def test_MUL_resulting_in_signed_negative_overflow(vm):
vm.registers[2] = to_u16(-400)
vm.registers[3] = to_u16(-200)
helper(vm, "MUL(R1, R2, R3)")
assert vm.registers[1] == 14464
assert vm.flag_carry
assert vm.flag_overflow
def test_ADD_resulting_in_negative(vm):
vm.registers[2] = to_u16(-14)
vm.registers[3] = 8
helper(vm, "ADD(R1, R2, R3)")
assert vm.registers[1] == to_u16(-6)
assert vm.flag_sign
assert not vm.flag_zero
def test_AND_does_not_set_other_flags(vm):
vm.registers[2] = to_u16(-1)
vm.registers[3] = to_u16(-1)
helper(vm, "AND(R1, R2, R3)")
assert vm.registers[1] == to_u16(-1)
assert not vm.flag_carry
assert not vm.flag_overflow
def test_XOR_does_not_set_other_flags(vm):
vm.registers[2] = 0
vm.registers[3] = to_u16(-37)
helper(vm, "XOR(R1, R2, R3)")
assert vm.registers[1] == to_u16(-37)
assert not vm.flag_carry
assert not vm.flag_overflow
def test_ADD_resulting_in_negative_overflow(vm):
vm.registers[2] = to_u16(-32768)
vm.registers[3] = to_u16(-32768)
helper(vm, "ADD(R1, R2, R3)")
assert vm.registers[1] == 0
assert vm.flag_overflow
assert vm.flag_carry
def test_SUB_with_no_carry_block_and_no_borrow(vm):
vm.flag_carry = True
vm.registers[2] = to_u16(-64)
vm.registers[3] = 22
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == to_u16(-86)
assert vm.flag_carry
def test_LOAD_sets_sign_flag(vm):
vm.memory[4] = to_u16(-2)
vm.registers[2] = 4
helper(vm, "LOAD(R1, 0, R2)")
assert vm.registers[1] == to_u16(-2)
assert not vm.flag_zero
assert vm.flag_sign
def test_SUB_resulting_in_maximum_positive_overflow(vm):
vm.flag_carry_block = True
vm.registers[2] = 32767
vm.registers[3] = to_u16(-32768)
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == to_u16(-1)
assert not vm.flag_carry
assert vm.flag_overflow
def test_SUB_with_two_negatives(vm):
vm.flag_carry_block = True
vm.registers[2] = to_u16(-20)
vm.registers[3] = to_u16(-40)
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == 20
assert vm.flag_carry
assert not vm.flag_overflow
def test_SUB_resulting_in_big_positive_overflow(vm):
vm.flag_carry_block = True
vm.registers[2] = 27500
vm.registers[3] = to_u16(-7040)
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == to_u16(-30996)
assert not vm.flag_carry
assert vm.flag_overflow
def test_SUB_resulting_in_zero(vm):
vm.flag_carry_block = True
vm.registers[2] = to_u16(-37)
vm.registers[3] = to_u16(-37)
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == 0
assert not vm.flag_sign
assert vm.flag_zero
def test_SUB_resulting_in_negative(vm):
vm.flag_carry_block = True
vm.registers[2] = to_u16(-64)
vm.registers[3] = 22
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == to_u16(-86)
assert vm.flag_sign
assert not vm.flag_zero
def test_OR_does_not_clear_other_flags(vm):
vm.flag_carry = True
vm.flag_overflow = True
vm.registers[2] = to_u16(-1)
vm.registers[3] = to_u16(-1)
helper(vm, "OR(R1, R2, R3)")
assert vm.flag_carry
assert vm.flag_overflow
def test_LSL_shifts_out_carry_when_blocked(vm):
vm.flag_carry_block = True
vm.registers[2] = to_u16(-20000)
helper(vm, "LSL(R1, R2)")
assert vm.flag_carry
def test_DEC_ignores_incoming_carry(vm):
vm.flag_carry = True
helper(vm, "DEC(R8, 5)")
assert vm.registers[8] == to_u16(-5)
assert not vm.flag_carry
def test_ASL_shifts_out_carry_when_blocked(vm):
vm.registers[2] = to_u16(-20000)
helper(vm, "ASL(R1, R2)")
assert vm.flag_carry
assert vm.flag_overflow
def test_INC_sets_carry_flag(vm):
vm.registers[8] = to_u16(-1)
helper(vm, "INC(R8, 1)")
assert vm.flag_carry
assert not vm.flag_overflow
def test_arrays():
# Figure 6.2, p. 34
program = """\
DLABEL(ArrayOfSevenPrimes)
INTEGER(7)
INTEGER(2) INTEGER(3) INTEGER(5) INTEGER(7) DSKIP(1) INTEGER(13) INTEGER(17)
DLABEL(ArrayOfSevenSquaredPrimes)
DSKIP(8)
CBON()
SET(Rt, ArrayOfSevenPrimes)
SETLO(R1, 5)
ADD(Rt, Rt, R1)
SETLO(R1, 11)
STORE(R1, 0, Rt)
SET(R1, ArrayOfSevenPrimes)
SET(R2, ArrayOfSevenSquaredPrimes)
LOAD(R3, 0, R1)
STORE(R3, 0, R2)
LABEL(SquareNextOne)
DEC(R3, 1)
BL(NoMoreSquares)
INC(R1, 1)
INC(R2, 1)
LOAD(R4, 0, R1)
MUL(R4, R4, R4)
STORE(R4, 0, R2)
BR(SquareNextOne)
LABEL(NoMoreSquares)
HALT()
"""
vm = execute_program_helper(program)
assert vm.registers[1] == DEFAULT_DATA_START + 7
assert vm.registers[2] == DEFAULT_DATA_START + 15
assert vm.registers[3] == to_u16(-1)
assert vm.registers[4] == 289
assert vm.memory[DEFAULT_DATA_START] == 7
assert vm.memory[DEFAULT_DATA_START + 1] == 2
assert vm.memory[DEFAULT_DATA_START + 2] == 3
assert vm.memory[DEFAULT_DATA_START + 3] == 5
assert vm.memory[DEFAULT_DATA_START + 4] == 7
assert vm.memory[DEFAULT_DATA_START + 5] == 11
assert vm.memory[DEFAULT_DATA_START + 6] == 13
assert vm.memory[DEFAULT_DATA_START + 7] == 17
assert vm.memory[DEFAULT_DATA_START + 8] == 7
assert vm.memory[DEFAULT_DATA_START + 9] == 4
assert vm.memory[DEFAULT_DATA_START + 10] == 9
assert vm.memory[DEFAULT_DATA_START + 11] == 25
assert vm.memory[DEFAULT_DATA_START + 12] == 49
assert vm.memory[DEFAULT_DATA_START + 13] == 121
assert vm.memory[DEFAULT_DATA_START + 14] == 169
assert vm.memory[DEFAULT_DATA_START + 15] == 289
def test_INC_sets_sign_flag(vm):
vm.registers[1] = 32765
helper(vm, "INC(R1, 5)")
assert vm.registers[1] == to_u16(-32766)
assert not vm.flag_zero
assert vm.flag_sign
def test_INC_sets_zero_flag(vm):
vm.registers[7] = to_u16(-1)
helper(vm, "INC(R7, 1)")
assert vm.registers[7] == 0
assert vm.flag_zero
assert not vm.flag_sign
def test_DEC_sets_overflow_flag(vm):
vm.registers[8] = to_u16(-32768)
helper(vm, "DEC(R8, 5)")
assert vm.registers[8] == 32763
assert vm.flag_carry
assert vm.flag_overflow
def test_DEC_sets_sign_flag(vm):
vm.registers[1] = 1
helper(vm, "DEC(R1, 5)")
assert vm.registers[1] == to_u16(-4)
assert not vm.flag_zero
assert vm.flag_sign
def test_MUL_with_sign_flag_and_negative_result(vm):
vm.flag_sign = True
vm.registers[2] = 20000
vm.registers[3] = to_u16(-200)
helper(vm, "MUL(R1, R2, R3)")
assert vm.registers[1] == 0b1111111111000010
def test_LSL_with_negative_overflow(vm):
vm.registers[2] = to_u16(-20000)
helper(vm, "LSL(R1, R2)")
assert vm.registers[1] == 25536
assert vm.flag_carry
assert not vm.flag_overflow
def test_SUB_does_not_set_carry_for_equal_operands_with_no_incoming_carry(vm):
vm.registers[2] = 12
vm.registers[3] = 12
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == to_u16(-1)
assert not vm.flag_carry
def test_LSR_shifts_in_carry(vm):
vm.flag_carry = True
vm.registers[2] = 6
helper(vm, "LSR(R1, R2)")
assert vm.registers[1] == to_u16(-32765)
assert not vm.flag_carry
def test_ADD_resulting_in_big_overflow(vm):
vm.registers[2] = 32767
vm.registers[3] = 32767
helper(vm, "ADD(R1, R2, R3)")
assert vm.registers[1] == to_u16(-2)
assert vm.flag_overflow
assert not vm.flag_carry
def test_ADD_resulting_in_zero(vm):
vm.registers[2] = to_u16(-4)
vm.registers[3] = 4
helper(vm, "ADD(R1, R2, R3)")
assert vm.registers[1] == 0
assert not vm.flag_sign
assert vm.flag_zero
def test_MUL_resulting_in_signed_positive_overflow(vm):
vm.registers[2] = 17000
vm.registers[3] = 3
helper(vm, "MUL(R1, R2, R3)")
assert vm.registers[1] == to_u16(-14536)
assert not vm.flag_carry
assert vm.flag_overflow
def test_SUB_overflow_from_borrow(vm):
vm.registers[2] = to_u16(-32767)
vm.registers[3] = 1
helper(vm, "SUB(R1, R2, R3)")
assert vm.registers[1] == 32767
assert vm.flag_carry
assert vm.flag_overflow