def test_frozen_user_class2(self):
class C:
def __add__(self, other):
return 4
def _freeze_(self):
return True
c = C()
d = C()
def f():
return c + d
graph = self.codetest(f)
results = []
def visit(link):
if isinstance(link, Link):
if link.target == graph.returnblock:
results.extend(link.args)
traverse(visit, graph)
assert results == [Constant(4)]
def remove_assertion_errors(graph):
"""Remove branches that go directly to raising an AssertionError,
assuming that AssertionError shouldn't occur at run-time. Note that
this is how implicit exceptions are removed (see _implicit_ in
flowcontext.py).
"""
if simplify_disabled(graph): return
def visit(block):
if isinstance(block, Block):
for i in range(len(block.exits) - 1, -1, -1):
exit = block.exits[i]
if not (exit.target is graph.exceptblock
and exit.args[0] == Constant(AssertionError)):
continue
# can we remove this exit without breaking the graph?
if len(block.exits) < 2:
break
if block.exitswitch == c_last_exception:
if exit.exitcase is None:
break
if len(block.exits) == 2:
# removing the last non-exceptional exit
block.exitswitch = None
exit.exitcase = None
# remove this exit
lst = list(block.exits)
del lst[i]
block.recloseblock(*lst)
traverse(visit, graph)
def remove_assertion_errors(graph):
"""Remove branches that go directly to raising an AssertionError,
assuming that AssertionError shouldn't occur at run-time. Note that
this is how implicit exceptions are removed (see _implicit_ in
flowcontext.py).
"""
def visit(block):
if isinstance(block, Block):
for i in range(len(block.exits)-1, -1, -1):
exit = block.exits[i]
if not (exit.target is graph.exceptblock and
exit.args[0] == Constant(AssertionError)):
continue
# can we remove this exit without breaking the graph?
if len(block.exits) < 2:
break
if block.exitswitch == c_last_exception:
if exit.exitcase is None:
break
if len(block.exits) == 2:
# removing the last non-exceptional exit
block.exitswitch = None
exit.exitcase = None
# remove this exit
lst = list(block.exits)
del lst[i]
block.recloseblock(*lst)
traverse(visit, graph)
def test_frozen_user_class2(self):
class C:
def __add__(self, other):
return 4
def _freeze_(self):
return True
c = C()
d = C()
def f():
return c + d
graph = self.codetest(f)
results = []
def visit(link):
if isinstance(link, Link):
if link.target == graph.returnblock:
results.extend(link.args)
traverse(visit, graph)
assert results == [Constant(4)]
def test_jump_target_specialization(self):
x = self.codetest(self.jump_target_specialization)
def visitor(node):
if isinstance(node, Block):
for op in node.operations:
assert op.opname != 'mul', "mul should have disappeared"
traverse(visitor, x)
def test_frozen_user_class1(self):
class C:
def __nonzero__(self):
return True
def _freeze_(self):
return True
c = C()
def f():
if c:
return 1
else:
return 2
graph = self.codetest(f)
results = []
def visit(link):
if isinstance(link, Link):
if link.target == graph.returnblock:
results.extend(link.args)
traverse(visit, graph)
assert len(results) == 1
def eliminate_empty_blocks(graph):
"""Eliminate basic blocks that do not contain any operations.
When this happens, we need to replace the preceeding link with the
following link. Arguments of the links should be updated."""
if simplify_disabled(graph): return
def visit(link):
if isinstance(link, Link):
while not link.target.operations:
block1 = link.target
if block1.exitswitch is not None:
break
if not block1.exits:
break
exit = block1.exits[0]
assert block1 is not exit.target, (
"the graph contains an empty infinite loop")
outputargs = []
for v in exit.args:
if isinstance(v, Variable):
# this variable is valid in the context of block1
# but it must come from 'link'
i = block1.inputargs.index(v)
v = link.args[i]
outputargs.append(v)
link.args = outputargs
link.target = exit.target
# the while loop above will simplify recursively the new link
traverse(visit, graph)
def eliminate_empty_blocks(graph):
"""Eliminate basic blocks that do not contain any operations.
When this happens, we need to replace the preceeding link with the
following link. Arguments of the links should be updated."""
def visit(link):
if isinstance(link, Link):
while not link.target.operations:
block1 = link.target
if block1.exitswitch is not None:
break
if not block1.exits:
break
exit = block1.exits[0]
assert block1 is not exit.target, (
"the graph contains an empty infinite loop")
outputargs = []
for v in exit.args:
if isinstance(v, Variable):
# this variable is valid in the context of block1
# but it must come from 'link'
i = block1.inputargs.index(v)
v = link.args[i]
outputargs.append(v)
link.args = outputargs
link.target = exit.target
# the while loop above will simplify recursively the new link
traverse(visit, graph)
def test_frozen_user_class1(self):
class C:
def __nonzero__(self):
return True
def _freeze_(self):
return True
c = C()
def f():
if c:
return 1
else:
return 2
graph = self.codetest(f)
results = []
def visit(link):
if isinstance(link, Link):
if link.target == graph.returnblock:
results.extend(link.args)
traverse(visit, graph)
assert len(results) == 1
def remove_dead_exceptions(graph):
"""Exceptions can be removed if they are unreachable"""
clastexc = c_last_exception
def issubclassofmember(cls, seq):
for member in seq:
if member and issubclass(cls, member):
return True
return False
def visit(block):
if not (isinstance(block, Block) and block.exitswitch == clastexc):
return
exits = []
seen = []
for link in block.exits:
case = link.exitcase
# check whether exceptions are shadowed
if issubclassofmember(case, seen):
continue
# see if the previous case can be merged
while len(exits) > 1:
prev = exits[-1]
if not (issubclass(prev.exitcase, link.exitcase) and
prev.target is link.target and prev.args == link.args):
break
exits.pop()
exits.append(link)
seen.append(case)
block.recloseblock(*exits)
traverse(visit, graph)
def test_implicitAttributeError(self):
x = self.codetest(self.implicitAttributeError)
simplify_graph(x)
self.show(x)
def cannot_reach_exceptblock(link):
if isinstance(link, Link):
assert link.target is not x.exceptblock
traverse(cannot_reach_exceptblock, x)
def all_operations(self, graph):
result = {}
def visit(node):
if isinstance(node, Block):
for op in node.operations:
result.setdefault(op.opname, 0)
result[op.opname] += 1
traverse(visit, graph)
return result
def transform_dead_op_vars(graph, translator=None):
"""Remove dead operations and variables that are passed over a link
but not used in the target block. Input is a graph."""
blocks = {}
def visit(block):
if isinstance(block, Block):
blocks[block] = True
traverse(visit, graph)
return transform_dead_op_vars_in_blocks(blocks, translator)
def transform_dead_op_vars(graph, translator=None):
"""Remove dead operations and variables that are passed over a link
but not used in the target block. Input is a graph."""
blocks = {}
def visit(block):
if isinstance(block, Block):
blocks[block] = True
traverse(visit, graph)
return transform_dead_op_vars_in_blocks(blocks, translator)
def test_reraiseTypeError(self):
x = self.codetest(self.reraiseTypeError)
simplify_graph(x)
self.show(x)
found = []
def can_reach_exceptblock(link):
if isinstance(link, Link):
if link.target is x.exceptblock:
found.append(link)
traverse(can_reach_exceptblock, x)
assert found
def test_reraiseAnything(self):
x = self.codetest(self.reraiseAnything)
simplify_graph(x)
self.show(x)
found = {}
def find_exceptions(link):
if isinstance(link, Link):
if link.target is x.exceptblock:
assert isinstance(link.args[0], Constant)
found[link.args[0].value] = True
traverse(find_exceptions, x)
assert found == {ValueError: True, ZeroDivisionError: True, OverflowError: True}
def test_reraiseAttributeError(self):
x = self.codetest(self.reraiseAttributeError)
simplify_graph(x)
self.show(x)
found_AttributeError = []
def only_raise_AttributeError(link):
if isinstance(link, Link):
if link.target is x.exceptblock:
assert link.args[0] == Constant(AttributeError)
found_AttributeError.append(link)
traverse(only_raise_AttributeError, x)
assert found_AttributeError
def coalesce_is_true(graph):
"""coalesce paths that go through an is_true and a directly successive
is_true both on the same value, transforming the link into the
second is_true from the first to directly jump to the correct
target out of the second."""
if simplify_disabled(graph): return
candidates = []
def has_is_true_exitpath(block):
tgts = []
start_op = block.operations[-1]
cond_v = start_op.args[0]
if block.exitswitch == start_op.result:
for exit in block.exits:
tgt = exit.target
if tgt == block:
continue
rrenaming = dict(zip(tgt.inputargs, exit.args))
if len(tgt.operations
) == 1 and tgt.operations[0].opname == 'is_true':
tgt_op = tgt.operations[0]
if tgt.exitswitch == tgt_op.result and rrenaming.get(
tgt_op.args[0]) == cond_v:
tgts.append((exit.exitcase, tgt))
return tgts
def visit(block):
if isinstance(
block, Block
) and block.operations and block.operations[-1].opname == 'is_true':
tgts = has_is_true_exitpath(block)
if tgts:
candidates.append((block, tgts))
traverse(visit, graph)
while candidates:
cand, tgts = candidates.pop()
newexits = list(cand.exits)
for case, tgt in tgts:
exit = cand.exits[case]
rrenaming = dict(zip(tgt.inputargs, exit.args))
rrenaming[tgt.operations[0].result] = cand.operations[-1].result
def rename(v):
return rrenaming.get(v, v)
newlink = tgt.exits[case].copy(rename)
newexits[case] = newlink
cand.recloseblock(*newexits)
newtgts = has_is_true_exitpath(cand)
if newtgts:
candidates.append((cand, newtgts))
def test_reraiseTypeError(self):
x = self.codetest(self.reraiseTypeError)
simplify_graph(x)
self.show(x)
found = []
def can_reach_exceptblock(link):
if isinstance(link, Link):
if link.target is x.exceptblock:
found.append(link)
traverse(can_reach_exceptblock, x)
assert found
def test_const_star_call(self):
def g(a=1,b=2,c=3):
pass
def f():
return g(1,*(2,3))
graph = self.codetest(f)
call_args = []
def visit(block):
if isinstance(block, Block):
for op in block.operations:
if op.opname == "call_args":
call_args.append(op)
traverse(visit, graph)
assert not call_args
def test_reraiseAnythingDicCase(self):
x = self.codetest(self.reraiseAnythingDicCase)
simplify_graph(x)
self.show(x)
found = {}
def find_exceptions(link):
if isinstance(link, Link):
if link.target is x.exceptblock:
if isinstance(link.args[0], Constant):
found[link.args[0].value] = True
else:
found[link.exitcase] = None
traverse(find_exceptions, x)
assert found == {IndexError: True, KeyError: True, Exception: None}
def graph_footprint(graph):
class Counter:
blocks = 0
links = 0
ops = 0
count = Counter()
def visit(block):
if isinstance(block, flowmodel.Block):
count.blocks += 1
count.ops += len(block.operations)
elif isinstance(block, flowmodel.Link):
count.links += 1
flowmodel.traverse(visit, graph)
return count.blocks, count.links, count.ops
def test_reraiseAttributeError(self):
x = self.codetest(self.reraiseAttributeError)
simplify_graph(x)
self.show(x)
found_AttributeError = []
def only_raise_AttributeError(link):
if isinstance(link, Link):
if link.target is x.exceptblock:
assert link.args[0] == Constant(AttributeError)
found_AttributeError.append(link)
traverse(only_raise_AttributeError, x)
assert found_AttributeError
def test_reraiseTypeError(self):
x = self.codetest(self.reraiseTypeError)
simplify_graph(x)
self.show(x)
excfound = []
def check(link):
if isinstance(link, Link):
if link.target is x.exceptblock:
excfound.append(link.exitcase)
traverse(check, x)
assert len(excfound) == 2
excfound.sort()
expected = [Exception, TypeError]
expected.sort()
assert excfound == expected
def coalesce_is_true(graph):
"""coalesce paths that go through an is_true and a directly successive
is_true both on the same value, transforming the link into the
second is_true from the first to directly jump to the correct
target out of the second."""
candidates = []
def has_is_true_exitpath(block):
tgts = []
start_op = block.operations[-1]
cond_v = start_op.args[0]
if block.exitswitch == start_op.result:
for exit in block.exits:
tgt = exit.target
if tgt == block:
continue
rrenaming = dict(zip(tgt.inputargs, exit.args))
if len(tgt.operations) == 1 and tgt.operations[0].opname == "is_true":
tgt_op = tgt.operations[0]
if tgt.exitswitch == tgt_op.result and rrenaming.get(tgt_op.args[0]) == cond_v:
tgts.append((exit.exitcase, tgt))
return tgts
def visit(block):
if isinstance(block, Block) and block.operations and block.operations[-1].opname == "is_true":
tgts = has_is_true_exitpath(block)
if tgts:
candidates.append((block, tgts))
traverse(visit, graph)
while candidates:
cand, tgts = candidates.pop()
newexits = list(cand.exits)
for case, tgt in tgts:
exit = cand.exits[case]
rrenaming = dict(zip(tgt.inputargs, exit.args))
rrenaming[tgt.operations[0].result] = cand.operations[-1].result
def rename(v):
return rrenaming.get(v, v)
newlink = tgt.exits[case].copy(rename)
newexits[case] = newlink
cand.recloseblock(*newexits)
newtgts = has_is_true_exitpath(cand)
if newtgts:
candidates.append((cand, newtgts))
def patch_graphs(self):
def patch_consts(args):
for arg in args:
if isinstance(arg, Constant) and arg in self.constants:
arg.value = self.constants[arg]
def visit(obj):
if isinstance(obj, Link):
patch_consts(obj.args)
if (hasattr(obj, "llexitcase") and
Constant(obj.llexitcase) in self.constants):
obj.llexitcase = self.constants[Constant(obj.llexitcase)]
elif isinstance(obj, Block):
for op in obj.operations:
patch_consts(op.args)
for graph in self.graphs:
traverse(visit, graph)
def graph_footprint(graph):
class Counter:
blocks = 0
links = 0
ops = 0
count = Counter()
def visit(block):
if isinstance(block, flowmodel.Block):
count.blocks += 1
count.ops += len(block.operations)
elif isinstance(block, flowmodel.Link):
count.links += 1
flowmodel.traverse(visit, graph)
return count.blocks, count.links, count.ops
def ordered_blocks(graph):
# collect all blocks
allblocks = []
def visit(block):
if isinstance(block, Block):
# first we order by offset in the code string
if block.operations:
ofs = block.operations[0].offset
else:
ofs = sys.maxint
# then we order by input variable name or value
if block.inputargs:
txt = str(block.inputargs[0])
else:
txt = "dummy"
allblocks.append((ofs, txt, block))
traverse(visit, graph)
allblocks.sort()
#for ofs, txt, block in allblocks:
# print ofs, txt, block
return [block for ofs, txt, block in allblocks]
def ordered_blocks(graph):
# collect all blocks
allblocks = []
def visit(block):
if isinstance(block, Block):
# first we order by offset in the code string
if block.operations:
ofs = block.operations[0].offset
else:
ofs = sys.maxint
# then we order by input variable name or value
if block.inputargs:
txt = str(block.inputargs[0])
else:
txt = "dummy"
allblocks.append((ofs, txt, block))
traverse(visit, graph)
allblocks.sort()
#for ofs, txt, block in allblocks:
# print ofs, txt, block
return [block for ofs, txt, block in allblocks]
def compute_lifetimes(self, graph):
"""Compute the static data flow of the graph: returns a list of LifeTime
instances, each of which corresponds to a set of Variables from the graph.
The variables are grouped in the same LifeTime if a value can pass from
one to the other by following the links. Each LifeTime also records all
places where a Variable in the set is used (read) or build (created).
"""
lifetimes = UnionFind(LifeTime)
def set_creation_point(block, var, *cp):
_, _, info = lifetimes.find((block, var))
info.creationpoints[cp] = True
def set_use_point(block, var, *up):
_, _, info = lifetimes.find((block, var))
info.usepoints[up] = True
def union(block1, var1, block2, var2):
if isinstance(var1, Variable):
lifetimes.union((block1, var1), (block2, var2))
elif isinstance(var1, Constant):
set_creation_point(block2, var2, "constant", var1)
else:
raise TypeError(var1)
for var in graph.startblock.inputargs:
set_creation_point(graph.startblock, var, "inputargs")
set_use_point(graph.returnblock, graph.returnblock.inputargs[0], "return")
set_use_point(graph.exceptblock, graph.exceptblock.inputargs[0], "except")
set_use_point(graph.exceptblock, graph.exceptblock.inputargs[1], "except")
def visit(node):
if isinstance(node, Block):
for op in node.operations:
if op.opname in self.IDENTITY_OPS:
# special-case these operations to identify their input
# and output variables
union(node, op.args[0], node, op.result)
continue
if op.opname in self.SUBSTRUCT_OPS:
if self.visit_substruct_op(node, union, op):
continue
for i in range(len(op.args)):
if isinstance(op.args[i], Variable):
set_use_point(node, op.args[i], "op", node, op, i)
set_creation_point(node, op.result, "op", node, op)
if isinstance(node.exitswitch, Variable):
set_use_point(node, node.exitswitch, "exitswitch", node)
if isinstance(node, Link):
if isinstance(node.last_exception, Variable):
set_creation_point(node.prevblock, node.last_exception,
"last_exception")
if isinstance(node.last_exc_value, Variable):
set_creation_point(node.prevblock, node.last_exc_value,
"last_exc_value")
d = {}
for i, arg in enumerate(node.args):
union(node.prevblock, arg,
node.target, node.target.inputargs[i])
if isinstance(arg, Variable):
if arg in d:
# same variable present several times in link.args
# consider it as a 'use' of the variable, which
# will disable malloc optimization (aliasing problems)
set_use_point(node.prevblock, arg, "dup", node, i)
else:
d[arg] = True
traverse(visit, graph)
return lifetimes.infos()
def sanity_check(t):
# look for missing '.concretetype'
for graph in t.graphs:
checkgraph(graph)
traverse(no_missing_concretetype, graph)
def sanity_check(t):
# look for missing '.concretetype'
for graph in t.graphs:
checkgraph(graph)
traverse(no_missing_concretetype, graph)
def transform_ovfcheck(graph):
"""The special function calls ovfcheck and ovfcheck_lshift need to
be translated into primitive operations. ovfcheck is called directly
after an operation that should be turned into an overflow-checked
version. It is considered a syntax error if the resulting <op>-ovf
is not defined in baseobjspace.py .
ovfcheck_lshift is special because there is no preceding operation.
Instead, it will be replaced by an OP_LSHIFT_OVF operation.
The exception handling of the original operation is completely
ignored. Only exception handlers for the ovfcheck function call
are taken into account. This gives us the best possible control
over situations where we want exact contol over certain operations.
Example:
try:
array1[idx-1] = ovfcheck(array1[idx-1] + array2[idx+1])
except OverflowError:
...
assuming two integer arrays, we are only checking the element addition
for overflows, but the indexing is not checked.
"""
# General assumption:
# empty blocks have been eliminated.
# ovfcheck can appear in the same block with its operation.
# this is the case if no exception handling was provided.
# Otherwise, we have a block ending in the operation,
# followed by a block with a single ovfcheck call.
from pypy.rlib.rarithmetic import ovfcheck, ovfcheck_lshift
from pypy.objspace.flow.objspace import op_appendices
from pypy.objspace.flow.objspace import implicit_exceptions
covf = Constant(ovfcheck)
covfls = Constant(ovfcheck_lshift)
appendix = op_appendices[OverflowError]
renaming = {}
seen_ovfblocks = {}
# get all blocks
blocks = {}
def visit(block):
if isinstance(block, Block):
blocks[block] = True
traverse(visit, graph)
def is_ovfcheck(bl):
ops = bl.operations
return ops and ops[-1].opname == "simple_call" and ops[-1].args[0] == covf
def is_ovfshiftcheck(bl):
ops = bl.operations
return ops and ops[-1].opname == "simple_call" and ops[-1].args[0] == covfls
def is_single(bl):
return is_ovfcheck(bl) and len(bl.operations) > 1
def is_paired(bl):
if bl.exits:
ovfblock = bl.exits[0].target
return bl.exits and is_ovfcheck(ovfblock) and len(ovfblock.operations) == 1
def rename(v):
return renaming.get(v, v)
def remove_last_op(bl):
delop = bl.operations.pop()
assert delop.opname == "simple_call"
assert len(delop.args) == 2
renaming[delop.result] = rename(delop.args[1])
for exit in bl.exits:
exit.args = [rename(a) for a in exit.args]
def check_syntax(ovfblock, block=None):
"""check whether ovfblock is reachable more than once
or if they cheated about the argument"""
if block:
link = block.exits[0]
for lprev, ltarg in zip(link.args, ovfblock.inputargs):
renaming[ltarg] = rename(lprev)
arg = ovfblock.operations[0].args[-1]
res = block.operations[-1].result
opname = block.operations[-1].opname
else:
arg = ovfblock.operations[-1].args[-1]
res = ovfblock.operations[-2].result
opname = ovfblock.operations[-2].opname
if rename(arg) != rename(res) or ovfblock in seen_ovfblocks:
raise SyntaxError("ovfcheck in %s: The checked operation %s" " is misplaced" % (graph.name, opname))
exlis = implicit_exceptions.get("%s_%s" % (opname, appendix), [])
if OverflowError not in exlis:
raise SyntaxError("ovfcheck in %s: Operation %s has no" " overflow variant" % (graph.name, opname))
blocks_to_join = False
for block in blocks:
if is_ovfshiftcheck(block):
# ovfcheck_lshift:
# simply rewrite the operation
op = block.operations[-1]
op.opname = "lshift" # augmented later
op.args = op.args[1:]
elif is_single(block):
# remove the call to ovfcheck and keep the exceptions
check_syntax(block)
remove_last_op(block)
seen_ovfblocks[block] = True
elif is_paired(block):
# remove the block's exception links
link = block.exits[0]
ovfblock = link.target
check_syntax(ovfblock, block)
block.recloseblock(link)
block.exitswitch = None
# remove the ovfcheck call from the None target
remove_last_op(ovfblock)
seen_ovfblocks[ovfblock] = True
blocks_to_join = True
else:
continue
op = block.operations[-1]
op.opname = "%s_%s" % (op.opname, appendix)
if blocks_to_join:
join_blocks(graph)
def simplify_exceptions(graph):
"""The exception handling caused by non-implicit exceptions
starts with an exitswitch on Exception, followed by a lengthy
chain of is_/issubtype tests. We collapse them all into
the block's single list of exits.
"""
clastexc = c_last_exception
renaming = {}
def rename(v):
return renaming.get(v, v)
def visit(block):
if not (isinstance(block, Block)
and block.exitswitch == clastexc
and block.exits[-1].exitcase is Exception):
return
covered = [link.exitcase for link in block.exits[1:-1]]
seen = []
preserve = list(block.exits[:-1])
exc = block.exits[-1]
last_exception = exc.last_exception
last_exc_value = exc.last_exc_value
query = exc.target
switches = []
# collect the targets
while len(query.exits) == 2:
newrenaming = {}
for lprev, ltarg in zip(exc.args, query.inputargs):
newrenaming[ltarg] = rename(lprev)
op = query.operations[0]
if not (op.opname in ("is_", "issubtype") and
newrenaming.get(op.args[0]) == last_exception):
break
renaming.update(newrenaming)
case = query.operations[0].args[-1].value
assert issubclass(case, py.builtin.BaseException)
lno, lyes = query.exits
assert lno.exitcase == False and lyes.exitcase == True
if case not in seen:
is_covered = False
for cov in covered:
if issubclass(case, cov):
is_covered = True
break
if not is_covered:
switches.append( (case, lyes) )
seen.append(case)
exc = lno
query = exc.target
if Exception not in seen:
switches.append( (Exception, exc) )
# construct the block's new exits
exits = []
for case, oldlink in switches:
link = oldlink.copy(rename)
assert case is not None
link.last_exception = last_exception
link.last_exc_value = last_exc_value
# make the above two variables unique
renaming2 = {}
def rename2(v):
return renaming2.get(v, v)
for v in link.getextravars():
renaming2[v] = Variable(v)
link = link.copy(rename2)
link.exitcase = case
link.prevblock = block
exits.append(link)
block.recloseblock(*(preserve + exits))
traverse(visit, graph)
def compute_lifetimes(self, graph):
"""Compute the static data flow of the graph: returns a list of LifeTime
instances, each of which corresponds to a set of Variables from the graph.
The variables are grouped in the same LifeTime if a value can pass from
one to the other by following the links. Each LifeTime also records all
places where a Variable in the set is used (read) or build (created).
"""
lifetimes = UnionFind(LifeTime)
def set_creation_point(block, var, *cp):
_, _, info = lifetimes.find((block, var))
info.creationpoints[cp] = True
def set_use_point(block, var, *up):
_, _, info = lifetimes.find((block, var))
info.usepoints[up] = True
def union(block1, var1, block2, var2):
if isinstance(var1, Variable):
lifetimes.union((block1, var1), (block2, var2))
elif isinstance(var1, Constant):
set_creation_point(block2, var2, "constant", var1)
else:
raise TypeError(var1)
for var in graph.startblock.inputargs:
set_creation_point(graph.startblock, var, "inputargs")
set_use_point(graph.returnblock, graph.returnblock.inputargs[0],
"return")
set_use_point(graph.exceptblock, graph.exceptblock.inputargs[0],
"except")
set_use_point(graph.exceptblock, graph.exceptblock.inputargs[1],
"except")
def visit(node):
if isinstance(node, Block):
for op in node.operations:
if op.opname in self.IDENTITY_OPS:
# special-case these operations to identify their input
# and output variables
union(node, op.args[0], node, op.result)
continue
if op.opname in self.SUBSTRUCT_OPS:
if self.visit_substruct_op(node, union, op):
continue
for i in range(len(op.args)):
if isinstance(op.args[i], Variable):
set_use_point(node, op.args[i], "op", node, op, i)
set_creation_point(node, op.result, "op", node, op)
if isinstance(node.exitswitch, Variable):
set_use_point(node, node.exitswitch, "exitswitch", node)
if isinstance(node, Link):
if isinstance(node.last_exception, Variable):
set_creation_point(node.prevblock, node.last_exception,
"last_exception")
if isinstance(node.last_exc_value, Variable):
set_creation_point(node.prevblock, node.last_exc_value,
"last_exc_value")
d = {}
for i, arg in enumerate(node.args):
union(node.prevblock, arg, node.target,
node.target.inputargs[i])
if isinstance(arg, Variable):
if arg in d:
# same variable present several times in link.args
# consider it as a 'use' of the variable, which
# will disable malloc optimization (aliasing problems)
set_use_point(node.prevblock, arg, "dup", node, i)
else:
d[arg] = True
traverse(visit, graph)
return lifetimes.infos()
link.last_exc_value = last_exc_value
# make the above two variables unique
renaming2 = {}
def rename2(v):
return renaming2.get(v, v)
for v in link.getextravars():
renaming2[v] = Variable(v)
link = link.copy(rename2)
link.exitcase = case
link.prevblock = block
exits.append(link)
block.recloseblock(*(preserve + exits))
traverse(visit, graph)
def transform_xxxitem(graph):
# xxx setitem too
if simplify_disabled(graph): return
for block in graph.iterblocks():
if block.operations and block.exitswitch == c_last_exception:
last_op = block.operations[-1]
if last_op.opname == 'getitem':
postfx = []
for exit in block.exits:
if exit.exitcase is IndexError:
postfx.append('idx')
elif exit.exitcase is KeyError:
postfx.append('key')
def transform_ovfcheck(graph):
"""The special function calls ovfcheck and ovfcheck_lshift need to
be translated into primitive operations. ovfcheck is called directly
after an operation that should be turned into an overflow-checked
version. It is considered a syntax error if the resulting <op>-ovf
is not defined in baseobjspace.py .
ovfcheck_lshift is special because there is no preceding operation.
Instead, it will be replaced by an OP_LSHIFT_OVF operation.
The exception handling of the original operation is completely
ignored. Only exception handlers for the ovfcheck function call
are taken into account. This gives us the best possible control
over situations where we want exact contol over certain operations.
Example:
try:
array1[idx-1] = ovfcheck(array1[idx-1] + array2[idx+1])
except OverflowError:
...
assuming two integer arrays, we are only checking the element addition
for overflows, but the indexing is not checked.
"""
# General assumption:
# empty blocks have been eliminated.
# ovfcheck can appear in the same block with its operation.
# this is the case if no exception handling was provided.
# Otherwise, we have a block ending in the operation,
# followed by a block with a single ovfcheck call.
if simplify_disabled(graph): return
from pypy.rlib.rarithmetic import ovfcheck, ovfcheck_lshift
from pypy.objspace.flow.objspace import op_appendices
from pypy.objspace.flow.objspace import implicit_exceptions
covf = Constant(ovfcheck)
covfls = Constant(ovfcheck_lshift)
appendix = op_appendices[OverflowError]
renaming = {}
seen_ovfblocks = {}
# get all blocks
blocks = {}
def visit(block):
if isinstance(block, Block):
blocks[block] = True
traverse(visit, graph)
def is_ovfcheck(bl):
ops = bl.operations
return (ops and ops[-1].opname == "simple_call"
and ops[-1].args[0] == covf)
def is_ovfshiftcheck(bl):
ops = bl.operations
return (ops and ops[-1].opname == "simple_call"
and ops[-1].args[0] == covfls)
def is_single(bl):
return is_ovfcheck(bl) and len(bl.operations) > 1
def is_paired(bl):
if bl.exits:
ovfblock = bl.exits[0].target
return (bl.exits and is_ovfcheck(ovfblock)
and len(ovfblock.operations) == 1)
def rename(v):
return renaming.get(v, v)
def remove_last_op(bl):
delop = bl.operations.pop()
assert delop.opname == "simple_call"
assert len(delop.args) == 2
renaming[delop.result] = rename(delop.args[1])
for exit in bl.exits:
exit.args = [rename(a) for a in exit.args]
def check_syntax(ovfblock, block=None):
"""check whether ovfblock is reachable more than once
or if they cheated about the argument"""
if block:
link = block.exits[0]
for lprev, ltarg in zip(link.args, ovfblock.inputargs):
renaming[ltarg] = rename(lprev)
arg = ovfblock.operations[0].args[-1]
res = block.operations[-1].result
opname = block.operations[-1].opname
else:
arg = ovfblock.operations[-1].args[-1]
res = ovfblock.operations[-2].result
opname = ovfblock.operations[-2].opname
if rename(arg) != rename(res) or ovfblock in seen_ovfblocks:
raise SyntaxError("ovfcheck in %s: The checked operation %s"
" is misplaced" % (graph.name, opname))
exlis = implicit_exceptions.get("%s_%s" % (opname, appendix), [])
if OverflowError not in exlis:
raise SyntaxError("ovfcheck in %s: Operation %s has no"
" overflow variant" % (graph.name, opname))
blocks_to_join = False
for block in blocks:
if is_ovfshiftcheck(block):
# ovfcheck_lshift:
# simply rewrite the operation
op = block.operations[-1]
op.opname = "lshift" # augmented later
op.args = op.args[1:]
elif is_single(block):
# remove the call to ovfcheck and keep the exceptions
check_syntax(block)
remove_last_op(block)
seen_ovfblocks[block] = True
elif is_paired(block):
# remove the block's exception links
link = block.exits[0]
ovfblock = link.target
check_syntax(ovfblock, block)
block.recloseblock(link)
block.exitswitch = None
# remove the ovfcheck call from the None target
remove_last_op(ovfblock)
seen_ovfblocks[ovfblock] = True
blocks_to_join = True
else:
continue
op = block.operations[-1]
op.opname = "%s_%s" % (op.opname, appendix)
if blocks_to_join:
join_blocks(graph)
