def test_8xy2_leaves_other_registers_alone(self, x, y):
"""8xy2 leaves registers other than VX and VY alone"""
vm = VM()
vm.v_registers[x] = 0b10101010
vm.v_registers[y] = 0b01010101
load_and_execute_instruction(vm, 0x8002, x=x, y=y)
assert other_registers_untouched(vm, (x, y))
def test_8xy0_leaves_original_alone(self, x, y):
"""8xy0 leaves VY alone"""
vm = VM()
vm.v_registers[x] = 2
vm.v_registers[y] = 3
load_and_execute_instruction(vm, 0x8000, x=x, y=y)
assert other_registers_untouched(vm, {x, y})
def test_8xye_leaves_other_registers_alone_unless_theyre_vf(self, x, y):
"""8xy6 leaves registers other than VX alone except for VF"""
vm = VM()
vm.v_registers[x] = 2
vm.v_registers[y] = 1
load_and_execute_instruction(vm, 0x800E, x=x, y=y)
# make sure we don't check VF since it should always be set
touched = {x, 0xF}
assert other_registers_untouched(vm, touched)