def preprocess_kernel(kernel, device=None):
if device is not None:
from warnings import warn
warn("passing 'device' to preprocess_kernel() is deprecated",
DeprecationWarning, stacklevel=2)
from loopy.kernel import kernel_state
if kernel.state != kernel_state.INITIAL:
raise LoopyError("cannot re-preprocess an already preprocessed "
"kernel")
# {{{ cache retrieval
from loopy import CACHING_ENABLED
if CACHING_ENABLED:
input_kernel = kernel
try:
result = preprocess_cache[kernel]
logger.info("%s: preprocess cache hit" % kernel.name)
return result
except KeyError:
pass
# }}}
logger.info("%s: preprocess start" % kernel.name)
from loopy.subst import expand_subst
kernel = expand_subst(kernel)
# Ordering restriction:
# Type inference doesn't handle substitutions. Get them out of the
# way.
kernel = infer_unknown_types(kernel, expect_completion=False)
kernel = add_default_dependencies(kernel)
# Ordering restrictions:
#
# - realize_reduction must happen after type inference because it needs
# to be able to determine the types of the reduced expressions.
#
# - realize_reduction must happen after default dependencies are added
# because it manipulates the insn_deps field, which could prevent
# defaults from being applied.
kernel = realize_reduction(kernel)
# Ordering restriction:
# duplicate_private_temporaries_for_ilp because reduction accumulators
# need to be duplicated by this.
kernel = duplicate_private_temporaries_for_ilp_and_vec(kernel)
kernel = mark_local_temporaries(kernel)
kernel = assign_automatic_axes(kernel)
kernel = find_boostability(kernel)
kernel = limit_boostability(kernel)
kernel = kernel.target.preprocess(kernel)
logger.info("%s: preprocess done" % kernel.name)
kernel = kernel.copy(
state=kernel_state.PREPROCESSED)
# {{{ prepare for caching
# PicklableDtype instances for example need to know the target they're working
# towards in order to pickle and unpickle them. This is the first pass that
# uses caching, so we need to be ready to pickle. This means propagating
# this target information.
if CACHING_ENABLED:
input_kernel = prepare_for_caching(input_kernel)
kernel = prepare_for_caching(kernel)
# }}}
if CACHING_ENABLED:
preprocess_cache[input_kernel] = kernel
return kernel
def infer_unknown_types(kernel, expect_completion=False):
"""Infer types on temporaries and arguments."""
logger.debug("%s: infer types" % kernel.name)
def debug(s):
logger.debug("%s: %s" % (kernel.name, s))
unexpanded_kernel = kernel
if kernel.substitutions:
from loopy.subst import expand_subst
kernel = expand_subst(kernel)
new_temp_vars = kernel.temporary_variables.copy()
new_arg_dict = kernel.arg_dict.copy()
# {{{ fill queue
# queue contains temporary variables
queue = []
import loopy as lp
for tv in six.itervalues(kernel.temporary_variables):
if tv.dtype is lp.auto:
queue.append(tv)
for arg in kernel.args:
if arg.dtype is None:
queue.append(arg)
# }}}
from loopy.expression import TypeInferenceMapper
type_inf_mapper = TypeInferenceMapper(kernel,
_DictUnionView([
new_temp_vars,
new_arg_dict
]))
from loopy.symbolic import SubstitutionRuleExpander
subst_expander = SubstitutionRuleExpander(kernel.substitutions)
# {{{ work on type inference queue
from loopy.kernel.data import TemporaryVariable, KernelArgument
failed_names = set()
while queue:
item = queue.pop(0)
debug("inferring type for %s %s" % (type(item).__name__, item.name))
result, symbols_with_unavailable_types = \
_infer_var_type(kernel, item.name, type_inf_mapper, subst_expander)
failed = result is None
if not failed:
debug(" success: %s" % result)
if isinstance(item, TemporaryVariable):
new_temp_vars[item.name] = item.copy(dtype=result)
elif isinstance(item, KernelArgument):
new_arg_dict[item.name] = item.copy(dtype=result)
else:
raise LoopyError("unexpected item type in type inference")
else:
debug(" failure")
if failed:
if item.name in failed_names:
# this item has failed before, give up.
advice = ""
if symbols_with_unavailable_types:
advice += (
" (need type of '%s'--check for missing arguments)"
% ", ".join(symbols_with_unavailable_types))
if expect_completion:
raise LoopyError(
"could not determine type of '%s'%s"
% (item.name, advice))
else:
# We're done here.
break
# remember that this item failed
failed_names.add(item.name)
queue_names = set(qi.name for qi in queue)
if queue_names == failed_names:
# We did what we could...
print(queue_names, failed_names, item.name)
assert not expect_completion
break
# can't infer type yet, put back into queue
queue.append(item)
else:
# we've made progress, reset failure markers
failed_names = set()
# }}}
return unexpanded_kernel.copy(
temporary_variables=new_temp_vars,
args=[new_arg_dict[arg.name] for arg in kernel.args],
)
def find_all_insn_inames(kernel):
logger.debug("%s: find_all_insn_inames: start" % kernel.name)
writer_map = kernel.writer_map()
insn_id_to_inames = {}
insn_assignee_inames = {}
all_read_deps = {}
all_write_deps = {}
from loopy.subst import expand_subst
kernel = expand_subst(kernel)
for insn in kernel.instructions:
all_read_deps[insn.id] = read_deps = insn.read_dependency_names()
all_write_deps[insn.id] = write_deps = insn.write_dependency_names()
deps = read_deps | write_deps
if insn.forced_iname_deps_is_final:
iname_deps = insn.forced_iname_deps
else:
iname_deps = (
deps & kernel.all_inames()
| insn.forced_iname_deps)
assert isinstance(read_deps, frozenset), type(insn)
assert isinstance(write_deps, frozenset), type(insn)
assert isinstance(iname_deps, frozenset), type(insn)
logger.debug("%s: find_all_insn_inames: %s (init): %s - "
"read deps: %s - write deps: %s" % (
kernel.name, insn.id, ", ".join(sorted(iname_deps)),
", ".join(sorted(read_deps)), ", ".join(sorted(write_deps)),
))
insn_id_to_inames[insn.id] = iname_deps
insn_assignee_inames[insn.id] = write_deps & kernel.all_inames()
written_vars = kernel.get_written_variables()
# fixed point iteration until all iname dep sets have converged
# Why is fixed point iteration necessary here? Consider the following
# scenario:
#
# z = expr(iname)
# y = expr(z)
# x = expr(y)
#
# x clearly has a dependency on iname, but this is not found until that
# dependency has propagated all the way up. Doing this recursively is
# not guaranteed to terminate because of circular dependencies.
while True:
did_something = False
for insn in kernel.instructions:
if insn.forced_iname_deps_is_final:
continue
# {{{ depdency-based propagation
# For all variables that insn depends on, find the intersection
# of iname deps of all writers, and add those to insn's
# dependencies.
for tv_name in (all_read_deps[insn.id] & written_vars):
implicit_inames = None
for writer_id in writer_map[tv_name]:
writer_implicit_inames = (
insn_id_to_inames[writer_id]
- insn_assignee_inames[writer_id])
if implicit_inames is None:
implicit_inames = writer_implicit_inames
else:
implicit_inames = (implicit_inames
& writer_implicit_inames)
inames_old = insn_id_to_inames[insn.id]
inames_new = (inames_old | implicit_inames) \
- insn.reduction_inames()
insn_id_to_inames[insn.id] = inames_new
if inames_new != inames_old:
did_something = True
logger.debug("%s: find_all_insn_inames: %s -> %s (dep-based)" % (
kernel.name, insn.id, ", ".join(sorted(inames_new))))
# }}}
# {{{ domain-based propagation
inames_old = insn_id_to_inames[insn.id]
inames_new = set(insn_id_to_inames[insn.id])
for iname in inames_old:
home_domain = kernel.domains[kernel.get_home_domain_index(iname)]
for par in home_domain.get_var_names(dim_type.param):
# Add all inames occurring in parameters of domains that my
# current inames refer to.
if par in kernel.all_inames():
inames_new.add(par)
# If something writes the bounds of a loop in which I'm
# sitting, I had better be in the inames that the writer is
# in.
if par in kernel.temporary_variables:
for writer_id in writer_map.get(par, []):
inames_new.update(insn_id_to_inames[writer_id])
if inames_new != inames_old:
did_something = True
insn_id_to_inames[insn.id] = frozenset(inames_new)
logger.debug("%s: find_all_insn_inames: %s -> %s (domain-based)" % (
kernel.name, insn.id, ", ".join(sorted(inames_new))))
# }}}
if not did_something:
break
logger.debug("%s: find_all_insn_inames: done" % kernel.name)
for v in six.itervalues(insn_id_to_inames):
assert isinstance(v, frozenset)
return insn_id_to_inames
