def preprocess_binop(self, expr):
"""
Several nml operators are not directly support by nfo so we have to work
around that by implementing those operators in terms of others.
@return: A pre-processed version of the expression.
@rtype: L{Expression}
"""
assert isinstance(expr, expression.BinOp)
if expr.op == nmlop.CMP_LT:
# return value is 0, 1 or 2, we want to map 0 to 1 and the others to 0
expr = nmlop.VACT2_CMP(expr.expr1, expr.expr2)
# reduce the problem to 0/1
expr = nmlop.MIN(expr, 1)
# and invert the result
expr = nmlop.XOR(expr, 1)
elif expr.op == nmlop.CMP_GT:
# return value is 0, 1 or 2, we want to map 2 to 1 and the others to 0
expr = nmlop.VACT2_CMP(expr.expr1, expr.expr2)
# subtract one
expr = nmlop.SUB(expr, 1)
# map -1 and 0 to 0
expr = nmlop.MAX(expr, 0)
elif expr.op == nmlop.CMP_LE:
# return value is 0, 1 or 2, we want to map 2 to 0 and the others to 1
expr = nmlop.VACT2_CMP(expr.expr1, expr.expr2)
# swap 0 and 2
expr = nmlop.XOR(expr, 2)
# map 1/2 to 1
expr = nmlop.MIN(expr, 1)
elif expr.op == nmlop.CMP_GE:
# return value is 0, 1 or 2, we want to map 1/2 to 1
expr = nmlop.VACT2_CMP(expr.expr1, expr.expr2)
expr = nmlop.MIN(expr, 1)
elif expr.op == nmlop.CMP_EQ:
# return value is 0, 1 or 2, we want to map 1 to 1, other to 0
expr = nmlop.VACT2_CMP(expr.expr1, expr.expr2)
expr = nmlop.AND(expr, 1)
elif expr.op == nmlop.CMP_NEQ:
# same as CMP_EQ but invert the result
expr = nmlop.VACT2_CMP(expr.expr1, expr.expr2)
expr = nmlop.AND(expr, 1)
expr = nmlop.XOR(expr, 1)
elif expr.op == nmlop.HASBIT:
# hasbit(x, n) ==> (x >> n) & 1
expr = nmlop.SHIFTU_RIGHT(expr.expr1, expr.expr2)
expr = nmlop.AND(expr, 1)
elif expr.op == nmlop.NOTHASBIT:
# !hasbit(x, n) ==> ((x >> n) & 1) ^ 1
expr = nmlop.SHIFTU_RIGHT(expr.expr1, expr.expr2)
expr = nmlop.AND(expr, 1)
expr = nmlop.XOR(expr, 1)
return expr.reduce()
def parse(self, expr):
# Preprocess the expression
if isinstance(expr, expression.SpecialParameter):
# do this first, since it may evaluate to a BinOp
expr = expr.to_reading()
if isinstance(expr, expression.BinOp):
expr = self.preprocess_binop(expr)
elif isinstance(expr, expression.Boolean):
expr = nmlop.MINU(expr.expr, 1)
elif isinstance(expr, expression.BinNot):
expr = nmlop.XOR(expr.expr, 0xFFFFFFFF)
elif isinstance(
expr,
expression.TernaryOp) and not expr.supported_by_actionD(False):
expr = self.preprocess_ternaryop(expr)
elif isinstance(expr, expression.StorageOp):
expr = self.preprocess_storageop(expr)
# Try to parse the expression to a list of variables+operators
if isinstance(expr, expression.ConstantNumeric):
self.parse_constant(expr)
elif isinstance(expr, expression.Parameter) and isinstance(
expr.num, expression.ConstantNumeric):
self.parse_param(expr)
elif isinstance(expr, expression.Variable):
self.parse_variable(expr)
elif expr.supported_by_actionD(False):
self.parse_via_actionD(expr)
elif isinstance(expr, expression.BinOp):
self.parse_binop(expr)
elif isinstance(expr, expression.Not):
self.parse_not(expr)
elif isinstance(expr, expression.String):
self.parse_string(expr)
elif isinstance(expr,
(VarAction2LoadTempVar, VarAction2LoadCallParam)):
self.var_list.append(expr)
self.var_list_size += expr.get_size()
elif isinstance(expr, expression.SpriteGroupRef):
self.parse_proc_call(expr)
else:
expr.supported_by_action2(True)
raise AssertionError(
"supported_by_action2 should have raised the correct error already"
)
def builtin_getbits(name, args, pos):
"""
getbits(value, first, amount) builtin function.
@return Extract C{amount} bits starting at C{first} from C{value},
that is (C{value} >> C{first}) & (1 << C{amount} - 1)
"""
if len(args) != 3:
raise generic.ScriptError(name + "() must have exactly three parameters", pos)
# getbits(value, first, amount) = (value >> first) & ((0xFFFFFFFF << amount) ^ 0xFFFFFFFF)
part1 = nmlop.SHIFTU_RIGHT(args[0], args[1], pos)
part2 = nmlop.SHIFT_LEFT(0xFFFFFFFF, args[2], pos)
part3 = nmlop.XOR(part2, 0xFFFFFFFF, pos)
return nmlop.AND(part1, part3, pos)
def parse_not(self, expr):
self.parse_binop(nmlop.XOR(expr.expr, 1))
def value_sign_extend(var, info):
#r = (x ^ m) - m; with m being (1 << (num_bits -1))
m = expression.ConstantNumeric(1 << (info['size'] - 1))
return nmlop.SUB(nmlop.XOR(var, m), m)
