def reorder(dvars, fol):
"""Shift integers up in the variable order of `fol.bdd`."""
assert dvars, dvars
bdd = fol.bdd
for var, d in dvars.items():
level = d['level']
dv = fol.vars[var]
var_type = dv['type']
if var_type == 'bool':
bitnames = [var]
else:
assert var_type in TYPE_HINTS, var_type
bitnames = dv['bitnames']
# print('Shifting bits {bitnames} to '
# 'level {level}'.format(
# level=level,
# bitnames=bitnames))
# assert each bit goes up in level
for bit in bitnames:
old_level = bdd.level_of_var(bit)
assert old_level >= level, (old_level, level)
# shift to levels wanted
order = [bdd.var_at_level(i) for i in range(len(bdd.vars))]
below = order[:level]
above = order[level:]
above = [v for v in above if v not in bitnames]
new_order = below + bitnames + above
dorder = {var: i for i, var in enumerate(new_order)}
_bdd.reorder(bdd, dorder)
order = [bdd.var_at_level(i) for i in range(len(bdd.vars))]
assert order == new_order, (order, new_order)
def reorder(dvars, fol):
"""Shift integers up in the variable order of `fol.bdd`."""
assert dvars, dvars
bdd = fol.bdd
for var, d in dvars.items():
level = d['level']
dv = fol.vars[var]
var_type = dv['type']
if var_type == 'bool':
bitnames = [var]
else:
assert var_type in TYPE_HINTS, var_type
bitnames = dv['bitnames']
# print('Shifting bits {bitnames} to '
# 'level {level}'.format(
# level=level,
# bitnames=bitnames))
# assert each bit goes up in level
for bit in bitnames:
old_level = bdd.level_of_var(bit)
assert old_level >= level, (old_level, level)
# shift to levels wanted
order = [bdd.var_at_level(i)
for i in range(len(bdd.vars))]
below = order[:level]
above = order[level:]
above = [v for v in above if v not in bitnames]
new_order = below + bitnames + above
dorder = {var: i for i, var in enumerate(new_order)}
_bdd.reorder(bdd, dorder)
order = [bdd.var_at_level(i)
for i in range(len(bdd.vars))]
assert order == new_order, (order, new_order)
def test_count_nodes():
bdd = cudd.BDD()
[bdd.add_var(var) for var in ['x', 'y', 'z']]
u = bdd.add_expr('x /\ y')
v = bdd.add_expr('x /\ z')
assert len(u) == 3, len(u)
assert len(v) == 3, len(v)
cudd.reorder(bdd, dict(x=0, y=1, z=2))
n = cudd.count_nodes([u, v])
assert n == 5, n
cudd.reorder(bdd, dict(z=0, y=1, x=2))
n = cudd.count_nodes([u, v])
assert n == 4, n
def test_count_nodes():
bdd = cudd.BDD()
[bdd.add_var(var) for var in ['x', 'y', 'z']]
u = bdd.add_expr('x /\ y')
v = bdd.add_expr('x /\ z')
assert len(u) == 3, len(u)
assert len(v) == 3, len(v)
cudd.reorder(bdd, dict(x=0, y=1, z=2))
n = cudd.count_nodes([u, v])
assert n == 5, n
cudd.reorder(bdd, dict(z=0, y=1, x=2))
n = cudd.count_nodes([u, v])
assert n == 4, n
def test_reorder():
bdd = cudd.BDD()
dvars = ['x', 'y', 'z']
for var in dvars:
bdd.add_var(var)
for i, var in enumerate(dvars):
level = bdd.level_of_var(var)
assert level == i, (var, level, i)
order = dict(y=0, z=1, x=2)
cudd.reorder(bdd, order)
for var, level_ in order.iteritems():
level = bdd.level_of_var(var)
assert level == level_, (var, level, level_)
def test_reorder():
bdd = cudd.BDD()
dvars = ['x', 'y', 'z']
for var in dvars:
bdd.add_var(var)
for i, var in enumerate(dvars):
level = bdd.level_of_var(var)
assert level == i, (var, level, i)
order = dict(y=0, z=1, x=2)
cudd.reorder(bdd, order)
for var in order:
level_ = order[var]
level = bdd.level_of_var(var)
assert level == level_, (var, level, level_)
def test_copy_bdd_different_order():
bdd = cudd.BDD()
other = cudd.BDD()
assert bdd != other
dvars = ['x', 'y', 'z', 'w']
for index, var in enumerate(dvars):
bdd.add_var(var, index=index)
other.add_var(var, index=index)
# reorder
order = dict(w=0, x=1, y=2, z=3)
cudd.reorder(other, order)
# confirm resultant order
for var in order:
level_ = order[var]
level = other.level_of_var(var)
assert level == level_, (var, level, level_)
# same indices
for var in dvars:
i = bdd._index_of_var[var]
j = other._index_of_var[var]
assert i == j, (i, j)
# but different levels
for var in dvars:
i = bdd.level_of_var(var)
j = other.level_of_var(var)
assert i != j, (i, j)
# copy
s = '(x | !y) & w & (z | !w)'
u0 = bdd.add_expr(s)
u1 = cudd.copy_bdd(u0, bdd, other)
u2 = cudd.copy_bdd(u1, other, bdd)
assert u0 == u2, (u0, u2)
u3 = cudd.copy_bdd(other.false, other, bdd)
assert u3 != u2, (u3, u2)
# verify
w = other.add_expr(s)
assert w == u1, (w, u1)
del u0, u1, u2, u3, w
def test_copy_bdd_different_order():
bdd = cudd.BDD()
other = cudd.BDD()
assert bdd != other
dvars = ['x', 'y', 'z', 'w']
for index, var in enumerate(dvars):
bdd.add_var(var, index=index)
other.add_var(var, index=index)
# reorder
order = dict(w=0, x=1, y=2, z=3)
cudd.reorder(other, order)
# confirm resultant order
for var in order:
level_ = order[var]
level = other.level_of_var(var)
assert level == level_, (var, level, level_)
# same indices
for var in dvars:
i = bdd._index_of_var[var]
j = other._index_of_var[var]
assert i == j, (i, j)
# but different levels
for var in dvars:
i = bdd.level_of_var(var)
j = other.level_of_var(var)
assert i != j, (i, j)
# copy
s = '(x \/ ~ y) /\ w /\ (z \/ ~ w)'
u0 = bdd.add_expr(s)
u1 = cudd.copy_bdd(u0, other)
u2 = cudd.copy_bdd(u1, bdd)
assert u0 == u2, (u0, u2)
u3 = cudd.copy_bdd(other.false, bdd)
assert u3 != u2, (u3, u2)
# verify
w = other.add_expr(s)
assert w == u1, (w, u1)
"""How to configure reordering in CUDD via `dd.cudd`."""
import pprint
from dd import cudd
bdd = cudd.BDD()
vrs = ['x', 'y', 'z']
bdd.declare(*vrs)
# get the variable order
levels = {var: bdd.level_of_var(var) for var in vrs}
print(levels)
# change the levels
desired_levels = dict(x=2, y=0, z=1)
cudd.reorder(bdd, desired_levels)
# confirm that variables are now where desired
new_levels = {var: bdd.level_of_var(var) for var in vrs}
print(new_levels)
# dynamic reordering is initially turned on
config = bdd.configure()
pprint.pprint(config)
# turn off dynamic reordering
bdd.configure(reordering=False)
# confirm dynamic reordering is now off
config = bdd.configure()
pprint.pprint(config)