def binary_comp(comp):
return concat(
decr_sp(),
load_stack_top_into_d(),
decr_sp(),
['@SP', 'A=M', 'D=M-D'],
if_else(
comparator=comp,
true_block=['@SP', 'A=M',
'M=-1'], # recall: in HW -1 represents true, 0 false
false_block=['@SP', 'A=M', 'M=0']),
incr_sp())
def func_call(func_label, nargs):
return_address = get_func_end_label(func_label)
return concat(
# push dummy value onto stack to allocate space for return value when nargs = 0
load_constant_into_d(0),
push_d_onto_stack(),
incr_sp(),
push_stack_frame(return_address),
set_segment_to_sp('ARG'),
concat(load_constant_into_d(5), ['@ARG', 'M=M-D']),
concat(load_constant_into_d(int(nargs) + 1), ['@ARG', 'M=M-D']),
set_segment_to_sp('LCL'),
goto(func_label),
label(return_address),
)
def unary_op(op):
return concat(decr_sp(), ['@SP', 'A=M', f'M={op}M'], incr_sp())
def binary_op(op):
return concat(decr_sp(), load_stack_top_into_d(), decr_sp(),
['@SP', 'A=M', f'M=M{op}D'], incr_sp())
def push_return_address(return_address):
return concat(load_constant_into_d(return_address), push_d_onto_stack(),
incr_sp())
def push_segment_pointer(segment):
return concat([f'@{segment}', 'D=M'], push_d_onto_stack(), incr_sp())
def push_static(_, index):
varname = get_static_varname(index)
return concat([f'@{varname}', 'D=M'], push_d_onto_stack(), incr_sp())
def push_temp(_, index):
addr = get_temp_addr(index)
return concat([f'@{addr}', 'D=M'], push_d_onto_stack(), incr_sp())
def push_pointer(_, val):
segment = get_pointer_segment(val)
return concat([f'@{segment}', 'D=M'], push_d_onto_stack(), incr_sp())
def push_heap(segment, index):
return concat(load_heap_val_into_d(segment, index), push_d_onto_stack(),
incr_sp())
def push_constant(_, c):
return concat(load_constant_into_d(c), push_d_onto_stack(), incr_sp())