TrueCloudLab/neoneo-go
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vm: use truncated division for Integers

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When divisor is negative, the result is truncated towards
zero.
This commit is contained in:
Evgenii Stratonikov 2020-03-17 15:45:53 +03:00
parent a87f849115
commit 4b44190485
2 changed files with 16 additions and 6 deletions
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2
pkg/vm/vm.go
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@ -776,7 +776,7 @@ func (v *VM) execute(ctx *Context, op opcode.Opcode, parameter []byte) (err erro
a := v.estack.Pop().BigInt() a := v.estack.Pop().BigInt()
v.checkBigIntSize(a) v.checkBigIntSize(a)
v.estack.PushVal(new(big.Int).Div(a, b)) v.estack.PushVal(new(big.Int).Quo(a, b))
case opcode.MUL: case opcode.MUL:
a := v.estack.Pop().BigInt() a := v.estack.Pop().BigInt()

16
pkg/vm/vm_test.go
View file

@ -832,11 +832,21 @@ func TestMULBigResult(t *testing.T) {
func TestDiv(t *testing.T) { func TestDiv(t *testing.T) {
prog := makeProgram(opcode.DIV) prog := makeProgram(opcode.DIV)
runCase := func(p, q, result int64) func(t *testing.T) {
return func(t *testing.T) {
vm := load(prog) vm := load(prog)
vm.estack.PushVal(4) vm.estack.PushVal(p)
vm.estack.PushVal(2) vm.estack.PushVal(q)
runVM(t, vm) runVM(t, vm)
assert.Equal(t, int64(2), vm.estack.Pop().BigInt().Int64()) assert.Equal(t, result, vm.estack.Pop().BigInt().Int64())
}
}
t.Run("positive/positive", runCase(5, 2, 2))
t.Run("positive/negative", runCase(5, -2, -2))
t.Run("negative/positive", runCase(-5, 2, -2))
t.Run("negative/negative", runCase(-5, -2, 2))
} }
func TestSub(t *testing.T) { func TestSub(t *testing.T) {