def _push_from_memory_to_stack(segment, index):
return ('// push from segment {} to stack {} \n'.format(segment, index) +
'@{}\n'.format(index) + 'D=A\n'
'@{}\n'.format(segment) +
'A=M+D\n' + # Pointer arithmetic to index in memory
'D=M\n' + # Assign to D the value of current memory index
push_D_to_stack())
def _push_from_memory_to_stack(segment, index):
return ('// push from segment {} to stack {} \n'.format(segment, index) +
'@{}\n'.format(index) +
'D=A\n'
'@{}\n'.format(segment) +
'A=M+D\n' + # Pointer arithmetic to index in memory
'D=M\n' + # Assign to D the value of current memory index
push_D_to_stack())
def _push_constant_to_stack(val):
"""
Stores value in stack, incrementing by 1 the value of @SP
"""
return ('// push constant {} \n'.format(val) +
'@{}\n'.format(val) +
'D=A\n' +
push_D_to_stack())
def call_handler(function_name, num_args):
global label_counter
continuation_address = 'continuation_{}_{}'.format(function_name,
label_counter)
label_counter += 1
return ('// call fn {} with locals {}\n'.format(function_name, num_args) +
'@{}\n'.format(continuation_address) +
'D=A\n' +
push_D_to_stack() + # Store return address (caller) in stack
'@LCL\n' +
'D=M\n' +
push_D_to_stack() + # Store LCL address (caller) in stack
'@ARG\n' +
'D=M\n' +
push_D_to_stack() + # Store ARG address (caller) in stack
'@THIS\n' +
'D=M\n' +
push_D_to_stack() + # Store THIS address (caller) in stack
'@THAT\n' +
'D=M\n' +
push_D_to_stack() + # Store THAT address (caller) in stack
'@SP\n' +
'D=M\n' +
'@5\n' +
'D=D-A\n' +
'@{}\n'.format(num_args) +
'D=D-A\n' +
'@ARG\n' + # NOQA Set current ARG address to stack head -5 (state of caller) - num_args (prev pushed to stack)
'M=D\n' +
'@SP\n' +
'D=M\n' +
'@LCL\n' +
'M=D\n' + # Set current LCL address to stack head
goto_handler(function_name) +
label_handler(continuation_address)
)
def _push_from_static_to_stack(index, file):
return ('// push from static {} to stack \n'.format(index) +
'@{}_{}\n'.format(file, index) + 'D=M\n' + push_D_to_stack())
def _push_from_register_to_stack(register):
return ('@{}\n'.format(register) + 'D=M\n' + push_D_to_stack())
def _push_constant_to_stack(val):
"""
Stores value in stack, incrementing by 1 the value of @SP
"""
return ('// push constant {} \n'.format(val) + '@{}\n'.format(val) +
'D=A\n' + push_D_to_stack())
def _push_from_static_to_stack(index, file):
return ('// push from static {} to stack \n'.format(index) +
'@{}_{}\n'.format(file, index) +
'D=M\n' +
push_D_to_stack())
def _push_from_register_to_stack(register):
return ('@{}\n'.format(register) +
'D=M\n' +
push_D_to_stack())