def map_reduction(expr, rec, nresults=1):
if frozenset(expr.inames) != inames_set:
return type(expr)(
operation=expr.operation,
inames=expr.inames,
expr=rec(expr.expr),
allow_simultaneous=expr.allow_simultaneous)
if subst_rule_name is None:
subst_rule_prefix = "red_%s_arg" % "_".join(inames)
my_subst_rule_name = var_name_gen(subst_rule_prefix)
else:
my_subst_rule_name = subst_rule_name
if my_subst_rule_name in substs:
raise LoopyError("substitution rule '%s' already exists"
% my_subst_rule_name)
from loopy.kernel.data import SubstitutionRule
substs[my_subst_rule_name] = SubstitutionRule(
name=my_subst_rule_name,
arguments=tuple(inames),
expression=expr.expr)
from pymbolic import var
iname_vars = [var(iname) for iname in inames]
return type(expr)(
operation=expr.operation,
inames=expr.inames,
expr=var(my_subst_rule_name)(*iname_vars),
allow_simultaneous=expr.allow_simultaneous)
def _get_new_substitutions_and_renames(self):
"""This makes a new dictionary of substitutions from the ones
encountered in mapping all the encountered expressions.
It tries hard to keep substitution names the same--i.e.
if all derivative versions of a substitution rule ended
up with the same mapped version, then this version should
retain the name that the substitution rule had previously.
Unfortunately, this can't be done in a single pass, and so
the routine returns an additional dictionary *subst_renames*
of renamings to be performed on the processed expressions.
The returned substitutions already have the rename applied
to them.
:returns: (new_substitutions, subst_renames)
"""
from loopy.kernel.data import SubstitutionRule
result = {}
renames = {}
used_names = set()
for key, (name, args, body) in six.iteritems(
self.subst_rule_registry):
orig_names = self.subst_rule_old_names.get(key, [])
# If no orig_names are found, then this particular
# subst rule was never referenced, and so it's fine
# to leave out.
if not orig_names:
continue
new_name = min(orig_names)
if new_name in used_names:
new_name = self.make_unique_var_name(new_name)
renames[name] = new_name
used_names.add(new_name)
result[new_name] = SubstitutionRule(
name=new_name,
arguments=args,
expression=body)
# {{{ perform renames on new substitutions
subst_renamer = SubstitutionRuleRenamer(renames)
renamed_result = {}
for name, rule in six.iteritems(result):
renamed_result[name] = rule.copy(
expression=subst_renamer(rule.expression))
# }}}
return renamed_result, renames
def _get_new_substitutions_and_renames(self):
"""This makes a new dictionary of substitutions from the ones
encountered in mapping all the encountered expressions.
It tries hard to keep substitution names the same--i.e.
if all derivative versions of a substitution rule ended
up with the same mapped version, then this version should
retain the name that the substitution rule had previously.
Unfortunately, this can't be done in a single pass, and so
the routine returns an additional dictionary *subst_renames*
of renamings to be performed on the processed expressions.
The returned substitutions already have the rename applied
to them.
:returns: (new_substitutions, subst_renames)
"""
from loopy.kernel.data import SubstitutionRule
orig_name_histogram = {}
for key, (name, orig_name) in six.iteritems(self.subst_rule_registry):
if self.subst_rule_use_count.get(key, 0):
orig_name_histogram[orig_name] = \
orig_name_histogram.get(orig_name, 0) + 1
result = {}
renames = {}
for key, (name, orig_name) in six.iteritems(self.subst_rule_registry):
args, body = key
if self.subst_rule_use_count.get(key, 0):
if orig_name_histogram[orig_name] == 1 and name != orig_name:
renames[name] = orig_name
name = orig_name
result[name] = SubstitutionRule(name=name,
arguments=args,
expression=body)
# {{{ perform renames on new substitutions
subst_renamer = SubstitutionRuleRenamer(renames)
renamed_result = {}
for name, rule in six.iteritems(result):
renamed_result[name] = rule.copy(
expression=subst_renamer(rule.expression))
# }}}
return renamed_result, renames
def extract_subst(kernel, subst_name, template, parameters=()):
"""
:arg subst_name: The name of the substitution rule to be created.
:arg template: Unification template expression.
:arg parameters: An iterable of parameters used in
*template*, or a comma-separated string of the same.
All targeted subexpressions must match ('unify with') *template*
The template may contain '*' wildcards that will have to match exactly across all
unifications.
"""
if isinstance(template, str):
from pymbolic import parse
template = parse(template)
if isinstance(parameters, str):
parameters = tuple(s.strip() for s in parameters.split(","))
var_name_gen = kernel.get_var_name_generator()
# {{{ replace any wildcards in template with new variables
def get_unique_var_name():
based_on = subst_name + "_wc"
result = var_name_gen(based_on)
return result
from loopy.symbolic import WildcardToUniqueVariableMapper
wc_map = WildcardToUniqueVariableMapper(get_unique_var_name)
template = wc_map(template)
# }}}
# {{{ gather up expressions
expr_descriptors = []
from loopy.symbolic import UnidirectionalUnifier
unif = UnidirectionalUnifier(lhs_mapping_candidates=set(parameters))
def gather_exprs(expr, mapper):
urecs = unif(template, expr)
if urecs:
if len(urecs) > 1:
raise RuntimeError(
"ambiguous unification of '%s' with template '%s'" %
(expr, template))
urec, = urecs
expr_descriptors.append(
ExprDescriptor(insn=insn,
expr=expr,
unif_var_dict=dict(
(lhs.name, rhs)
for lhs, rhs in urec.equations)))
else:
mapper.fallback_mapper(expr)
# can't nest, don't recurse
from loopy.symbolic import (CallbackMapper, WalkMapper, IdentityMapper)
dfmapper = CallbackMapper(gather_exprs, WalkMapper())
for insn in kernel.instructions:
dfmapper(insn.assignees)
dfmapper(insn.expression)
for sr in six.itervalues(kernel.substitutions):
dfmapper(sr.expression)
# }}}
if not expr_descriptors:
raise RuntimeError("no expressions matching '%s'" % template)
# {{{ substitute rule into instructions
def replace_exprs(expr, mapper):
found = False
for exprd in expr_descriptors:
if expr is exprd.expr:
found = True
break
if not found:
return mapper.fallback_mapper(expr)
args = [exprd.unif_var_dict[arg_name] for arg_name in parameters]
result = var(subst_name)
if args:
result = result(*args)
return result
# can't nest, don't recurse
cbmapper = CallbackMapper(replace_exprs, IdentityMapper())
new_insns = []
for insn in kernel.instructions:
new_insns.append(insn.with_transformed_expressions(cbmapper))
from loopy.kernel.data import SubstitutionRule
new_substs = {
subst_name:
SubstitutionRule(
name=subst_name,
arguments=tuple(parameters),
expression=template,
)
}
for subst in six.itervalues(kernel.substitutions):
new_substs[subst.name] = subst.copy(
expression=cbmapper(subst.expression))
# }}}
return kernel.copy(instructions=new_insns, substitutions=new_substs)
def assignment_to_subst(kernel,
lhs_name,
extra_arguments=(),
within=None,
force_retain_argument=False):
"""Extract an assignment (to a temporary variable or an argument)
as a :ref:`substitution-rule`. The temporary may be an array, in
which case the array indices will become arguments to the substitution
rule.
:arg within: a stack match as understood by
:func:`loopy.match.parse_stack_match`.
:arg force_retain_argument: If True and if *lhs_name* is an argument, it is
kept even if it is no longer referenced.
This operation will change all usage sites
of *lhs_name* matched by *within*. If there
are further usage sites of *lhs_name*, then
the original assignment to *lhs_name* as well
as the temporary variable is left in place.
"""
if isinstance(extra_arguments, str):
extra_arguments = tuple(s.strip() for s in extra_arguments.split(","))
# {{{ establish the relevant definition of lhs_name for each usage site
dep_kernel = expand_subst(kernel)
from loopy.kernel.creation import apply_single_writer_depencency_heuristic
dep_kernel = apply_single_writer_depencency_heuristic(dep_kernel)
id_to_insn = dep_kernel.id_to_insn
def get_relevant_definition_insn_id(usage_insn_id):
insn = id_to_insn[usage_insn_id]
def_id = set()
for dep_id in insn.depends_on:
dep_insn = id_to_insn[dep_id]
if lhs_name in dep_insn.write_dependency_names():
if lhs_name in dep_insn.read_dependency_names():
raise LoopyError(
"instruction '%s' both reads *and* "
"writes '%s'--cannot transcribe to substitution "
"rule" % (dep_id, lhs_name))
def_id.add(dep_id)
else:
rec_result = get_relevant_definition_insn_id(dep_id)
if rec_result is not None:
def_id.add(rec_result)
if len(def_id) > 1:
raise LoopyError(
"more than one write to '%s' found in "
"depdendencies of '%s'--definition cannot be resolved "
"(writer instructions ids: %s)" %
(lhs_name, usage_insn_id, ", ".join(def_id)))
if not def_id:
return None
else:
def_id, = def_id
return def_id
usage_to_definition = {}
for insn in dep_kernel.instructions:
if lhs_name not in insn.read_dependency_names():
continue
def_id = get_relevant_definition_insn_id(insn.id)
if def_id is None:
raise LoopyError("no write to '%s' found in dependency tree "
"of '%s'--definition cannot be resolved" %
(lhs_name, insn.id))
usage_to_definition[insn.id] = def_id
definition_insn_ids = set()
for insn in kernel.instructions:
if lhs_name in insn.write_dependency_names():
definition_insn_ids.add(insn.id)
# }}}
if not definition_insn_ids:
raise LoopyError("no assignments to variable '%s' found" % lhs_name)
from loopy.match import parse_stack_match
within = parse_stack_match(within)
rule_mapping_context = SubstitutionRuleMappingContext(
kernel.substitutions, kernel.get_var_name_generator())
tts = AssignmentToSubstChanger(rule_mapping_context, lhs_name,
definition_insn_ids, usage_to_definition,
extra_arguments, within)
kernel = rule_mapping_context.finish_kernel(tts.map_kernel(kernel))
from loopy.kernel.data import SubstitutionRule
# {{{ create new substitution rules
new_substs = kernel.substitutions.copy()
for def_id, subst_name in six.iteritems(
tts.definition_insn_id_to_subst_name):
def_insn = kernel.id_to_insn[def_id]
from loopy.kernel.data import Assignment
assert isinstance(def_insn, Assignment)
from pymbolic.primitives import Variable, Subscript
if isinstance(def_insn.assignee, Subscript):
indices = def_insn.assignee.index_tuple
elif isinstance(def_insn.assignee, Variable):
indices = ()
else:
raise LoopyError("Unrecognized LHS type: %s" %
type(def_insn.assignee).__name__)
arguments = []
for i in indices:
if not isinstance(i, Variable):
raise LoopyError("In defining instruction '%s': "
"asignee index '%s' is not a plain variable. "
"Perhaps use loopy.affine_map_inames() "
"to perform substitution." % (def_id, i))
arguments.append(i.name)
new_substs[subst_name] = SubstitutionRule(
name=subst_name,
arguments=tuple(arguments) + extra_arguments,
expression=def_insn.expression)
# }}}
# {{{ delete temporary variable if possible
# (copied below if modified)
new_temp_vars = kernel.temporary_variables
new_args = kernel.args
if lhs_name in kernel.temporary_variables:
if not any(six.itervalues(tts.saw_unmatched_usage_sites)):
# All usage sites matched--they're now substitution rules.
# We can get rid of the variable.
new_temp_vars = new_temp_vars.copy()
del new_temp_vars[lhs_name]
if lhs_name in kernel.arg_dict and not force_retain_argument:
if not any(six.itervalues(tts.saw_unmatched_usage_sites)):
# All usage sites matched--they're now substitution rules.
# We can get rid of the argument
new_args = new_args[:]
for i in range(len(new_args)):
if new_args[i].name == lhs_name:
del new_args[i]
break
# }}}
import loopy as lp
kernel = lp.remove_instructions(
kernel,
set(insn_id for insn_id, still_used in six.iteritems(
tts.saw_unmatched_usage_sites) if not still_used))
return kernel.copy(
substitutions=new_substs,
temporary_variables=new_temp_vars,
args=new_args,
)
def extract_subst(kernel, subst_name, template, parameters=(), within=None):
"""
:arg subst_name: The name of the substitution rule to be created.
:arg template: Unification template expression.
:arg parameters: An iterable of parameters used in
*template*, or a comma-separated string of the same.
:arg within: An instance of :class:`loopy.match.MatchExpressionBase` or
:class:`str` as understood by :func:`loopy.match.parse_match`.
All targeted subexpressions must match ('unify with') *template*
The template may contain '*' wildcards that will have to match exactly across all
unifications.
"""
if isinstance(kernel, TranslationUnit):
kernel_names = [
i for i, clbl in kernel.callables_table.items()
if isinstance(clbl, CallableKernel)
]
if len(kernel_names) != 1:
raise LoopyError()
return kernel.with_kernel(
extract_subst(kernel[kernel_names[0]], subst_name, template,
parameters))
if isinstance(template, str):
from pymbolic import parse
template = parse(template)
if isinstance(parameters, str):
parameters = tuple(s.strip() for s in parameters.split(","))
from loopy.match import parse_match
within = parse_match(within)
var_name_gen = kernel.get_var_name_generator()
# {{{ replace any wildcards in template with new variables
def get_unique_var_name():
based_on = subst_name + "_wc"
result = var_name_gen(based_on)
return result
from loopy.symbolic import WildcardToUniqueVariableMapper
wc_map = WildcardToUniqueVariableMapper(get_unique_var_name)
template = wc_map(template)
# }}}
# {{{ gather up expressions
expr_descriptors = []
from loopy.symbolic import UnidirectionalUnifier
unif = UnidirectionalUnifier(lhs_mapping_candidates=set(parameters))
def gather_exprs(expr, mapper):
urecs = unif(template, expr)
if urecs:
if len(urecs) > 1:
raise RuntimeError(
"ambiguous unification of '%s' with template '%s'" %
(expr, template))
urec, = urecs
expr_descriptors.append(
ExprDescriptor(insn=insn,
expr=expr,
unif_var_dict={
lhs.name: rhs
for lhs, rhs in urec.equations
}))
else:
mapper.fallback_mapper(expr)
# can't nest, don't recurse
from loopy.symbolic import (CallbackMapper, WalkMapper, IdentityMapper)
dfmapper = CallbackMapper(gather_exprs, WalkMapper())
from loopy.kernel.instruction import MultiAssignmentBase
for insn in kernel.instructions:
if isinstance(insn, MultiAssignmentBase) and within(kernel, insn):
dfmapper(insn.assignees)
dfmapper(insn.expression)
for sr in kernel.substitutions.values():
dfmapper(sr.expression)
# }}}
if not expr_descriptors:
raise RuntimeError("no expressions matching '%s'" % template)
# {{{ substitute rule into instructions
def replace_exprs(expr, mapper):
found = False
for exprd in expr_descriptors:
if expr is exprd.expr:
found = True
break
if not found:
return mapper.fallback_mapper(expr)
args = [exprd.unif_var_dict[arg_name] for arg_name in parameters]
result = var(subst_name)
if args:
result = result(*args)
return result
# can't nest, don't recurse
cbmapper = CallbackMapper(replace_exprs, IdentityMapper())
new_insns = []
def transform_assignee(expr):
# Assignment LHS's cannot be subst rules. Treat them
# specially.
import pymbolic.primitives as prim
if isinstance(expr, tuple):
return tuple(transform_assignee(expr_i) for expr_i in expr)
elif isinstance(expr, prim.Subscript):
return type(expr)(expr.aggregate, cbmapper(expr.index))
elif isinstance(expr, prim.Variable):
return expr
else:
raise ValueError("assignment LHS not understood")
for insn in kernel.instructions:
if within(kernel, insn):
new_insns.append(
insn.with_transformed_expressions(
cbmapper, assignee_f=transform_assignee))
else:
new_insns.append(insn)
from loopy.kernel.data import SubstitutionRule
new_substs = {
subst_name:
SubstitutionRule(
name=subst_name,
arguments=tuple(parameters),
expression=template,
)
}
for subst in kernel.substitutions.values():
new_substs[subst.name] = subst.copy(
expression=cbmapper(subst.expression))
# }}}
return kernel.copy(instructions=new_insns, substitutions=new_substs)
