diff options
| -rw-r--r-- | src/back/generator.py | 174 | ||||
| -rw-r--r-- | src/back/tac.py | 11 |
2 files changed, 182 insertions, 3 deletions
diff --git a/src/back/generator.py b/src/back/generator.py index 851149b..b743684 100644 --- a/src/back/generator.py +++ b/src/back/generator.py @@ -1,5 +1,10 @@ +from back.tac import * +from front.scope import Scope + class Register(object): __shared_state = {} + __current_function = None + __function_registers = {} count = 0 def __init__(self): @@ -7,4 +12,173 @@ class Register(object): def new(self): self.count += 1 + self.__function_registers[self.__current_function].append(self.count) return self.count + + def set_function(self, name): + self.__current_function = name + self.__function_registers[self.__current_function] = [] + + def get_registers(self, name): + return self.__function_registers[name] + +class Generator(object): + def __init__(self): + self.tac_list = TACList() + self.__op_list = [] + + def emit(self, op, tac = None): + if tac: + self.__op_list[self.__op_list.index(tac)] = op + else: + self.__op_list.append(op) + + def generate_prologue(self, name): + Scope().set_function(name) + self.emit(Label(name)) + self.emit("PUSH bp") + self.emit("ADD bp, r0, sp") + for variable in Scope().get_variables()[1]: + self.emit("PUSH r0") + for register in Register().get_registers(name): + self.emit("PUSH r%d" % register) + + def generate_epilogue(self, name): + for variable in Scope().get_variables()[1]: + self.emit("POP r0") + Register().get_registers(name).reverse() + for register in Register().get_registers(name): + self.emit("POP r%d" % register) + Register().get_registers(name).reverse() + self.emit("ADD sp, r0, bp") + self.emit("POP bp") + if name == "main": + self.emit("PUSH rv") + self.emit("PUSH r0") + self.emit("SYS") + else: + self.emit("RET") + + def generate(self): + # pass 1 - generate non-label ops + for tac in self.tac_list: + if isinstance(tac, TAC): + if tac.op == Op.ADD: + self.emit("ADD r%d, r%d, r%d" % (tac.arg1, tac.arg1, tac.arg2)) + elif tac.op == Op.SUB: + self.emit("SUB r%d, r%d, r%d" % (tac.arg1, tac.arg1, tac.arg2)) + elif tac.op == Op.MUL: + self.emit("MUL r%d, r%d, r%d" % (tac.arg1, tac.arg1, tac.arg2)) + elif tac.op == Op.DIV: + self.emit("DIV r%d, r%d, r%d" % (tac.arg1, tac.arg1, tac.arg2)) + elif tac.op == Op.MOD: + self.emit("MOD r%d, r%d, r%d" % (tac.arg1, tac.arg1, tac.arg2)) + elif tac.op == Op.AND: + self.emit("AND r%d, r%d, r%d" % (tac.arg1, tac.arg1, tac.arg2)) + elif tac.op == Op.OR: + self.emit("OR r%d, r%d, r%d" % (tac.arg1, tac.arg1, tac.arg2)) + elif tac.op == Op.NOT: + r = Register().new() + self.emit("MOV r%d, 0" % r) + self.emit("CMP r%d, r%d" % (tac.arg1, r)) + self.emit("EQ r%d" % (tac.arg1)) + elif tac.op == Op.MINUS: + self.emit("SUB r%d, r0, r%d" % (tac.arg1, tac.arg1)) + elif tac.op == Op.STORE: + offset = Scope().get_variable_offset(tac.arg1) + self.emit("SW bp, r%d, %d" % (tac.arg2, offset * 4)) + elif tac.op == Op.LOAD: + offset = Scope().get_variable_offset(tac.arg1) + self.emit("LW bp, r%d, %d" % (tac.arg2, offset * 4)) + elif tac.op == Op.MOV: + self.emit("MOV r%d, %d" % (tac.arg1, tac.arg2)) + elif tac.op == Op.CMP: + self.emit("CMP r%d, r%d" % (tac.arg1, tac.arg2)) + elif tac.op == Op.EQ: + self.emit("EQ r%d" % tac.arg1) + elif tac.op == Op.NE: + self.emit("NE r%d" % tac.arg1) + elif tac.op == Op.LT: + self.emit("LT r%d" % tac.arg1) + elif tac.op == Op.LE: + self.emit("LE r%d" % tac.arg1) + elif tac.op == Op.GE: + self.emit("GE r%d" % tac.arg1) + elif tac.op == Op.GT: + self.emit("GT r%d" % tac.arg1) + elif tac.op == Op.BEZ: + self.emit(tac) + elif tac.op == Op.JMP: + self.emit(tac) + elif tac.op == Op.PUSH: + self.emit("PUSH r%d" % tac.arg1) + elif tac.op == Op.POP: + self.emit("POP r%d" % tac.arg1) + elif tac.op == Op.CALL: + self.emit(tac) + self.emit("ADD r%d, r0, rv" % tac.arg2) + elif tac.op == Op.RETURN: + self.emit("ADD rv, r0, r%d" % tac.arg1) + self.emit(tac) + elif isinstance(tac, FunctionPrologue): + self.generate_prologue(tac.name) + elif isinstance(tac, FunctionEpilogue): + self.generate_epilogue(tac.name) + elif isinstance(tac, Label): + self.emit(Label(tac.name)) + else: + raise Exception("%s is not a valid TACList element", repr(tac)) + + # pass 2 - generate label ops + for op in self.__op_list: + if isinstance(op, TAC): + if op.op == Op.BEZ: + offset = self.get_label_offset(op.arg2, op) + self.emit("BEZ r%d, %d" % (op.arg1, offset), op) + elif op.op == Op.JMP: + offset = self.get_label_offset(op.arg1, op) + self.emit("JMP %d" % offset, op) + elif op.op == Op.CALL: + offset = self.get_label_offset(op.arg1, op) + self.emit("CALL %d" % offset, op) + elif op.op == Op.RETURN: + offset = self.get_label_offset("L%d" % op.arg2, op) + self.emit("JMP %d" % offset, op) + + # pass 3 - remove labels + self.__op_list = filter(lambda x: not isinstance(x, Label), self.__op_list) + + # pass 4 - replace pseudo registers and insert number of registers + def replace_pseudo_regs(op): + regs = Register().count + bp = "r%d" % (regs + 1) + sp = "r%d" % (regs + 2) + rv = "r%d" % (regs + 3) + return op.replace("bp", bp).replace("sp", sp).replace("rv", rv) + + self.__op_list = map(replace_pseudo_regs, self.__op_list) + self.__op_list = [".REGS %d" % Register().count] + self.__op_list + + # print code + #for i in range(len(self.__op_list)): + # print "%04d: %s" % (i, str(self.__op_list[i])) + print "\n".join(self.__op_list) + + def get_label_offset(self, name, tac): + tac_index = 0 + for op in self.__op_list: + if isinstance(op, Label): + continue + if op == tac: + break + tac_index += 1 + + name_index = 0 + for op in self.__op_list: + if isinstance(op, Label): + if op.name == name: + return name_index - tac_index + continue + name_index += 1 + + raise Exception("label %s does not exist" % name) diff --git a/src/back/tac.py b/src/back/tac.py index bff5944..20b14d9 100644 --- a/src/back/tac.py +++ b/src/back/tac.py @@ -37,7 +37,8 @@ Op.GT = Op("GT") # x = !Z && !N Op.BEZ = Op("BEZ") # if x == 0 goto y Op.JMP = Op("JMP") # goto x -Op.PARAM = Op("PARAM") # param x +Op.PUSH = Op("PUSH") # push x +Op.POP = Op("POP") # pop x Op.CALL = Op("CALL") # call x return in y Op.RETURN = Op("RETURN") # return x @@ -59,9 +60,13 @@ class Label(object): def __repr__(self): return "<Label, name: %s>" % self.name -class FunctionLabel(Label): +class FunctionPrologue(Label): def __repr__(self): - return "<FunctionLabel, name: %s>" % self.name + return "<FunctionPrologue, name: %s>" % self.name + +class FunctionEpilogue(Label): + def __repr__(self): + return "<FunctionEpilogue, name: %s>" % self.name class TACList(object): __shared_state = {} |