def gen_condition(self) -> None:
builder = self.builder
line = self.line
# Add loop condition check.
cmp = '<' if self.step > 0 else '>'
comparison = builder.binary_op(builder.read(self.index_target, line),
builder.read(self.end_target, line), cmp, line)
builder.add_bool_branch(comparison, self.body_block, self.loop_exit)
def begin_body(self) -> None:
builder = self.builder
line = self.line
# Read the next list item.
value_box = unsafe_index(builder, builder.read(self.expr_target, line),
builder.read(self.index_target, line), line)
assert value_box
# We coerce to the type of list elements here so that
# iterating with tuple unpacking generates a tuple based
# unpack instead of an iterator based one.
builder.assign(builder.get_assignment_target(self.index),
builder.coerce(value_box, self.target_type, line), line)
def gen_step(self) -> None:
builder = self.builder
line = self.line
# Increment index register. If the range is known to fit in short ints, use
# short ints.
if (is_short_int_rprimitive(self.start_reg.type)
and is_short_int_rprimitive(self.end_reg.type)):
new_val = builder.primitive_op(
unsafe_short_add, [builder.read(self.index_reg, line),
builder.add(LoadInt(self.step))], line)
else:
new_val = builder.binary_op(
builder.read(self.index_reg, line), builder.add(LoadInt(self.step)), '+', line)
builder.assign(self.index_reg, new_val, line)
builder.assign(self.index_target, new_val, line)
def gen_condition(self) -> None:
# We call __next__ on the iterator and check to see if the return value
# is NULL, which signals either the end of the Iterable being traversed
# or an exception being raised. Note that Branch.IS_ERROR checks only
# for NULL (an exception does not necessarily have to be raised).
builder = self.builder
line = self.line
self.next_reg = builder.primitive_op(next_op, [builder.read(self.iter_target, line)], line)
builder.add(Branch(self.next_reg, self.loop_exit, self.body_block, Branch.IS_ERROR))
def gen_step(self) -> None:
# Step to the next item.
builder = self.builder
line = self.line
step = 1 if not self.reverse else -1
builder.assign(self.index_target, builder.primitive_op(
unsafe_short_add,
[builder.read(self.index_target, line),
builder.add(LoadInt(step))], line), line)
def gen_condition(self) -> None:
builder = self.builder
line = self.line
if self.reverse:
# If we are iterating in reverse order, we obviously need
# to check that the index is still positive. Somewhat less
# obviously we still need to check against the length,
# since it could shrink out from under us.
comparison = builder.binary_op(builder.read(self.index_target, line),
builder.add(LoadInt(0)), '>=', line)
second_check = BasicBlock()
builder.add_bool_branch(comparison, second_check, self.loop_exit)
builder.activate_block(second_check)
# For compatibility with python semantics we recalculate the length
# at every iteration.
len_reg = self.load_len()
comparison = builder.binary_op(builder.read(self.index_target, line), len_reg, '<', line)
builder.add_bool_branch(comparison, self.body_block, self.loop_exit)
def gen_step(self) -> None:
builder = self.builder
line = self.line
# We can safely assume that the integer is short, since we are not going to wrap
# around a 63-bit integer.
# NOTE: This would be questionable if short ints could be 32 bits.
new_val = builder.primitive_op(
unsafe_short_add, [builder.read(self.index_reg, line),
builder.add(LoadInt(1))], line)
builder.assign(self.index_reg, new_val, line)
builder.assign(self.index_target, new_val, line)
def init(self, start_reg: Value, end_reg: Value, step: int) -> None:
builder = self.builder
self.start_reg = start_reg
self.end_reg = end_reg
self.step = step
self.end_target = builder.maybe_spill(end_reg)
self.index_reg = builder.maybe_spill_assignable(start_reg)
# Initialize loop index to 0. Assert that the index target is assignable.
self.index_target = builder.get_assignment_target(
self.index) # type: Union[Register, AssignmentTarget]
builder.assign(self.index_target, builder.read(self.index_reg, self.line), self.line)