def stack_virtualise_expr (expr, sp_offs):
if expr.is_op ('MemAcc') and is_stack (expr.vals[0]):
[m, p] = expr.vals
if expr.typ == syntax.word8T:
ps = [(syntax.mk_minus (p, syntax.mk_word32 (n)), n)
for n in [0, 1, 2, 3]]
elif expr.typ == syntax.word32T:
ps = [(p, 0)]
else:
assert expr.typ == syntax.word32T, expr
ptrs = [(p, 'MemAcc') for (p, _) in ps]
if sp_offs == None:
return (ptrs, None)
# FIXME: very 32-bit specific
ps = [(p, n) for (p, n) in ps if p in sp_offs
if sp_offs[p][1] % 4 == 0]
if not ps:
return (ptrs, expr)
[(p, n)] = ps
(k, offs) = sp_offs[p]
v = mk_var (('Fake', k, offs), syntax.word32T)
if n != 0:
v = syntax.mk_shiftr (v, n * 8)
v = syntax.mk_cast (v, expr.typ)
return (ptrs, v)
elif expr.kind == 'Op':
vs = [stack_virtualise_expr (v, sp_offs) for v in expr.vals]
return ([p for (ptrs, _) in vs for p in ptrs],
syntax.Expr ('Op', expr.typ, name = expr.name,
vals = [v for (_, v) in vs]))
else:
return ([], expr)
def stack_virtualise_expr(expr, sp_offs):
if expr.is_op('MemAcc') and is_stack(expr.vals[0]):
[m, p] = expr.vals
if expr.typ == syntax.word8T:
ps = [(syntax.mk_minus(p, syntax.mk_word32(n)), n)
for n in [0, 1, 2, 3]]
elif expr.typ == syntax.word32T:
ps = [(p, 0)]
else:
assert expr.typ == syntax.word32T, expr
ptrs = [(p, 'MemAcc') for (p, _) in ps]
if sp_offs == None:
return (ptrs, None)
# FIXME: very 32-bit specific
ps = [(p, n) for (p, n) in ps if p in sp_offs
if sp_offs[p][1] % 4 == 0]
if not ps:
return (ptrs, expr)
[(p, n)] = ps
if p not in sp_offs:
raise StackOffsMissing()
(k, offs) = sp_offs[p]
v = mk_var(('Fake', k, offs), syntax.word32T)
if n != 0:
v = syntax.mk_shiftr(v, n * 8)
v = syntax.mk_cast(v, expr.typ)
return (ptrs, v)
elif expr.kind == 'Op':
vs = [stack_virtualise_expr(v, sp_offs) for v in expr.vals]
return ([p for (ptrs, _) in vs for p in ptrs],
syntax.adjust_op_vals(expr, [v for (_, v) in vs]))
else:
return ([], expr)
def v_eqs_to_split (p, pair, v_eqs, restrs, hyps, tags = None):
trace ('v_eqs_to_split: (%s, %s)' % pair)
((l_n, l_init, l_step), (r_n, r_init, r_step)) = pair
l_details = (l_n, (l_init, l_step), mk_seq_eqs (p, l_n, l_step, True)
+ [v_i[0] for (v_i, v_j) in v_eqs if v_j == 'Const'])
r_details = (r_n, (r_init, r_step), mk_seq_eqs (p, r_n, r_step, False)
+ c_memory_loop_invariant (p, r_n, l_n))
eqs = [(v_i[0], mk_cast (v_j[0], v_i[0].typ))
for (v_i, v_j) in v_eqs if v_j != 'Const']
n = 2
split = (l_details, r_details, eqs, n, (n * r_step) - 1)
trace ('Split: %s' % (split, ))
if tags == None:
tags = p.pairing.tags
hyps = hyps + check.split_loop_hyps (tags, split, restrs, exit = True)
r_max = find_split_limit (p, r_n, restrs, hyps, 'Offset',
bound = (n + 2) * r_step, must_find = False,
hints = [n * r_step, n * r_step + 1])
if r_max == None:
trace ('v_eqs_to_split: no RHS limit')
return None
if r_max > n * r_step:
trace ('v_eqs_to_split: RHS limit not %d' % (n * r_step))
return None
trace ('v_eqs_to_split: split %s' % (split,))
return split
