def _unary(compute):
# compute Example: 'M=-D', 'M=!D''
cs.dec_sp()
cs.st_2_dreg()
asm.append_lines(compute)
cs.inc_sp()
return
def _return():
# FLAME=*LCL
asm.set_areg('LCL') # @LCL
asm.set_dreg_from_sgm() # D=M
asm.set_areg('FRAME') # @FRAME
asm.set_sgm_from_dreg() # M=D
# RET=*(FRAME-5)
_set_return()
# *ARG=pop()
cs.dec_sp() # Mem[SP] = Mem[SP] - 1
asm.set_areg_from_sgm() # A=M
asm.set_dreg_from_sgm() # D=M
asm.set_areg('ARG') # @ARG
asm.set_areg_from_sgm() # A=M
asm.set_sgm_from_dreg() # M=D
# SP=ARG+1
asm.set_areg('ARG') # @ARG
asm.set_dreg_from_sgm() # D=M
asm.append_lines('D=D+1') # D=D+1
asm.set_areg('SP') # @SP
asm.set_sgm_from_dreg() # M=D
_set_return_segment('THAT', 1) # THAT=*(FRAME-1)
_set_return_segment('THIS', 2) # THIS=*(FRAME-2)
_set_return_segment('ARG', 3) # ARG=*(FRAME-3)
_set_return_segment('LCL', 4) # LCL=*(FRAME-4)
# GOTO RET.
asm.set_areg('RETURN') # @RETURN
asm.set_areg_from_sgm() # A=M
asm.append_lines('0;JMP')
def _binary(compute):
# compute Example: 'M=M+D', 'M=M-D', 'M=M&D', 'M=M|D'
cs.dec_sp()
cs.st_2_dreg()
cs.dec_sp()
cs.st_2_areg()
asm.append_lines(compute)
cs.inc_sp()
return
def _comp(jump): # TODO use Label!
# jmp Example: 'JEQ', 'JGT', 'JLT'
cs.dec_sp()
cs.st_2_dreg()
cs.dec_sp()
cs.st_2_areg()
asm.append_lines('D=M-D')
#asm.set_areg(str(len(asm.asmLines) + 7)) # 1Line # 7 = 1 + 3 + 1 + 1 + 1
asm.set_areg(str(_count_unlabeld_line() + 7))
asm.append_lines('D;' + jump) # 1Line
_set_bool('FALSE') # 3Lines
#asm.set_areg(str(len(asm.asmLines) + 5)) # 1Line # 5 = 1 + 3 + 1
asm.set_areg(str(_count_unlabeld_line() + 5))
asm.append_lines('0;JMP') # 1Line
_set_bool('TRUE') # 3Lines
cs.inc_sp()
return
def _set_if_goto(label):
cs.dec_sp() # SP--
cs.st_2_dreg() # A=M, D=A
asm.set_areg(label) # A=Label
asm.append_lines('D;JNE') # If D != 0; then goto label.