def _set(self, dst, src):
"""
Special cases:
* if dst is an ExprSlice, expand it to affect the full Expression
* if dst already known, sources are merged
"""
if dst.size != src.size:
raise RuntimeError("sanitycheck: args must have same size! %s" %
([(str(arg), arg.size) for arg in [dst, src]]))
if isinstance(dst, m2_expr.ExprSlice):
# Complete the source with missing slice parts
new_dst = dst.arg
rest = [(m2_expr.ExprSlice(dst.arg, r[0], r[1]), r[0], r[1])
for r in dst.slice_rest()]
all_a = [(src, dst.start, dst.stop)] + rest
all_a.sort(key=lambda x: x[1])
args = [expr for (expr, _, _) in all_a]
new_src = m2_expr.ExprCompose(*args)
else:
new_dst, new_src = dst, src
if new_dst in self._assigns and isinstance(new_src,
m2_expr.ExprCompose):
if not isinstance(self[new_dst], m2_expr.ExprCompose):
# prev_RAX = 0x1122334455667788
# input_RAX[0:8] = 0x89
# final_RAX -> ? (assignment are in parallel)
raise RuntimeError("Concurent access on same bit not allowed")
# Consider slice grouping
expr_list = [(new_dst, new_src), (new_dst, self[new_dst])]
# Find collision
e_colision = reduce(lambda x, y: x.union(y),
(self.get_modified_slice(dst, src)
for (dst, src) in expr_list), set())
# Sort interval collision
known_intervals = sorted([(x[1], x[2]) for x in e_colision])
for i, (_, stop) in enumerate(known_intervals[:-1]):
if stop > known_intervals[i + 1][0]:
raise RuntimeError(
"Concurent access on same bit not allowed")
# Fill with missing data
missing_i = get_missing_interval(known_intervals, 0, new_dst.size)
remaining = ((m2_expr.ExprSlice(new_dst, *interval), interval[0],
interval[1]) for interval in missing_i)
# Build the merging expression
args = list(e_colision.union(remaining))
args.sort(key=lambda x: x[1])
starts = [start for (_, start, _) in args]
assert len(set(starts)) == len(starts)
args = [expr for (expr, _, _) in args]
new_src = m2_expr.ExprCompose(*args)
self._assigns[new_dst] = new_src
def __setitem__(self, dst, src):
"""
Special cases:
* if dst is an ExprSlice, expand it to affect the full Expression
* if dst already known, sources are merged
"""
if dst.size != src.size:
raise RuntimeError(
"sanitycheck: args must have same size! %s" %
([(str(arg), arg.size) for arg in [dst, src]]))
if isinstance(dst, m2_expr.ExprSlice):
# Complete the source with missing slice parts
new_dst = dst.arg
rest = [(m2_expr.ExprSlice(dst.arg, r[0], r[1]), r[0], r[1])
for r in dst.slice_rest()]
all_a = [(src, dst.start, dst.stop)] + rest
all_a.sort(key=lambda x: x[1])
new_src = m2_expr.ExprCompose(all_a)
else:
new_dst, new_src = dst, src
if new_dst in self and isinstance(new_src, m2_expr.ExprCompose):
if not isinstance(self[new_dst], m2_expr.ExprCompose):
# prev_RAX = 0x1122334455667788
# input_RAX[0:8] = 0x89
# final_RAX -> ? (assignment are in parallel)
raise RuntimeError("Concurent access on same bit not allowed")
# Consider slice grouping
expr_list = [(new_dst, new_src),
(new_dst, self[new_dst])]
# Find collision
e_colision = reduce(lambda x, y: x.union(y),
(self.get_modified_slice(dst, src)
for (dst, src) in expr_list),
set())
# Sort interval collision
known_intervals = sorted([(x[1], x[2]) for x in e_colision])
for i, (_, stop) in enumerate(known_intervals[:-1]):
if stop > known_intervals[i + 1][0]:
raise RuntimeError(
"Concurent access on same bit not allowed")
# Fill with missing data
missing_i = get_missing_interval(known_intervals, 0, new_dst.size)
remaining = ((m2_expr.ExprSlice(new_dst, *interval),
interval[0],
interval[1])
for interval in missing_i)
# Build the merging expression
new_src = m2_expr.ExprCompose(e_colision.union(remaining))
super(AssignBlock, self).__setitem__(new_dst, new_src)
def merge_multi_affect(self, affect_list):
"""
If multiple affection to a same ExprId are present in @affect_list,
merge them (in place).
For instance, XCGH AH, AL semantic is
[
RAX = {RAX[0:8],0,8, RAX[0:8],8,16, RAX[16:64],16,64}
RAX = {RAX[8:16],0,8, RAX[8:64],8,64}
]
This function will update @affect_list to replace previous ExprAff by
[
RAX = {RAX[8:16],0,8, RAX[0:8],8,16, RAX[16:64],16,64}
]
"""
# Extract side effect
effect = {}
for expr in affect_list:
effect[expr.dst] = effect.get(expr.dst, []) + [expr]
# Find candidates
for dst, expr_list in effect.items():
if len(expr_list) <= 1:
continue
# Only treat ExprCompose list
if any(map(lambda e: not(isinstance(e.src, m2_expr.ExprCompose)),
expr_list)):
continue
# Find collision
e_colision = reduce(lambda x, y: x.union(y),
(e.get_modified_slice() for e in expr_list),
set())
# Sort interval collision
known_intervals = sorted([(x[1], x[2]) for x in e_colision])
# Fill with missing data
missing_i = get_missing_interval(known_intervals, 0, dst.size)
remaining = ((m2_expr.ExprSlice(dst, *interval),
interval[0],
interval[1])
for interval in missing_i)
# Build the merging expression
slices = sorted(e_colision.union(remaining), key=lambda x: x[1])
final_dst = m2_expr.ExprCompose(slices)
# Remove unused expression
for expr in expr_list:
affect_list.remove(expr)
# Add the merged one
affect_list.append(m2_expr.ExprAff(dst, final_dst))
def merge_multi_affect(self, affect_list):
"""
If multiple affection to a same ExprId are present in @affect_list,
merge them (in place).
For instance, XCGH AH, AL semantic is
[
RAX = {RAX[0:8],0,8, RAX[0:8],8,16, RAX[16:64],16,64}
RAX = {RAX[8:16],0,8, RAX[8:64],8,64}
]
This function will update @affect_list to replace previous ExprAff by
[
RAX = {RAX[8:16],0,8, RAX[0:8],8,16, RAX[16:64],16,64}
]
"""
# Extract side effect
effect = {}
for expr in affect_list:
effect[expr.dst] = effect.get(expr.dst, []) + [expr]
# Find candidates
for dst, expr_list in effect.items():
if len(expr_list) <= 1:
continue
# Only treat ExprCompose list
if any(map(lambda e: not(isinstance(e.src, m2_expr.ExprCompose)),
expr_list)):
continue
# Find collision
e_colision = reduce(lambda x, y: x.union(y),
(e.get_modified_slice() for e in expr_list),
set())
# Sort interval collision
known_intervals = sorted([(x[1], x[2]) for x in e_colision])
# Fill with missing data
missing_i = get_missing_interval(known_intervals, 0, dst.size)
remaining = ((m2_expr.ExprSlice(dst, *interval),
interval[0],
interval[1])
for interval in missing_i)
# Build the merging expression
slices = sorted(e_colision.union(remaining), key=lambda x: x[1])
final_dst = m2_expr.ExprCompose(slices)
# Remove unused expression
for expr in expr_list:
affect_list.remove(expr)
# Add the merged one
affect_list.append(m2_expr.ExprAff(dst, final_dst))