def map_array_access(self, index, expn_state):
accdesc = AccessDescriptor(identifier=None, storage_axis_exprs=index)
if not self.array_base_map.is_access_descriptor_in_footprint(accdesc):
return None
abm = self.array_base_map
index = expn_state.apply_arg_context(index)
assert len(index) == len(abm.non1_storage_axis_flags)
access_subscript = []
for i in range(len(index)):
if not abm.non1_storage_axis_flags[i]:
continue
ax_index = index[i]
from loopy.isl_helpers import simplify_via_aff
ax_index = simplify_via_aff(ax_index - abm.storage_base_indices[i])
access_subscript.append(ax_index)
result = self.buf_var
if access_subscript:
result = result.index(tuple(access_subscript))
# Can't possibly be nested, but recurse anyway to
# make sure substitution rules referenced below here
# do not get thrown away.
self.rec(result, expn_state.copy(arg_context={}))
return result
def map_substitution(self, name, tag, arguments, expn_state):
if not (name == self.subst_name and self.within(
expn_state.kernel, expn_state.instruction, expn_state.stack)
and (self.subst_tag is None or self.subst_tag == tag)):
return super(RuleInvocationReplacer,
self).map_substitution(name, tag, arguments,
expn_state)
# {{{ check if in footprint
rule = self.rule_mapping_context.old_subst_rules[name]
arg_context = self.make_new_arg_context(name, rule.arguments,
arguments,
expn_state.arg_context)
args = [arg_context[arg_name] for arg_name in rule.arguments]
accdesc = AccessDescriptor(storage_axis_exprs=storage_axis_exprs(
self.storage_axis_sources, args))
if not self.array_base_map.is_access_descriptor_in_footprint(accdesc):
return super(RuleInvocationReplacer,
self).map_substitution(name, tag, arguments,
expn_state)
# }}}
assert len(arguments) == len(rule.arguments)
abm = self.array_base_map
stor_subscript = []
for sax_name, sax_source, sax_base_idx in zip(
self.storage_axis_names, self.storage_axis_sources,
abm.storage_base_indices):
if sax_name not in self.non1_storage_axis_names:
continue
if isinstance(sax_source, int):
# an argument
ax_index = arguments[sax_source]
else:
# an iname
ax_index = var(sax_source)
from loopy.isl_helpers import simplify_via_aff
ax_index = simplify_via_aff(ax_index - sax_base_idx)
stor_subscript.append(ax_index)
new_outer_expr = var(self.temporary_name)
if stor_subscript:
new_outer_expr = new_outer_expr.index(tuple(stor_subscript))
# Can't possibly be nested, and no need to traverse
# further as compute expression has already been seen
# by rule_mapping_context.
self.replaced_something = True
return new_outer_expr
def buffer_array(kernel, var_name, buffer_inames, init_expression=None,
store_expression=None, within=None, default_tag="l.auto",
temporary_scope=None, temporary_is_local=None,
fetch_bounding_box=False):
"""Replace accesses to *var_name* with ones to a temporary, which is
created and acts as a buffer. To perform this transformation, the access
footprint to *var_name* is determined and a temporary of a suitable
:class:`loopy.AddressSpace` and shape is created.
By default, the value of the buffered cells in *var_name* are read prior to
any (read/write) use, and the modified values are written out after use has
concluded, but for special use cases (e.g. additive accumulation), the
behavior can be modified using *init_expression* and *store_expression*.
:arg buffer_inames: The inames across which the buffer should be usable--i.e.
all possible values of these inames will be covered by the buffer footprint.
A tuple of inames or a comma-separated string.
:arg init_expression: Either *None* (indicating the prior value of the buffered
array should be read) or an expression optionally involving the
variable 'base' (which references the associated location in the array
being buffered).
:arg store_expression: Either *None*, *False*, or an expression involving
variables 'base' and 'buffer' (without array indices).
(*None* indicates that a default storage instruction should be used,
*False* indicates that no storing of the temporary should occur
at all.)
:arg within: If not None, limit the action of the transformation to
matching contexts. See :func:`loopy.match.parse_stack_match`
for syntax.
:arg temporary_scope: If given, override the choice of
:class:`AddressSpace` for the created temporary.
:arg default_tag: The default :ref:`iname-tags` to be assigned to the
inames used for fetching and storing
:arg fetch_bounding_box: If the access footprint is non-convex
(resulting in an error), setting this argument to *True* will force a
rectangular (and hence convex) superset of the footprint to be
fetched.
"""
# {{{ unify temporary_scope / temporary_is_local
from loopy.kernel.data import AddressSpace
if temporary_is_local is not None:
from warnings import warn
warn("temporary_is_local is deprecated. Use temporary_scope instead",
DeprecationWarning, stacklevel=2)
if temporary_scope is not None:
raise LoopyError("may not specify both temporary_is_local and "
"temporary_scope")
if temporary_is_local:
temporary_scope = AddressSpace.LOCAL
else:
temporary_scope = AddressSpace.PRIVATE
del temporary_is_local
# }}}
# {{{ process arguments
if isinstance(init_expression, str):
from loopy.symbolic import parse
init_expression = parse(init_expression)
if isinstance(store_expression, str):
from loopy.symbolic import parse
store_expression = parse(store_expression)
if isinstance(buffer_inames, str):
buffer_inames = [s.strip()
for s in buffer_inames.split(",") if s.strip()]
for iname in buffer_inames:
if iname not in kernel.all_inames():
raise RuntimeError("sweep iname '%s' is not a known iname"
% iname)
buffer_inames = list(buffer_inames)
buffer_inames_set = frozenset(buffer_inames)
from loopy.match import parse_stack_match
within = parse_stack_match(within)
if var_name in kernel.arg_dict:
var_descr = kernel.arg_dict[var_name]
elif var_name in kernel.temporary_variables:
var_descr = kernel.temporary_variables[var_name]
else:
raise ValueError("variable '%s' not found" % var_name)
from loopy.kernel.data import ArrayBase
if isinstance(var_descr, ArrayBase):
var_shape = var_descr.shape
else:
var_shape = ()
if temporary_scope is None:
import loopy as lp
temporary_scope = lp.auto
# }}}
# {{{ caching
from loopy import CACHING_ENABLED
from loopy.preprocess import prepare_for_caching
key_kernel = prepare_for_caching(kernel)
cache_key = (key_kernel, var_name, tuple(buffer_inames),
PymbolicExpressionHashWrapper(init_expression),
PymbolicExpressionHashWrapper(store_expression), within,
default_tag, temporary_scope, fetch_bounding_box)
if CACHING_ENABLED:
try:
result = buffer_array_cache[cache_key]
logger.info("%s: buffer_array cache hit" % kernel.name)
return result
except KeyError:
pass
# }}}
var_name_gen = kernel.get_var_name_generator()
within_inames = set()
access_descriptors = []
for insn in kernel.instructions:
if not within(kernel, insn.id, ()):
continue
from pymbolic.primitives import Variable, Subscript
from loopy.symbolic import LinearSubscript
for assignee in insn.assignees:
if isinstance(assignee, Variable):
assignee_name = assignee.name
index = ()
elif isinstance(assignee, Subscript):
assignee_name = assignee.aggregate.name
index = assignee.index_tuple
elif isinstance(assignee, LinearSubscript):
if assignee.aggregate.name == var_name:
raise LoopyError("buffer_array may not be applied in the "
"presence of linear write indexing into '%s'" % var_name)
else:
raise LoopyError("invalid lvalue '%s'" % assignee)
if assignee_name == var_name:
within_inames.update(
(get_dependencies(index) & kernel.all_inames())
- buffer_inames_set)
access_descriptors.append(
AccessDescriptor(
identifier=insn.id,
storage_axis_exprs=index))
# {{{ find fetch/store inames
init_inames = []
store_inames = []
new_iname_to_tag = {}
for i in range(len(var_shape)):
dim_name = str(i)
if isinstance(var_descr, ArrayBase) and var_descr.dim_names is not None:
dim_name = var_descr.dim_names[i]
init_iname = var_name_gen(f"{var_name}_init_{dim_name}")
store_iname = var_name_gen(f"{var_name}_store_{dim_name}")
new_iname_to_tag[init_iname] = default_tag
new_iname_to_tag[store_iname] = default_tag
init_inames.append(init_iname)
store_inames.append(store_iname)
# }}}
# {{{ modify loop domain
non1_init_inames = []
non1_store_inames = []
if var_shape:
# {{{ find domain to be changed
from loopy.kernel.tools import DomainChanger
domch = DomainChanger(kernel, buffer_inames_set | within_inames)
if domch.leaf_domain_index is not None:
# If the sweep inames are at home in parent domains, then we'll add
# fetches with loops over copies of these parent inames that will end
# up being scheduled *within* loops over these parents.
for iname in buffer_inames_set:
if kernel.get_home_domain_index(iname) != domch.leaf_domain_index:
raise RuntimeError("buffer iname '%s' is not 'at home' in the "
"sweep's leaf domain" % iname)
# }}}
abm = ArrayToBufferMap(kernel, domch.domain, buffer_inames,
access_descriptors, len(var_shape))
for i in range(len(var_shape)):
if abm.non1_storage_axis_flags[i]:
non1_init_inames.append(init_inames[i])
non1_store_inames.append(store_inames[i])
else:
del new_iname_to_tag[init_inames[i]]
del new_iname_to_tag[store_inames[i]]
new_domain = domch.domain
new_domain = abm.augment_domain_with_sweep(
new_domain, non1_init_inames,
boxify_sweep=fetch_bounding_box)
new_domain = abm.augment_domain_with_sweep(
new_domain, non1_store_inames,
boxify_sweep=fetch_bounding_box)
new_kernel_domains = domch.get_domains_with(new_domain)
del new_domain
else:
# leave kernel domains unchanged
new_kernel_domains = kernel.domains
abm = NoOpArrayToBufferMap()
# }}}
# {{{ set up temp variable
import loopy as lp
buf_var_name = var_name_gen(based_on=var_name+"_buf")
new_temporary_variables = kernel.temporary_variables.copy()
temp_var = lp.TemporaryVariable(
name=buf_var_name,
dtype=var_descr.dtype,
base_indices=(0,)*len(abm.non1_storage_shape),
shape=tuple(abm.non1_storage_shape),
address_space=temporary_scope)
new_temporary_variables[buf_var_name] = temp_var
# }}}
new_insns = []
buf_var = var(buf_var_name)
# {{{ generate init instruction
buf_var_init = buf_var
if non1_init_inames:
buf_var_init = buf_var_init.index(
tuple(var(iname) for iname in non1_init_inames))
init_base = var(var_name)
init_subscript = []
init_iname_idx = 0
if var_shape:
for i in range(len(var_shape)):
ax_subscript = abm.storage_base_indices[i]
if abm.non1_storage_axis_flags[i]:
ax_subscript += var(non1_init_inames[init_iname_idx])
init_iname_idx += 1
init_subscript.append(ax_subscript)
if init_subscript:
init_base = init_base.index(tuple(init_subscript))
if init_expression is None:
init_expression = init_base
else:
init_expression = init_expression
init_expression = SubstitutionMapper(
make_subst_func({
"base": init_base,
}))(init_expression)
init_insn_id = kernel.make_unique_instruction_id(based_on="init_"+var_name)
from loopy.kernel.data import Assignment
init_instruction = Assignment(id=init_insn_id,
assignee=buf_var_init,
expression=init_expression,
within_inames=(
frozenset(within_inames)
| frozenset(non1_init_inames)),
depends_on=frozenset(),
depends_on_is_final=True)
# }}}
rule_mapping_context = SubstitutionRuleMappingContext(
kernel.substitutions, kernel.get_var_name_generator())
aar = ArrayAccessReplacer(rule_mapping_context, var_name,
within, abm, buf_var)
kernel = rule_mapping_context.finish_kernel(aar.map_kernel(kernel))
did_write = False
for insn_id in aar.modified_insn_ids:
insn = kernel.id_to_insn[insn_id]
if buf_var_name in insn.assignee_var_names():
did_write = True
# {{{ add init_insn_id to depends_on
new_insns = []
def none_to_empty_set(s):
if s is None:
return frozenset()
else:
return s
for insn in kernel.instructions:
if insn.id in aar.modified_insn_ids:
new_insns.append(
insn.copy(
depends_on=(
none_to_empty_set(insn.depends_on)
| frozenset([init_insn_id]))))
else:
new_insns.append(insn)
# }}}
# {{{ generate store instruction
buf_var_store = buf_var
if non1_store_inames:
buf_var_store = buf_var_store.index(
tuple(var(iname) for iname in non1_store_inames))
store_subscript = []
store_iname_idx = 0
if var_shape:
for i in range(len(var_shape)):
ax_subscript = abm.storage_base_indices[i]
if abm.non1_storage_axis_flags[i]:
ax_subscript += var(non1_store_inames[store_iname_idx])
store_iname_idx += 1
store_subscript.append(ax_subscript)
store_target = var(var_name)
if store_subscript:
store_target = store_target.index(tuple(store_subscript))
if store_expression is None:
store_expression = buf_var_store
else:
store_expression = SubstitutionMapper(
make_subst_func({
"base": store_target,
"buffer": buf_var_store,
}))(store_expression)
if store_expression is not False:
from loopy.kernel.data import Assignment
store_instruction = Assignment(
id=kernel.make_unique_instruction_id(based_on="store_"+var_name),
depends_on=frozenset(aar.modified_insn_ids),
no_sync_with=frozenset([(init_insn_id, "any")]),
assignee=store_target,
expression=store_expression,
within_inames=(
frozenset(within_inames)
| frozenset(non1_store_inames)))
else:
did_write = False
# }}}
new_insns.append(init_instruction)
if did_write:
new_insns.append(store_instruction)
else:
for iname in store_inames:
del new_iname_to_tag[iname]
kernel = kernel.copy(
domains=new_kernel_domains,
instructions=new_insns,
temporary_variables=new_temporary_variables)
from loopy import tag_inames
kernel = tag_inames(kernel, new_iname_to_tag)
from loopy.kernel.tools import assign_automatic_axes
kernel = assign_automatic_axes(kernel)
if CACHING_ENABLED:
from loopy.preprocess import prepare_for_caching
buffer_array_cache.store_if_not_present(
cache_key, prepare_for_caching(kernel))
return kernel