def __init__(self):
self.dotdata = []
self.main_procedure = mips.MIPSProcedureNode("main")
self.current_procedure = self.main_procedure
self.dottext = [self.main_procedure]
self.main_size = None
def generate_abort(self):
#falta imprimir el mensaje
self.current_procedure = mips.MIPSProcedureNode(ABORT)
self.register_comment("Printing message")
self.register_instruction(mips.MIPSLoadInmediateNode, v0,
SYSCALL_PRINT_STR)
self.register_instruction(mips.MIPSSyscallNode)
self.register_empty()
self.register_comment("Aborting execution")
self.register_instruction(mips.MIPSLoadInmediateNode, v0, SYSCALL_EXIT)
self.register_instruction(mips.MIPSSyscallNode)
self.register_empty()
self.dottext.append(self.current_procedure)
def visit(self, node: cil.CILFunctionNode):
self.current_procedure = mips.MIPSProcedureNode(
node.method_info.method_name)
self.register_comment("Pushing $ra")
self.register_push(ra)
self.register_empty()
self.register_comment("Saving $fp")
self.register_instruction(mips.MIPSMoveNode, fp, sp)
self.register_empty()
self.register_comment("Reserving space for locals")
self.register_instruction(mips.MIPSAddInmediateNode, sp, sp,
-4 * len(node.localvars))
self.register_empty()
self.generate_args_offsets(node.arguments)
self.generate_locals_offsets(node.localvars)
self.register_comment("Executing instructions")
for inst in node.instructions:
self.visit(inst)
self.register_empty()
self.register_comment("Restoring saved $ra")
self.register_instruction(mips.MIPSLoadWordNode, ra, RA_OFFSET,
fp) #stored $ra
self.register_empty()
self.register_comment("Restoring saved $fp")
self.register_instruction(mips.MIPSLoadWordNode, fp, OLD_FP_OFFSET,
fp) #stored (old)$fp
self.register_empty()
AR = 4 * (len(node.localvars) + len(node.arguments) + 2)
self.register_comment("Cleaning stack after call")
self.register_instruction(mips.MIPSAddInmediateNode, sp, sp, AR)
self.register_empty()
self.register_comment("Return jump")
self.register_instruction(mips.MIPSJumpRegisterNode, ra)
self.register_empty()
self.dottext.append(self.current_procedure)
def generate_strcmp_code(self):
self.current_procedure = mips.MIPSProcedureNode(STR_CMP)
#comparing lengths
self.register_instruction(mips.MIPSCommentNode, "Comparing lengths")
self.register_instruction(mips.MIPSLoadWordNode, s0,
LENGTH_ATTR_OFFSET, t0) #length offset
self.register_instruction(mips.MIPSLoadWordNode, s1,
LENGTH_ATTR_OFFSET, t1)
self.register_instruction(mips.MIPSBranchOnNotEqualNode, s0, s1,
"strcmp_neq")
self.register_instruction(mips.MIPSEmptyInstruction)
#comparing char by char
self.register_instruction(mips.MIPSCommentNode,
"Comparing char by char")
self.register_instruction(mips.MIPSLoadWordNode, s0, CHARS_ATTR_OFFSET,
t0) #char array pointer offset
self.register_instruction(mips.MIPSLoadWordNode, s1, CHARS_ATTR_OFFSET,
t1)
self.register_instruction(mips.MIPSEmptyInstruction)
#char by char loop
self.register_instruction(mips.MIPSLabelNode, "strcmp_loop")
self.register_instruction(mips.MIPSLoadByteNode, s2, 0, s0)
self.register_instruction(mips.MIPSLoadByteNode, s3, 0, s1)
self.register_instruction(mips.MIPSBranchOnNotEqualNode, s2, s3,
"strcmp_neq")
self.register_instruction(mips.MIPSBranchOnEqualNode, s2, zero,
"strcmp_eq")
self.register_instruction(mips.MIPSJumpNode, "strcmp_loop")
self.register_instruction(mips.MIPSEmptyInstruction)
self.register_instruction(mips.MIPSLabelNode, "strcmp_eq")
self.register_instruction(mips.MIPSLoadInmediateNode, a0, 1)
self.register_instruction(mips.MIPSJumpRegisterNode, ra)
self.register_instruction(mips.MIPSEmptyInstruction)
self.register_instruction(mips.MIPSLabelNode, "strcmp_neq")
self.register_instruction(mips.MIPSLoadInmediateNode, a0, 0)
self.register_instruction(mips.MIPSJumpRegisterNode, ra)
self.register_instruction(mips.MIPSEmptyInstruction)
self.dottext.append(self.current_procedure)
def generate_copy(self):
#copies from t1 to t0 a0 bytes
self.current_procedure = mips.MIPSProcedureNode(COPY)
self.register_instruction(mips.MIPSLabelNode, "copy_loop")
self.register_instruction(mips.MIPSBranchOnEqualNode, zero, a0,
"copy_end")
self.register_instruction(mips.MIPSLoadByteNode, t7, 0, t1)
self.register_instruction(mips.MIPSStoreByteNode, t7, 0, t0)
self.register_instruction(mips.MIPSAddInmediateNode, t0, t0, 1)
self.register_instruction(mips.MIPSAddInmediateNode, t1, t1, 1)
self.register_instruction(mips.MIPSAddInmediateNode, a0, a0, -1)
self.register_instruction(mips.MIPSJumpNode, "copy_loop")
self.register_empty()
self.register_instruction(mips.MIPSLabelNode, "copy_end")
self.register_instruction(mips.MIPSJumpRegisterNode, ra)
self.register_empty()
self.dottext.append(self.current_procedure)
def generate_str_length(self):
#calculates the length of the null-terminated char array referenced by $a0 and stores it in $a0
self.current_procedure = mips.MIPSProcedureNode(LENGTH)
self.register_instruction(mips.MIPSLoadInmediateNode, t6, 0)
self.register_empty()
self.register_instruction(mips.MIPSLabelNode, "length_loop")
self.register_instruction(mips.MIPSLoadByteNode, t7, 0, a0)
self.register_instruction(mips.MIPSBranchOnEqualNode, zero, t7,
"length_end")
self.register_instruction(mips.MIPSAddNode, t6, t6, 1)
self.register_instruction(mips.MIPSAddNode, a0, a0, 1)
self.register_instruction(mips.MIPSJumpNode, "length_loop")
self.register_empty()
self.register_instruction(mips.MIPSLabelNode, "length_end")
self.register_instruction(mips.MIPSMoveNode, a0, t6)
self.register_instruction(mips.MIPSJumpRegisterNode, ra)
self.register_empty()
self.dottext.append(self.current_procedure)
def generate_exit_program(self):
self.current_procedure = mips.MIPSProcedureNode(EXIT)
#que vamos a hacer
self.dottext.append(self.current_procedure)