From febf163097c4cd489c13acf8fd98a9e79738153a Mon Sep 17 00:00:00 2001
From: smblucker <smblucker@outlook.com>
Date: Mon, 14 May 2018 16:40:30 -0400
Subject: [PATCH] Implementing shl, shr, and sar opcodes

Signed-off-by: smblucker <smblucker@outlook.com>
---
 binary/integer.go        |   1 +
 execution/evm/vm.go      |  44 +++-
 execution/evm/vm_test.go | 470 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 514 insertions(+), 1 deletion(-)

diff --git a/binary/integer.go b/binary/integer.go
index a00c0705..cd57bf3a 100644
--- a/binary/integer.go
+++ b/binary/integer.go
@@ -22,6 +22,7 @@ import (
 )
 
 var big1 = big.NewInt(1)
+var Big256 = big.NewInt(256)
 var tt256 = new(big.Int).Lsh(big1, 256)
 var tt256m1 = new(big.Int).Sub(new(big.Int).Lsh(big1, 256), big1)
 var tt255 = new(big.Int).Lsh(big1, 255)
diff --git a/execution/evm/vm.go b/execution/evm/vm.go
index aca67567..c0191bf6 100644
--- a/execution/evm/vm.go
+++ b/execution/evm/vm.go
@@ -496,6 +496,48 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
 			stack.Push64(int64(res))
 			vm.Debugf(" => 0x%X\n", res)
 
+		case SHL: //0x1B
+			shift, x := stack.PopBigInt(), stack.PopBigInt()
+
+			if shift.Cmp(Big256) >= 0 {
+				reset := big.NewInt(0)
+				stack.PushBigInt(reset)
+				vm.Debugf(" %v << %v = %v\n", x, shift, reset)
+			} else {
+				shiftedValue := x.Lsh(x, uint(shift.Uint64()))
+				stack.PushBigInt(shiftedValue)
+				vm.Debugf(" %v << %v = %v\n", x, shift, shiftedValue)
+			}
+
+		case SHR: //0x1C
+			shift, x := stack.PopBigInt(), stack.PopBigInt()
+
+			if shift.Cmp(Big256) >= 0 {
+				reset := big.NewInt(0)
+				stack.PushBigInt(reset)
+				vm.Debugf(" %v << %v = %v\n", x, shift, reset)
+			} else {
+				shiftedValue := x.Rsh(x, uint(shift.Uint64()))
+				stack.PushBigInt(shiftedValue)
+				vm.Debugf(" %v << %v = %v\n", x, shift, shiftedValue)
+			}
+
+		case SAR: //0x1D
+			shift, x := stack.PopBigInt(), stack.PopBigIntSigned()
+
+			if shift.Cmp(Big256) >= 0 {
+				reset := big.NewInt(0)
+				if x.Sign() < 0 {
+					reset.SetInt64(-1)
+				}
+				stack.PushBigInt(reset)
+				vm.Debugf(" %v << %v = %v\n", x, shift, reset)
+			} else {
+				shiftedValue := x.Rsh(x, uint(shift.Uint64()))
+				stack.PushBigInt(shiftedValue)
+				vm.Debugf(" %v << %v = %v\n", x, shift, shiftedValue)
+			}
+
 		case SHA3: // 0x20
 			if useGasNegative(gas, GasSha3, &err) {
 				return nil, err
@@ -1111,7 +1153,7 @@ func (vm *VM) call(caller acm.Account, callee acm.MutableAccount, code, input []
 		case STOP: // 0x00
 			return nil, nil
 
-		case STATICCALL, SHL, SHR, SAR:
+		case STATICCALL:
 			return nil, fmt.Errorf("%s not yet implemented", op.Name())
 		default:
 			vm.Debugf("(pc) %-3v Unknown opcode %X\n", pc, op)
diff --git a/execution/evm/vm_test.go b/execution/evm/vm_test.go
index ffa5454c..b885d266 100644
--- a/execution/evm/vm_test.go
+++ b/execution/evm/vm_test.go
@@ -95,6 +95,476 @@ func TestVM(t *testing.T) {
 	}
 }
 
+func TestSHL(t *testing.T) {
+	ourVm := NewVM(newAppState(), newParams(), acm.ZeroAddress, nil, logger)
+	account1 := newAccount(1)
+	account2 := newAccount(1, 0, 1)
+
+	var gas uint64 = 100000
+
+	//Shift left 0
+	bytecode := MustSplice(PUSH1, 0x01, PUSH1, 0x00, SHL, return1())
+	output, err := ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value := []uint8([]byte{0x1})
+	expected := LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift left 0
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0x00, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift left 1
+	bytecode = MustSplice(PUSH1, 0x01, PUSH1, 0x01, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x2})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift left 1
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0x01, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift left 1
+	bytecode = MustSplice(PUSH32, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0x01, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift left 255
+	bytecode = MustSplice(PUSH1, 0x01, PUSH1, 0xFF, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x80})
+	expected = RightPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift left 255
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0xFF, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x80})
+	expected = RightPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift left 256 (overflow)
+	bytecode = MustSplice(PUSH1, 0x01, PUSH2, 0x01, 0x00, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift left 256 (overflow)
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH2, 0x01, 0x00, SHL,
+		return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift left 257 (overflow)
+	bytecode = MustSplice(PUSH1, 0x01, PUSH2, 0x01, 0x01, SHL, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+}
+
+func TestSHR(t *testing.T) {
+	ourVm := NewVM(newAppState(), newParams(), acm.ZeroAddress, nil, logger)
+	account1 := newAccount(1)
+	account2 := newAccount(1, 0, 1)
+
+	var gas uint64 = 100000
+
+	//Shift right 0
+	bytecode := MustSplice(PUSH1, 0x01, PUSH1, 0x00, SHR, return1())
+	output, err := ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value := []uint8([]byte{0x1})
+	expected := LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift right 0
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0x00, SHR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift right 1
+	bytecode = MustSplice(PUSH1, 0x01, PUSH1, 0x01, SHR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift right 1
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH1, 0x01, SHR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x40})
+	expected = RightPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift right 1
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0x01, SHR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift right 255
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH1, 0xFF, SHR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x1})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift right 255
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0xFF, SHR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x1})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift right 256 (underflow)
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH2, 0x01, 0x00, SHR,
+		return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift right 256 (underflow)
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH2, 0x01, 0x00, SHR,
+		return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift right 257 (underflow)
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH2, 0x01, 0x01, SHR,
+		return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+}
+
+func TestSAR(t *testing.T) {
+	ourVm := NewVM(newAppState(), newParams(), acm.ZeroAddress, nil, logger)
+	account1 := newAccount(1)
+	account2 := newAccount(1, 0, 1)
+
+	var gas uint64 = 100000
+
+	//Shift arith right 0
+	bytecode := MustSplice(PUSH1, 0x01, PUSH1, 0x00, SAR, return1())
+	output, err := ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value := []uint8([]byte{0x1})
+	expected := LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative arith shift right 0
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0x00, SAR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift arith right 1
+	bytecode = MustSplice(PUSH1, 0x01, PUSH1, 0x01, SAR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift arith right 1
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH1, 0x01, SAR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0xc0})
+	expected = RightPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift arith right 1
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0x01, SAR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift arith right 255
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH1, 0xFF, SAR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift arith right 255
+	bytecode = MustSplice(PUSH32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0xFF, SAR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift arith right 255
+	bytecode = MustSplice(PUSH32, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH1, 0xFF, SAR, return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = RightPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift arith right 256 (reset)
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH2, 0x01, 0x00, SAR,
+		return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Alternative shift arith right 256 (reset)
+	bytecode = MustSplice(PUSH32, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, PUSH2, 0x01, 0x00, SAR,
+		return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	value = []uint8([]byte{0x00})
+	expected = LeftPadBytes(value, 32)
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Shift arith right 257 (reset)
+	bytecode = MustSplice(PUSH32, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, PUSH2, 0x01, 0x01, SAR,
+		return1())
+	output, err = ourVm.Call(account1, account2, bytecode, []byte{}, 0, &gas)
+	expected = []uint8([]byte{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF})
+
+	assert.Equal(t, expected, output)
+
+	t.Logf("Result: %v == %v\n", output, expected)
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+}
+
 //Test attempt to jump to bad destination (position 16)
 func TestJumpErr(t *testing.T) {
 	ourVm := NewVM(newAppState(), newParams(), acm.ZeroAddress, nil, logger)
-- 
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