64WithOverflow()
 	if overflow {
 		return 0, ErrGasUintOverflow
 	}
@@ -328,8 +328,8 @@ func gasExpEIP158(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memor
 func gasCall(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
 	var (
 		gas            uint64
-		transfersValue = stack.Back(2).Sign() != 0
+		transfersValue = !stack.Back(2).IsZero()
-		address        = common.BigToAddress(stack.Back(1))
+		address        = common.Address(stack.Back(1).Bytes20())
 	)
 	if evm.chainRules.IsEIP158 {
 		if transfersValue && evm.StateDB.Empty(address) {
@@ -422,7 +422,7 @@ func gasSelfdestruct(evm *EVM, contract *Contract, stack *Stack, mem *Memory, me
 	// EIP150 homestead gas reprice fork:
 	if evm.chainRules.IsEIP150 {
 		gas = params.SelfdestructGasEIP150
-		var address = common.BigToAddress(stack.Back(0))
+		var address = common.Address(stack.Back(0).Bytes20())
 
 		if evm.chainRules.IsEIP158 {
 			// if empty and transfers value

core/vm/instructions_test.go

@@ -21,12 +21,12 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
-	"math/big"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/holiman/uint256"
 )
 
 type TwoOperandTestcase struct {
@@ -98,42 +98,23 @@ func testTwoOperandOp(t *testing.T, tests []TwoOperandTestcase, opFn executionFu
 		pc             = uint64(0)
 		evmInterpreter = env.interpreter.(*EVMInterpreter)
 	)
-	// Stuff a couple of nonzero bigints into pool, to ensure that ops do not rely on pooled integers to be zero
-	evmInterpreter.intPool = poolOfIntPools.get()
-	evmInterpreter.intPool.put(big.NewInt(-1337))
-	evmInterpreter.intPool.put(big.NewInt(-1337))
-	evmInterpreter.intPool.put(big.NewInt(-1337))
 
 	for i, test := range tests {
-		x := new(big.Int).SetBytes(common.Hex2Bytes(test.X))
+		x := new(uint256.Int).SetBytes(common.Hex2Bytes(test.X))
-		y := new(big.Int).SetBytes(common.Hex2Bytes(test.Y))
+		y := new(uint256.Int).SetBytes(common.Hex2Bytes(test.Y))
-		expected := new(big.Int).SetBytes(common.Hex2Bytes(test.Expected))
+		expected := new(uint256.Int).SetBytes(common.Hex2Bytes(test.Expected))
 		stack.push(x)
 		stack.push(y)
 		opFn(&pc, evmInterpreter, &callCtx{nil, stack, rstack, nil})
+		if len(stack.data) != 1 {
+			t.Errorf("Expected one item on stack after %v, got %d: ", name, len(stack.data))
+		}
 		actual := stack.pop()
 
 		if actual.Cmp(expected) != 0 {
 			t.Errorf("Testcase %v %d, %v(%x, %x): expected  %x, got %x", name, i, name, x, y, expected, actual)
 		}
-		// Check pool usage
-		// 1.pool is not allowed to contain anything on the stack
-		// 2.pool is not allowed to contain the same pointers twice
-		if evmInterpreter.intPool.pool.len() > 0 {
-
-			poolvals := make(map[*big.Int]struct{})
-			poolvals[actual] = struct{}{}
-
-			for evmInterpreter.intPool.pool.len() > 0 {
-				key := evmInterpreter.intPool.get()
-				if _, exist := poolvals[key]; exist {
-					t.Errorf("Testcase %v %d, pool contains double-entry", name, i)
 	}
-				poolvals[key] = struct{}{}
-			}
-		}
-	}
-	poolOfIntPools.put(evmInterpreter.intPool)
 }
 
 func TestByteOp(t *testing.T) {
@@ -209,6 +190,44 @@ func TestSAR(t *testing.T) {
 	testTwoOperandOp(t, tests, opSAR, "sar")
 }
 
+func TestAddMod(t *testing.T) {
+	var (
+		env            = NewEVM(Context{}, nil, params.TestChainConfig, Config{})
+		stack          = newstack()
+		evmInterpreter = NewEVMInterpreter(env, env.vmConfig)
+		pc             = uint64(0)
+	)
+	tests := []struct {
+		x        string
+		y        string
+		z        string
+		expected string
+	}{
+		{"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+			"fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe",
+			"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
+			"fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe",
+		},
+	}
+	// x + y = 0x1fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd
+	// in 256 bit repr, fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffd
+
+	for i, test := range tests {
+		x := new(uint256.Int).SetBytes(common.Hex2Bytes(test.x))
+		y := new(uint256.Int).SetBytes(common.Hex2Bytes(test.y))
+		z := new(uint256.Int).SetBytes(common.Hex2Bytes(test.z))
+		expected := new(uint256.Int).SetBytes(common.Hex2Bytes(test.expected))
+		stack.push(z)
+		stack.push(y)
+		stack.push(x)
+		opAddmod(&pc, evmInterpreter, &callCtx{nil, stack, nil, nil})
+		actual := stack.pop()
+		if actual.Cmp(expected) != 0 {
+			t.Errorf("Testcase %d, expected  %x, got %x", i, expected, actual)
+		}
+	}
+}
+
 // getResult is a convenience function to generate the expected values
 func getResult(args []*twoOperandParams, opFn executionFunc) []TwoOperandTestcase {
 	var (
@@ -217,11 +236,10 @@ func getResult(args []*twoOperandParams, opFn executionFunc) []TwoOperandTestcas
 		pc            = uint64(0)
 		interpreter   = env.interpreter.(*EVMInterpreter)
 	)
-	interpreter.intPool = poolOfIntPools.get()
 	result := make([]TwoOperandTestcase, len(args))
 	for i, param := range args {
-		x := new(big.Int).SetBytes(common.Hex2Bytes(param.x))
+		x := new(uint256.Int).SetBytes(common.Hex2Bytes(param.x))
-		y := new(big.Int).SetBytes(common.Hex2Bytes(param.y))
+		y := new(uint256.Int).SetBytes(common.Hex2Bytes(param.y))
 		stack.push(x)
 		stack.push(y)
 		opFn(&pc, interpreter, &callCtx{nil, stack, rstack, nil})
@@ -269,7 +287,6 @@ func opBenchmark(bench *testing.B, op executionFunc, args ...string) {
 	)
 
 	env.interpreter = evmInterpreter
-	evmInterpreter.intPool = poolOfIntPools.get()
 	// convert args
 	byteArgs := make([][]byte, len(args))
 	for i, arg := range args {
@@ -279,13 +296,13 @@ func opBenchmark(bench *testing.B, op executionFunc, args ...string) {
 	bench.ResetTimer()
 	for i := 0; i < bench.N; i++ {
 		for _, arg := range byteArgs {
-			a := new(big.Int).SetBytes(arg)
+			a := new(uint256.Int)
+			a.SetBytes(arg)
 			stack.push(a)
 		}
 		op(&pc, evmInterpreter, &callCtx{nil, stack, rstack, nil})
 		stack.pop()
 	}
-	poolOfIntPools.put(evmInterpreter.intPool)
 }
 
 func BenchmarkOpAdd64(b *testing.B) {
@@ -505,21 +522,19 @@ func TestOpMstore(t *testing.T) {
 	)
 
 	env.interpreter = evmInterpreter
-	evmInterpreter.intPool = poolOfIntPools.get()
 	mem.Resize(64)
 	pc := uint64(0)
 	v := "abcdef00000000000000abba000000000deaf000000c0de00100000000133700"
-	stack.pushN(new(big.Int).SetBytes(common.Hex2Bytes(v)), big.NewInt(0))
+	stack.pushN(*new(uint256.Int).SetBytes(common.Hex2Bytes(v)), *new(uint256.Int))
 	opMstore(&pc, evmInterpreter, &callCtx{mem, stack, rstack, nil})
 	if got := common.Bytes2Hex(mem.GetCopy(0, 32)); got != v {
 		t.Fatalf("Mstore fail, got %v, expected %v", got, v)
 	}
-	stack.pushN(big.NewInt(0x1), big.NewInt(0))
+	stack.pushN(*new(uint256.Int).SetUint64(0x1), *new(uint256.Int))
 	opMstore(&pc, evmInterpreter, &callCtx{mem, stack, rstack, nil})
 	if common.Bytes2Hex(mem.GetCopy(0, 32)) != "0000000000000000000000000000000000000000000000000000000000000001" {
 		t.Fatalf("Mstore failed to overwrite previous value")
 	}
-	poolOfIntPools.put(evmInterpreter.intPool)
 }
 
 func BenchmarkOpMstore(bench *testing.B) {
@@ -531,18 +546,16 @@ func BenchmarkOpMstore(bench *testing.B) {
 	)
 
 	env.interpreter = evmInterpreter
-	evmInterpreter.intPool = poolOfIntPools.get()
 	mem.Resize(64)
 	pc := uint64(0)
-	memStart := big.NewInt(0)
+	memStart := new(uint256.Int)
-	value := big.NewInt(0x1337)
+	value := new(uint256.Int).SetUint64(0x1337)
 
 	bench.ResetTimer()
 	for i := 0; i < bench.N; i++ {
-		stack.pushN(value, memStart)
+		stack.pushN(*value, *memStart)
 		opMstore(&pc, evmInterpreter, &callCtx{mem, stack, rstack, nil})
 	}
-	poolOfIntPools.put(evmInterpreter.intPool)
 }
 
 func BenchmarkOpSHA3(bench *testing.B) {
@@ -553,17 +566,15 @@ func BenchmarkOpSHA3(bench *testing.B) {
 		evmInterpreter = NewEVMInterpreter(env, env.vmConfig)
 	)
 	env.interpreter = evmInterpreter
-	evmInterpreter.intPool = poolOfIntPools.get()
 	mem.Resize(32)
 	pc := uint64(0)
-	start := big.NewInt(0)
+	start := uint256.NewInt()
 
 	bench.ResetTimer()
 	for i := 0; i < bench.N; i++ {
-		stack.pushN(big.NewInt(32), start)
+		stack.pushN(*uint256.NewInt().SetUint64(32), *start)
 		opSha3(&pc, evmInterpreter, &callCtx{mem, stack, rstack, nil})
 	}
-	poolOfIntPools.put(evmInterpreter.intPool)
 }
 
 func TestCreate2Addreses(t *testing.T) {
@@ -637,6 +648,5 @@ func TestCreate2Addreses(t *testing.T) {
 		if !bytes.Equal(expected.Bytes(), address.Bytes()) {
 			t.Errorf("test %d: expected %s, got %s", i, expected.String(), address.String())
 		}
-
 	}
 }

core/vm/int_pool_verifier.go

@@ -1,31 +0,0 @@
-// Copyright 2017 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
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-// +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))
-		}
-	}
-}

core/vm/int_pool_verifier_empty.go

@@ -1,23 +0,0 @@
-// Copyright 2017 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
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-// +build !VERIFY_EVM_INTEGER_POOL
-
-package vm
-
-const verifyPool = false
-
-func verifyIntegerPool(ip *intPool) {}

core/vm/interpreter.go

@@ -84,8 +84,6 @@ type EVMInterpreter struct {
 	evm *EVM
 	cfg Config
 
-	intPool *intPool
-
 	hasher    keccakState // Keccak256 hasher instance shared across opcodes
 	hasherBuf common.Hash // Keccak256 hasher result array shared aross opcodes
 
@@ -141,13 +139,6 @@ func NewEVMInterpreter(evm *EVM, cfg Config) *EVMInterpreter {
 // considered a revert-and-consume-all-gas operation except for
 // ErrExecutionReverted which means revert-and-keep-gas-left.
 func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (ret []byte, err error) {
-	if in.intPool == nil {
-		in.intPool = poolOfIntPools.get()
-		defer func() {
-			poolOfIntPools.put(in.intPool)
-			in.intPool = nil
-		}()
-	}
 
 	// Increment the call depth which is restricted to 1024
 	in.evm.depth++
@@ -193,9 +184,6 @@ func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (
 	)
 	contract.Input = input
 
-	// Reclaim the stack as an int pool when the execution stops
-	defer func() { in.intPool.put(stack.data...) }()
-
 	if in.cfg.Debug {
 		defer func() {
 			if err != nil {
@@ -290,11 +278,6 @@ func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (
 
 		// execute the operation
 		res, err = operation.execute(&pc, in, callContext)
-		// 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(in.intPool)
-		}
 		// if the operation clears the return data (e.g. it has returning data)
 		// set the last return to the result of the operation.
 		if operation.returns {

core/vm/intpool.go

@@ -1,117 +0,0 @@
-// Copyright 2017 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
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package vm
-
-import (
-	"math/big"
-	"sync"
-)
-
-var checkVal = big.NewInt(-42)
-
-const poolLimit = 256
-
-// 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()}
-}
-
-// get retrieves a big int from the pool, allocating one if the pool is empty.
-// Note, the returned int's value is arbitrary and will not be zeroed!
-func (p *intPool) get() *big.Int {
-	if p.pool.len() > 0 {
-		return p.pool.pop()
-	}
-	return new(big.Int)
-}
-
-// getZero retrieves a big int from the pool, setting it to zero or allocating
-// a new one if the pool is empty.
-func (p *intPool) getZero() *big.Int {
-	if p.pool.len() > 0 {
-		return p.pool.pop().SetUint64(0)
-	}
-	return new(big.Int)
-}
-
-// putOne returns an allocated big int to the pool to be later reused by get calls.
-// Note, the values as saved as is; neither put nor get zeroes the ints out!
-// As opposed to 'put' with variadic args, this method becomes inlined by the
-// go compiler
-func (p *intPool) putOne(i *big.Int) {
-	if len(p.pool.data) > poolLimit {
-		return
-	}
-	p.pool.push(i)
-}
-
-// put returns an allocated big int to the pool to be later reused by get calls.
-// Note, the values as saved as is; neither put nor get zeroes the ints out!
-func (p *intPool) put(is ...*big.Int) {
-	if len(p.pool.data) > poolLimit {
-		return
-	}
-	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)
-	}
-}
-
-// The intPool pool's default capacity
-const poolDefaultCap = 25
-
-// intPoolPool manages a pool of intPools.
-type intPoolPool struct {
-	pools []*intPool
-	lock  sync.Mutex
-}
-
-var poolOfIntPools = &intPoolPool{
-	pools: make([]*intPool, 0, poolDefaultCap),
-}
-
-// get is looking for an available pool to return.
-func (ipp *intPoolPool) get() *intPool {
-	ipp.lock.Lock()
-	defer ipp.lock.Unlock()
-
-	if len(poolOfIntPools.pools) > 0 {
-		ip := ipp.pools[len(ipp.pools)-1]
-		ipp.pools = ipp.pools[:len(ipp.pools)-1]
-		return ip
-	}
-	return newIntPool()
-}
-
-// put a pool that has been allocated with get.
-func (ipp *intPoolPool) put(ip *intPool) {
-	ipp.lock.Lock()
-	defer ipp.lock.Unlock()
-
-	if len(ipp.pools) < cap(ipp.pools) {
-		ipp.pools = append(ipp.pools, ip)
-	}
-}

core/vm/intpool_test.go

@@ -1,55 +0,0 @@
-// Copyright 2018 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
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-package vm
-
-import (
-	"testing"
-)
-
-func TestIntPoolPoolGet(t *testing.T) {
-	poolOfIntPools.pools = make([]*intPool, 0, poolDefaultCap)
-
-	nip := poolOfIntPools.get()
-	if nip == nil {
-		t.Fatalf("Invalid pool allocation")
-	}
-}
-
-func TestIntPoolPoolPut(t *testing.T) {
-	poolOfIntPools.pools = make([]*intPool, 0, poolDefaultCap)
-
-	nip := poolOfIntPools.get()
-	if len(poolOfIntPools.pools) != 0 {
-		t.Fatalf("Pool got added to list when none should have been")
-	}
-
-	poolOfIntPools.put(nip)
-	if len(poolOfIntPools.pools) == 0 {
-		t.Fatalf("Pool did not get added to list when one should have been")
-	}
-}
-
-func TestIntPoolPoolReUse(t *testing.T) {
-	poolOfIntPools.pools = make([]*intPool, 0, poolDefaultCap)
-	nip := poolOfIntPools.get()
-	poolOfIntPools.put(nip)
-	poolOfIntPools.get()
-
-	if len(poolOfIntPools.pools) != 0 {
-		t.Fatalf("Invalid number of pools. Got %d, expected %d", len(poolOfIntPools.pools), 0)
-	}
-}

core/vm/logger.go

@@ -159,8 +159,8 @@ func (l *StructLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost ui
 	// it in the local storage container.
 	if op == SSTORE && stack.len() >= 2 {
 		var (
-			value   = common.BigToHash(stack.data[stack.len()-2])
+			value   = common.Hash(stack.data[stack.len()-2].Bytes32())
-			address = common.BigToHash(stack.data[stack.len()-1])
+			address = common.Hash(stack.data[stack.len()-1].Bytes32())
 		)
 		l.changedValues[contract.Address()][address] = value
 	}
@@ -175,7 +175,7 @@ func (l *StructLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost ui
 	if !l.cfg.DisableStack {
 		stck = make([]*big.Int, len(stack.Data()))
 		for i, item := range stack.Data() {
-			stck[i] = new(big.Int).Set(item)
+			stck[i] = new(big.Int).Set(item.ToBig())
 		}
 	}
 	// Copy a snapshot of the current storage to a new container

core/vm/logger_json.go

@@ -62,7 +62,12 @@ func (l *JSONLogger) CaptureState(env *EVM, pc uint64, op OpCode, gas, cost uint
 		log.Memory = memory.Data()
 	}
 	if !l.cfg.DisableStack {
-		log.Stack = stack.Data()
+		//TODO(@holiman) improve this
+		logstack := make([]*big.Int, len(stack.Data()))
+		for i, item := range stack.Data() {
+			logstack[i] = item.ToBig()
+		}
+		log.Stack = logstack
 		log.ReturnStack = rStack.data
 	}
 	return l.encoder.Encode(log)

core/vm/logger_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/params"
+	"github.com/holiman/uint256"
 )
 
 type dummyContractRef struct {
@@ -57,8 +58,8 @@ func TestStoreCapture(t *testing.T) {
 		rstack   = newReturnStack()
 		contract = NewContract(&dummyContractRef{}, &dummyContractRef{}, new(big.Int), 0)
 	)
-	stack.push(big.NewInt(1))
+	stack.push(uint256.NewInt().SetUint64(1))
-	stack.push(big.NewInt(0))
+	stack.push(uint256.NewInt())
 	var index common.Hash
 	logger.CaptureState(env, 0, SSTORE, 0, 0, mem, stack, rstack, contract, 0, nil)
 	if len(logger.changedValues[contract.Address()]) == 0 {

core/vm/memory.go

@@ -18,9 +18,8 @@ package vm
 
 import (
 	"fmt"
-	"math/big"
 
-	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/holiman/uint256"
 )
 
 // Memory implements a simple memory model for the ethereum virtual machine.
@@ -50,7 +49,7 @@ func (m *Memory) Set(offset, size uint64, value []byte) {
 
 // Set32 sets the 32 bytes starting at offset to the value of val, left-padded with zeroes to
 // 32 bytes.
-func (m *Memory) Set32(offset uint64, val *big.Int) {
+func (m *Memory) Set32(offset uint64, val *uint256.Int) {
 	// length of store may never be less than offset + size.
 	// The store should be resized PRIOR to setting the memory
 	if offset+32 > uint64(len(m.store)) {
@@ -59,7 +58,7 @@ func (m *Memory) Set32(offset uint64, val *big.Int) {
 	// Zero the memory area
 	copy(m.store[offset:offset+32], []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0})
 	// Fill in relevant bits
-	math.ReadBits(val, m.store[offset:offset+32])
+	val.WriteToSlice(m.store[offset:])
 }
 
 // Resize resizes the memory to size

core/vm/stack.go

@@ -18,36 +18,36 @@ package vm
 
 import (
 	"fmt"
-	"math/big"
+
+	"github.com/holiman/uint256"
 )
 
 // Stack is an object for basic stack operations. Items popped to the stack are
 // expected to be changed and modified. stack does not take care of adding newly
 // initialised objects.
 type Stack struct {
-	data []*big.Int
+	data []uint256.Int
 }
 
 func newstack() *Stack {
-	return &Stack{data: make([]*big.Int, 0, 1024)}
+	return &Stack{data: make([]uint256.Int, 0, 16)}
 }
 
-// Data returns the underlying big.Int array.
+// Data returns the underlying uint256.Int array.
-func (st *Stack) Data() []*big.Int {
+func (st *Stack) Data() []uint256.Int {
 	return st.data
 }
 
-func (st *Stack) push(d *big.Int) {
+func (st *Stack) push(d *uint256.Int) {
 	// NOTE push limit (1024) is checked in baseCheck
-	//stackItem := new(big.Int).Set(d)
+	st.data = append(st.data, *d)
-	//st.data = append(st.data, stackItem)
-	st.data = append(st.data, d)
 }
-func (st *Stack) pushN(ds ...*big.Int) {
+func (st *Stack) pushN(ds ...uint256.Int) {
+	// FIXME: Is there a way to pass args by pointers.
 	st.data = append(st.data, ds...)
 }
 
-func (st *Stack) pop() (ret *big.Int) {
+func (st *Stack) pop() (ret uint256.Int) {
 	ret = st.data[len(st.data)-1]
 	st.data = st.data[:len(st.data)-1]
 	return
@@ -61,17 +61,17 @@ func (st *Stack) swap(n int) {
 	st.data[st.len()-n], st.data[st.len()-1] = st.data[st.len()-1], st.data[st.len()-n]
 }
 
-func (st *Stack) dup(pool *intPool, n int) {
+func (st *Stack) dup(n int) {
-	st.push(pool.get().Set(st.data[st.len()-n]))
+	st.push(&st.data[st.len()-n])
 }
 
-func (st *Stack) peek() *big.Int {
+func (st *Stack) peek() *uint256.Int {
-	return st.data[st.len()-1]
+	return &st.data[st.len()-1]
 }
 
 // Back returns the n'th item in stack
-func (st *Stack) Back(n int) *big.Int {
+func (st *Stack) Back(n int) *uint256.Int {
-	return st.data[st.len()-n-1]
+	return &st.data[st.len()-n-1]
 }
 
 // Print dumps the content of the stack

eth/tracers/tracer.go

@@ -162,7 +162,7 @@ func (sw *stackWrapper) peek(idx int) *big.Int {
 		log.Warn("Tracer accessed out of bound stack", "size", len(sw.stack.Data()), "index", idx)
 		return new(big.Int)
 	}
-	return sw.stack.Data()[len(sw.stack.Data())-idx-1]
+	return sw.stack.Back(idx).ToBig()
 }
 
 // pushObject assembles a JSVM object wrapping a swappable stack and pushes it

go.mod

@@ -31,6 +31,7 @@ require (
 	github.com/gorilla/websocket v1.4.1-0.20190629185528-ae1634f6a989
 	github.com/graph-gophers/graphql-go v0.0.0-20191115155744-f33e81362277
 	github.com/hashicorp/golang-lru v0.5.4
+	github.com/holiman/uint256 v1.0.0
 	github.com/huin/goupnp v1.0.0
 	github.com/influxdata/influxdb v1.2.3-0.20180221223340-01288bdb0883
 	github.com/jackpal/go-nat-pmp v1.0.2-0.20160603034137-1fa385a6f458

go.sum

@@ -93,6 +93,10 @@ github.com/graph-gophers/graphql-go v0.0.0-20191115155744-f33e81362277 h1:E0whKx
 github.com/graph-gophers/graphql-go v0.0.0-20191115155744-f33e81362277/go.mod h1:9CQHMSxwO4MprSdzoIEobiHpoLtHm77vfxsvsIN5Vuc=
 github.com/hashicorp/golang-lru v0.5.4 h1:YDjusn29QI/Das2iO9M0BHnIbxPeyuCHsjMW+lJfyTc=
 github.com/hashicorp/golang-lru v0.5.4/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
+github.com/holiman/uint256 v0.0.0-20200319132535-a4d16d7dba8d h1:GHyibjawOjlV6CVRfc7nAD2fFiwadHU2p87viNQtG/c=
+github.com/holiman/uint256 v0.0.0-20200319132535-a4d16d7dba8d/go.mod h1:y4ga/t+u+Xwd7CpDgZESaRcWy0I7XMlTMA25ApIH5Jw=
+github.com/holiman/uint256 v1.0.0 h1:GV654hUWgO9gVQwgjMyup5bkUCWI9t87+LSjB9fAo5c=
+github.com/holiman/uint256 v1.0.0/go.mod h1:y4ga/t+u+Xwd7CpDgZESaRcWy0I7XMlTMA25ApIH5Jw=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/huin/goupnp v1.0.0 h1:wg75sLpL6DZqwHQN6E1Cfk6mtfzS45z8OV+ic+DtHRo=