def prepare_op_call_malloc_nursery_varsize(self, op, fcond):
gc_ll_descr = self.cpu.gc_ll_descr
if not hasattr(gc_ll_descr, 'max_size_of_young_obj'):
raise Exception("unreachable code")
# for boehm, this function should never be called
arraydescr = op.getdescr()
length_box = op.getarg(2)
assert not isinstance(length_box,
Const) # we cannot have a const here!
# can only use spill_or_move_registers_before_call() as a hint if
# we are sure that length_box stays alive and won't be freed now
# (it should always be the case, see below, but better safe than sorry)
if self.rm.stays_alive(length_box):
self.rm.spill_or_move_registers_before_call([r.r0, r.r1])
# the result will be in r0
self.rm.force_allocate_reg(op, selected_reg=r.r0)
# we need r1 as a temporary
tmp_box = TempVar()
self.rm.force_allocate_reg(tmp_box, selected_reg=r.r1)
gcmap = self.get_gcmap([r.r0, r.r1]) # allocate the gcmap *before*
self.rm.possibly_free_var(tmp_box)
# length_box always survives: it's typically also present in the
# next operation that will copy it inside the new array. It's
# fine to load it from the stack too, as long as it's != r0, r1.
lengthloc = self.rm.loc(length_box)
self.rm.possibly_free_var(length_box)
#
itemsize = op.getarg(1).getint()
maxlength = (gc_ll_descr.max_size_of_young_obj - WORD * 2) / itemsize
self.assembler.malloc_cond_varsize(
op.getarg(0).getint(), gc_ll_descr.get_nursery_free_addr(),
gc_ll_descr.get_nursery_top_addr(), lengthloc, itemsize, maxlength,
gcmap, arraydescr)
def ensure_even_odd_pair(self,
origvar,
bindvar,
bind_first=True,
must_exist=True,
load_loc_odd=True,
move_regs=True):
""" Allocates two registers that can be used by the instruction.
origvar: is the original register holding the value
bindvar: is the variable that will be bound
(= self.reg_bindings[bindvar] = new register)
bind_first: the even register will be bound to bindvar,
if bind_first == False: the odd register will
be bound
"""
self._check_type(origvar)
prev_loc = self.loc(origvar, must_exist=must_exist)
var2 = TempVar()
if bindvar is None:
bindvar = TempVar()
if bind_first:
loc, loc2 = self.force_allocate_reg_pair(bindvar, var2,
self.temp_boxes)
else:
loc, loc2 = self.force_allocate_reg_pair(var2, bindvar,
self.temp_boxes)
if isinstance(bindvar, TempVar):
self.temp_boxes.append(bindvar)
self.temp_boxes.append(var2)
assert loc.is_even() and loc2.is_odd()
if move_regs and prev_loc is not loc2:
if load_loc_odd:
self.assembler.regalloc_mov(prev_loc, loc2)
else:
self.assembler.regalloc_mov(prev_loc, loc)
return loc, loc2
def get_scratch_reg(self):
box = TempVar()
reg = self.force_allocate_reg(box, forbidden_vars=self.temp_boxes)
self.temp_boxes.append(box)
return reg
