示例#1
0
文件: iname.py 项目: navjotk/loopy
def tag_inames(kernel, iname_to_tag, force=False, ignore_nonexistent=False):
    from loopy.kernel.data import parse_tag

    iname_to_tag = dict((iname, parse_tag(tag))
            for iname, tag in six.iteritems(iname_to_tag))

    from loopy.kernel.data import (ParallelTag, AutoLocalIndexTagBase,
            ForceSequentialTag)

    new_iname_to_tag = kernel.iname_to_tag.copy()
    for iname, new_tag in six.iteritems(iname_to_tag):
        if iname not in kernel.all_inames():
            if ignore_nonexistent:
                continue
            else:
                raise LoopyError("iname '%s' does not exist" % iname)

        old_tag = kernel.iname_to_tag.get(iname)

        retag_ok = False

        if isinstance(old_tag, (AutoLocalIndexTagBase, ForceSequentialTag)):
            retag_ok = True

        if not retag_ok and old_tag is not None and new_tag is None:
            raise ValueError("cannot untag iname '%s'" % iname)

        if iname not in kernel.all_inames():
            raise ValueError("cannot tag '%s'--not known" % iname)

        if isinstance(new_tag, ParallelTag) \
                and isinstance(old_tag, ForceSequentialTag):
            raise ValueError("cannot tag '%s' as parallel--"
                    "iname requires sequential execution" % iname)

        if isinstance(new_tag, ForceSequentialTag) \
                and isinstance(old_tag, ParallelTag):
            raise ValueError("'%s' is already tagged as parallel, "
                    "but is now prohibited from being parallel "
                    "(likely because of participation in a precompute or "
                    "a reduction)" % iname)

        if (not retag_ok) and (not force) \
                and old_tag is not None and (old_tag != new_tag):
            raise LoopyError("'%s' is already tagged '%s'--cannot retag"
                    % (iname, old_tag))

        new_iname_to_tag[iname] = new_tag

    return kernel.copy(iname_to_tag=new_iname_to_tag)
示例#2
0
def precompute(
        kernel,
        subst_use,
        sweep_inames=[],
        within=None,
        storage_axes=None,
        temporary_name=None,
        precompute_inames=None,
        precompute_outer_inames=None,
        storage_axis_to_tag={},

        # "None" is a valid value here, distinct from the default.
        default_tag=_not_provided,
        dtype=None,
        fetch_bounding_box=False,
        temporary_address_space=None,
        compute_insn_id=None,
        **kwargs):
    """Precompute the expression described in the substitution rule determined by
    *subst_use* and store it in a temporary array. A precomputation needs two
    things to operate, a list of *sweep_inames* (order irrelevant) and an
    ordered list of *storage_axes* (whose order will describe the axis ordering
    of the temporary array).

    :arg subst_use: Describes what to prefetch.

        The following objects may be given for *subst_use*:

        * The name of the substitution rule.

        * The tagged name ("name$tag") of the substitution rule.

        * A list of invocations of the substitution rule.
          This list of invocations, when swept across *sweep_inames*, then serves
          to define the footprint of the precomputation.

          Invocations may be tagged ("name$tag") to filter out a subset of the
          usage sites of the substitution rule. (Namely those usage sites that
          use the same tagged name.)

          Invocations may be given as a string or as a
          :class:`pymbolic.primitives.Expression` object.

          If only one invocation is to be given, then the only entry of the list
          may be given directly.

    If the list of invocations generating the footprint is not given,
    all (tag-matching, if desired) usage sites of the substitution rule
    are used to determine the footprint.

    The following cases can arise for each sweep axis:

    * The axis is an iname that occurs within arguments specified at
      usage sites of the substitution rule. This case is assumed covered
      by the storage axes provided for the argument.

    * The axis is an iname that occurs within the *value* of the rule, but not
      within its arguments. A new, dedicated storage axis is allocated for
      such an axis.

    :arg sweep_inames: A :class:`list` of inames to be swept.
        May also equivalently be a comma-separated string.
    :arg within: a stack match as understood by
        :func:`loopy.match.parse_stack_match`.
    :arg storage_axes: A :class:`list` of inames and/or rule argument
        names/indices to be used as storage axes.
        May also equivalently be a comma-separated string.
    :arg temporary_name:
        The temporary variable name to use for storing the precomputed data.
        If it does not exist, it will be created. If it does exist, its properties
        (such as size, type) are checked (and updated, if possible) to match
        its use.
    :arg precompute_inames:
        A tuple of inames to be used to carry out the precomputation.
        If the specified inames do not already exist, they will be
        created. If they do already exist, their loop domain is verified
        against the one required for this precomputation. This tuple may
        be shorter than the (provided or automatically found) *storage_axes*
        tuple, in which case names will be automatically created.
        May also equivalently be a comma-separated string.

    :arg precompute_outer_inames: A :class:`frozenset` of inames within which
        the compute instruction is nested. If *None*, make an educated guess.
        May also be specified as a comma-separated string.

    :arg default_tag: The :ref:`iname tag <iname-tags>` to be applied to the
        inames created to perform the precomputation. The current default will
        make them local axes and automatically split them to fit the work
        group size, but this default will disappear in favor of simply leaving them
        untagged in 2019. For 2018, a warning will be issued if no *default_tag* is
        specified.

    :arg compute_insn_id: The ID of the instruction generated to perform the
        precomputation.

    If `storage_axes` is not specified, it defaults to the arrangement
    `<direct sweep axes><arguments>` with the direct sweep axes being the
    slower-varying indices.

    Trivial storage axes (i.e. axes of length 1 with respect to the sweep) are
    eliminated.
    """

    # {{{ unify temporary_address_space / temporary_scope

    temporary_scope = kwargs.pop("temporary_scope", None)

    from loopy.kernel.data import AddressSpace
    if temporary_scope is not None:
        from warnings import warn
        warn(
            "temporary_scope is deprecated. Use temporary_address_space instead",
            DeprecationWarning,
            stacklevel=2)

        if temporary_address_space is not None:
            raise LoopyError(
                "may not specify both temporary_address_space and "
                "temporary_scope")

        temporary_address_space = temporary_scope

    del temporary_scope

    # }}}

    if kwargs:
        raise TypeError("unrecognized keyword arguments: %s" %
                        ", ".join(kwargs.keys()))

    # {{{ check, standardize arguments

    if isinstance(sweep_inames, str):
        sweep_inames = [iname.strip() for iname in sweep_inames.split(",")]

    for iname in sweep_inames:
        if iname not in kernel.all_inames():
            raise RuntimeError("sweep iname '%s' is not a known iname" % iname)

    sweep_inames = list(sweep_inames)
    sweep_inames_set = frozenset(sweep_inames)

    if isinstance(storage_axes, str):
        storage_axes = [ax.strip() for ax in storage_axes.split(",")]

    if isinstance(precompute_inames, str):
        precompute_inames = [
            iname.strip() for iname in precompute_inames.split(",")
        ]

    if isinstance(precompute_outer_inames, str):
        precompute_outer_inames = frozenset(
            iname.strip() for iname in precompute_outer_inames.split(","))

    if isinstance(subst_use, str):
        subst_use = [subst_use]

    footprint_generators = None

    subst_name = None
    subst_tag = None

    from pymbolic.primitives import Variable, Call
    from loopy.symbolic import parse, TaggedVariable

    for use in subst_use:
        if isinstance(use, str):
            use = parse(use)

        if isinstance(use, Call):
            if footprint_generators is None:
                footprint_generators = []

            footprint_generators.append(use)
            subst_name_as_expr = use.function
        else:
            subst_name_as_expr = use

        if isinstance(subst_name_as_expr, TaggedVariable):
            new_subst_name = subst_name_as_expr.name
            new_subst_tag = subst_name_as_expr.tag
        elif isinstance(subst_name_as_expr, Variable):
            new_subst_name = subst_name_as_expr.name
            new_subst_tag = None
        else:
            raise ValueError("unexpected type of subst_name")

        if (subst_name, subst_tag) == (None, None):
            subst_name, subst_tag = new_subst_name, new_subst_tag
        else:
            if (subst_name, subst_tag) != (new_subst_name, new_subst_tag):
                raise ValueError("not all uses in subst_use agree "
                                 "on rule name and tag")

    from loopy.match import parse_stack_match
    within = parse_stack_match(within)

    try:
        subst = kernel.substitutions[subst_name]
    except KeyError:
        raise LoopyError("substitution rule '%s' not found" % subst_name)

    c_subst_name = subst_name.replace(".", "_")

    # {{{ handle default_tag

    from loopy.transform.data import _not_provided \
            as transform_data_not_provided

    if default_tag is _not_provided or default_tag is transform_data_not_provided:
        # no need to warn for scalar precomputes
        if sweep_inames:
            from warnings import warn
            warn(
                "Not specifying default_tag is deprecated, and default_tag "
                "will become mandatory in 2019.x. "
                "Pass 'default_tag=\"l.auto\" to match the current default, "
                "or Pass 'default_tag=None to leave the loops untagged, which "
                "is the recommended behavior.",
                DeprecationWarning,
                stacklevel=(

                    # In this case, we came here through add_prefetch. Increase
                    # the stacklevel.
                    3 if default_tag is transform_data_not_provided else 2))

        default_tag = "l.auto"

    from loopy.kernel.data import parse_tag
    default_tag = parse_tag(default_tag)

    # }}}

    # }}}

    # {{{ process invocations in footprint generators, start access_descriptors

    if footprint_generators:
        from pymbolic.primitives import Variable, Call

        access_descriptors = []

        for fpg in footprint_generators:
            if isinstance(fpg, Variable):
                args = ()
            elif isinstance(fpg, Call):
                args = fpg.parameters
            else:
                raise ValueError("footprint generator must "
                                 "be substitution rule invocation")

            access_descriptors.append(
                RuleAccessDescriptor(identifier=access_descriptor_id(
                    args, None),
                                     args=args))

    # }}}

    # {{{ gather up invocations in kernel code, finish access_descriptors

    if not footprint_generators:
        rule_mapping_context = SubstitutionRuleMappingContext(
            kernel.substitutions, kernel.get_var_name_generator())
        invg = RuleInvocationGatherer(rule_mapping_context, kernel, subst_name,
                                      subst_tag, within)
        del rule_mapping_context

        import loopy as lp
        for insn in kernel.instructions:
            if isinstance(insn, lp.MultiAssignmentBase):
                for assignee in insn.assignees:
                    invg(assignee, kernel, insn)
                invg(insn.expression, kernel, insn)

        access_descriptors = invg.access_descriptors
        if not access_descriptors:
            raise RuntimeError("no invocations of '%s' found" % subst_name)

    # }}}

    # {{{ find inames used in arguments

    expanding_usage_arg_deps = set()

    for accdesc in access_descriptors:
        for arg in accdesc.args:
            expanding_usage_arg_deps.update(
                get_dependencies(arg) & kernel.all_inames())

    # }}}

    var_name_gen = kernel.get_var_name_generator()

    # {{{ use given / find new storage_axes

    # extra axes made necessary because they don't occur in the arguments
    extra_storage_axes = set(sweep_inames_set - expanding_usage_arg_deps)

    from loopy.symbolic import SubstitutionRuleExpander
    submap = SubstitutionRuleExpander(kernel.substitutions)

    value_inames = (get_dependencies(submap(subst.expression)) -
                    frozenset(subst.arguments)) & kernel.all_inames()
    if value_inames - expanding_usage_arg_deps < extra_storage_axes:
        raise RuntimeError("unreferenced sweep inames specified: " +
                           ", ".join(extra_storage_axes - value_inames -
                                     expanding_usage_arg_deps))

    new_iname_to_tag = {}

    if storage_axes is None:
        storage_axes = []

        # Add sweep_inames (in given--rather than arbitrary--order) to
        # storage_axes *if* they are part of extra_storage_axes.
        for iname in sweep_inames:
            if iname in extra_storage_axes:
                extra_storage_axes.remove(iname)
                storage_axes.append(iname)

        if extra_storage_axes:
            if (precompute_inames is not None
                    and len(storage_axes) < len(precompute_inames)):
                raise LoopyError(
                    "must specify a sufficient number of "
                    "storage_axes to uniquely determine the meaning "
                    "of the given precompute_inames. (%d storage_axes "
                    "needed)" % len(precompute_inames))
            storage_axes.extend(sorted(extra_storage_axes))

        storage_axes.extend(range(len(subst.arguments)))

    del extra_storage_axes

    prior_storage_axis_name_dict = {}

    storage_axis_names = []
    storage_axis_sources = []  # number for arg#, or iname

    # {{{ check for pre-existing precompute_inames

    if precompute_inames is not None:
        preexisting_precompute_inames = (set(precompute_inames)
                                         & kernel.all_inames())
    else:
        preexisting_precompute_inames = set()

    # }}}

    for i, saxis in enumerate(storage_axes):
        tag_lookup_saxis = saxis

        if saxis in subst.arguments:
            saxis = subst.arguments.index(saxis)

        storage_axis_sources.append(saxis)

        if isinstance(saxis, int):
            # argument index
            name = old_name = subst.arguments[saxis]
        else:
            old_name = saxis
            name = "%s_%s" % (c_subst_name, old_name)

        if (precompute_inames is not None and i < len(precompute_inames)
                and precompute_inames[i]):
            name = precompute_inames[i]
            tag_lookup_saxis = name
            if (name not in preexisting_precompute_inames
                    and var_name_gen.is_name_conflicting(name)):
                raise RuntimeError("new storage axis name '%s' "
                                   "conflicts with existing name" % name)
        else:
            name = var_name_gen(name)

        storage_axis_names.append(name)
        if name not in preexisting_precompute_inames:
            new_iname_to_tag[name] = storage_axis_to_tag.get(
                tag_lookup_saxis, default_tag)

        prior_storage_axis_name_dict[name] = old_name

    del storage_axis_to_tag
    del storage_axes
    del precompute_inames

    # }}}

    # {{{ fill out access_descriptors[...].storage_axis_exprs

    access_descriptors = [
        accdesc.copy(storage_axis_exprs=storage_axis_exprs(
            storage_axis_sources, accdesc.args))
        for accdesc in access_descriptors
    ]

    # }}}

    expanding_inames = sweep_inames_set | frozenset(expanding_usage_arg_deps)
    assert expanding_inames <= kernel.all_inames()

    if storage_axis_names:
        # {{{ find domain to be changed

        change_inames = expanding_inames | preexisting_precompute_inames

        from loopy.kernel.tools import DomainChanger
        domch = DomainChanger(kernel, change_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 sweep_inames_set:
                if kernel.get_home_domain_index(
                        iname) != domch.leaf_domain_index:
                    raise RuntimeError(
                        "sweep iname '%s' is not 'at home' in the "
                        "sweep's leaf domain" % iname)

        # }}}

        abm = ArrayToBufferMap(kernel, domch.domain, sweep_inames,
                               access_descriptors, len(storage_axis_names))

        non1_storage_axis_names = []
        for i, saxis in enumerate(storage_axis_names):
            if abm.non1_storage_axis_flags[i]:
                non1_storage_axis_names.append(saxis)
            else:
                del new_iname_to_tag[saxis]

                if saxis in preexisting_precompute_inames:
                    raise LoopyError(
                        "precompute axis %d (1-based) was "
                        "eliminated as "
                        "having length 1 but also mapped to existing "
                        "iname '%s'" % (i + 1, saxis))

        mod_domain = domch.domain

        # {{{ modify the domain, taking into account preexisting inames

        # inames may already exist in mod_domain, add them primed to start
        primed_non1_saxis_names = [
            iname + "'" for iname in non1_storage_axis_names
        ]

        mod_domain = abm.augment_domain_with_sweep(
            domch.domain,
            primed_non1_saxis_names,
            boxify_sweep=fetch_bounding_box)

        check_domain = mod_domain

        for i, saxis in enumerate(non1_storage_axis_names):
            var_dict = mod_domain.get_var_dict(isl.dim_type.set)

            if saxis in preexisting_precompute_inames:
                # add equality constraint between existing and new variable

                dt, dim_idx = var_dict[saxis]
                saxis_aff = isl.Aff.var_on_domain(mod_domain.space, dt,
                                                  dim_idx)

                dt, dim_idx = var_dict[primed_non1_saxis_names[i]]
                new_var_aff = isl.Aff.var_on_domain(mod_domain.space, dt,
                                                    dim_idx)

                mod_domain = mod_domain.add_constraint(
                    isl.Constraint.equality_from_aff(new_var_aff - saxis_aff))

                # project out the new one
                mod_domain = mod_domain.project_out(dt, dim_idx, 1)

            else:
                # remove the prime from the new variable
                dt, dim_idx = var_dict[primed_non1_saxis_names[i]]
                mod_domain = mod_domain.set_dim_name(dt, dim_idx, saxis)

        def add_assumptions(d):
            assumption_non_param = isl.BasicSet.from_params(kernel.assumptions)
            assumptions, domain = isl.align_two(assumption_non_param, d)
            return assumptions & domain

        # {{{ check that we got the desired domain

        check_domain = add_assumptions(
            check_domain.project_out_except(primed_non1_saxis_names,
                                            [isl.dim_type.set]))

        mod_check_domain = add_assumptions(mod_domain)

        # re-add the prime from the new variable
        var_dict = mod_check_domain.get_var_dict(isl.dim_type.set)

        for saxis in non1_storage_axis_names:
            dt, dim_idx = var_dict[saxis]
            mod_check_domain = mod_check_domain.set_dim_name(
                dt, dim_idx, saxis + "'")

        mod_check_domain = mod_check_domain.project_out_except(
            primed_non1_saxis_names, [isl.dim_type.set])

        mod_check_domain, check_domain = isl.align_two(mod_check_domain,
                                                       check_domain)

        # The modified domain can't get bigger by adding constraints
        assert mod_check_domain <= check_domain

        if not check_domain <= mod_check_domain:
            print(check_domain)
            print(mod_check_domain)
            raise LoopyError("domain of preexisting inames does not match "
                             "domain needed for precompute")

        # }}}

        # {{{ check that we didn't shrink the original domain

        # project out the new names from the modified domain
        orig_domain_inames = list(domch.domain.get_var_dict(isl.dim_type.set))
        mod_check_domain = add_assumptions(
            mod_domain.project_out_except(orig_domain_inames,
                                          [isl.dim_type.set]))

        check_domain = add_assumptions(domch.domain)

        mod_check_domain, check_domain = isl.align_two(mod_check_domain,
                                                       check_domain)

        # The modified domain can't get bigger by adding constraints
        assert mod_check_domain <= check_domain

        if not check_domain <= mod_check_domain:
            print(check_domain)
            print(mod_check_domain)
            raise LoopyError(
                "original domain got shrunk by applying the precompute")

        # }}}

        # }}}

        new_kernel_domains = domch.get_domains_with(mod_domain)

    else:
        # leave kernel domains unchanged
        new_kernel_domains = kernel.domains

        non1_storage_axis_names = []
        abm = NoOpArrayToBufferMap()

    kernel = kernel.copy(domains=new_kernel_domains)

    # {{{ set up compute insn

    if temporary_name is None:
        temporary_name = var_name_gen(based_on=c_subst_name)

    assignee = var(temporary_name)

    if non1_storage_axis_names:
        assignee = assignee[tuple(
            var(iname) for iname in non1_storage_axis_names)]

    # {{{ process substitutions on compute instruction

    storage_axis_subst_dict = {}

    for arg_name, bi in zip(storage_axis_names, abm.storage_base_indices):
        if arg_name in non1_storage_axis_names:
            arg = var(arg_name)
        else:
            arg = 0

        storage_axis_subst_dict[prior_storage_axis_name_dict.get(
            arg_name, arg_name)] = arg + bi

    rule_mapping_context = SubstitutionRuleMappingContext(
        kernel.substitutions, kernel.get_var_name_generator())

    from loopy.match import parse_stack_match
    expr_subst_map = RuleAwareSubstitutionMapper(
        rule_mapping_context,
        make_subst_func(storage_axis_subst_dict),
        within=parse_stack_match(None))

    compute_expression = expr_subst_map(subst.expression, kernel, None)

    # }}}

    from loopy.kernel.data import Assignment
    if compute_insn_id is None:
        compute_insn_id = kernel.make_unique_instruction_id(
            based_on=c_subst_name)

    compute_insn = Assignment(
        id=compute_insn_id,
        assignee=assignee,
        expression=compute_expression,
        # within_inames determined below
    )
    compute_dep_id = compute_insn_id
    added_compute_insns = [compute_insn]

    if temporary_address_space == AddressSpace.GLOBAL:
        barrier_insn_id = kernel.make_unique_instruction_id(
            based_on=c_subst_name + "_barrier")
        from loopy.kernel.instruction import BarrierInstruction
        barrier_insn = BarrierInstruction(id=barrier_insn_id,
                                          depends_on=frozenset(
                                              [compute_insn_id]),
                                          synchronization_kind="global",
                                          mem_kind="global")
        compute_dep_id = barrier_insn_id

        added_compute_insns.append(barrier_insn)

    # }}}

    # {{{ substitute rule into expressions in kernel (if within footprint)

    from loopy.symbolic import SubstitutionRuleExpander
    expander = SubstitutionRuleExpander(kernel.substitutions)

    invr = RuleInvocationReplacer(rule_mapping_context,
                                  subst_name,
                                  subst_tag,
                                  within,
                                  access_descriptors,
                                  abm,
                                  storage_axis_names,
                                  storage_axis_sources,
                                  non1_storage_axis_names,
                                  temporary_name,
                                  compute_insn_id,
                                  compute_dep_id,
                                  compute_read_variables=get_dependencies(
                                      expander(compute_expression)))

    kernel = invr.map_kernel(kernel)
    kernel = kernel.copy(instructions=added_compute_insns +
                         kernel.instructions)
    kernel = rule_mapping_context.finish_kernel(kernel)

    # }}}

    # {{{ add dependencies to compute insn

    kernel = kernel.copy(instructions=[
        insn.copy(depends_on=frozenset(invr.compute_insn_depends_on)) if insn.
        id == compute_insn_id else insn for insn in kernel.instructions
    ])

    # }}}

    # {{{ propagate storage iname subst to dependencies of compute instructions

    from loopy.kernel.tools import find_recursive_dependencies
    compute_deps = find_recursive_dependencies(kernel,
                                               frozenset([compute_insn_id]))

    # FIXME: Need to verify that there are no outside dependencies
    # on compute_deps

    prior_storage_axis_names = frozenset(storage_axis_subst_dict)

    new_insns = []
    for insn in kernel.instructions:
        if (insn.id in compute_deps
                and insn.within_inames & prior_storage_axis_names):
            insn = (insn.with_transformed_expressions(
                lambda expr: expr_subst_map(expr, kernel, insn)).copy(
                    within_inames=frozenset(
                        storage_axis_subst_dict.get(iname, var(iname)).name
                        for iname in insn.within_inames)))

            new_insns.append(insn)
        else:
            new_insns.append(insn)

    kernel = kernel.copy(instructions=new_insns)

    # }}}

    # {{{ determine inames for compute insn

    if precompute_outer_inames is None:
        from loopy.kernel.tools import guess_iname_deps_based_on_var_use
        precompute_outer_inames = (
            frozenset(non1_storage_axis_names)
            | frozenset((expanding_usage_arg_deps | value_inames) -
                        sweep_inames_set)
            | guess_iname_deps_based_on_var_use(kernel, compute_insn))
    else:
        if not isinstance(precompute_outer_inames, frozenset):
            raise TypeError("precompute_outer_inames must be a frozenset")

        precompute_outer_inames = precompute_outer_inames \
                | frozenset(non1_storage_axis_names)

    kernel = kernel.copy(instructions=[
        insn.copy(within_inames=precompute_outer_inames) if insn.id ==
        compute_insn_id else insn for insn in kernel.instructions
    ])

    # }}}

    # {{{ set up temp variable

    import loopy as lp
    if dtype is not None:
        dtype = np.dtype(dtype)

    if temporary_address_space is None:
        temporary_address_space = lp.auto

    new_temp_shape = tuple(abm.non1_storage_shape)

    new_temporary_variables = kernel.temporary_variables.copy()
    if temporary_name not in new_temporary_variables:
        temp_var = lp.TemporaryVariable(
            name=temporary_name,
            dtype=dtype,
            base_indices=(0, ) * len(new_temp_shape),
            shape=tuple(abm.non1_storage_shape),
            address_space=temporary_address_space,
            dim_names=tuple(non1_storage_axis_names))

    else:
        temp_var = new_temporary_variables[temporary_name]

        # {{{ check and adapt existing temporary

        if temp_var.dtype is lp.auto:
            pass
        elif temp_var.dtype is not lp.auto and dtype is lp.auto:
            dtype = temp_var.dtype
        elif temp_var.dtype is not lp.auto and dtype is not lp.auto:
            if temp_var.dtype != dtype:
                raise LoopyError("Existing and new dtype of temporary '%s' "
                                 "do not match (existing: %s, new: %s)" %
                                 (temporary_name, temp_var.dtype, dtype))

        temp_var = temp_var.copy(dtype=dtype)

        if len(temp_var.shape) != len(new_temp_shape):
            raise LoopyError(
                "Existing and new temporary '%s' do not "
                "have matching number of dimensions ('%d' vs. '%d') " %
                (temporary_name, len(temp_var.shape), len(new_temp_shape)))

        if temp_var.base_indices != (0, ) * len(new_temp_shape):
            raise LoopyError(
                "Existing and new temporary '%s' do not "
                "have matching number of dimensions ('%d' vs. '%d') " %
                (temporary_name, len(temp_var.shape), len(new_temp_shape)))

        new_temp_shape = tuple(
            max(i, ex_i) for i, ex_i in zip(new_temp_shape, temp_var.shape))

        temp_var = temp_var.copy(shape=new_temp_shape)

        if temporary_address_space == temp_var.address_space:
            pass
        elif temporary_address_space is lp.auto:
            temporary_address_space = temp_var.address_space
        elif temp_var.address_space is lp.auto:
            pass
        else:
            raise LoopyError("Existing and new temporary '%s' do not "
                             "have matching scopes (existing: %s, new: %s)" %
                             (temporary_name,
                              AddressSpace.stringify(temp_var.address_space),
                              AddressSpace.stringify(temporary_address_space)))

        temp_var = temp_var.copy(address_space=temporary_address_space)

        # }}}

    new_temporary_variables[temporary_name] = temp_var

    kernel = kernel.copy(temporary_variables=new_temporary_variables)

    # }}}

    from loopy import tag_inames
    kernel = tag_inames(kernel, new_iname_to_tag)

    from loopy.kernel.data import AutoFitLocalIndexTag, filter_iname_tags_by_type

    if filter_iname_tags_by_type(new_iname_to_tag.values(),
                                 AutoFitLocalIndexTag):
        from loopy.kernel.tools import assign_automatic_axes
        kernel = assign_automatic_axes(kernel)

    return kernel
示例#3
0
def precompute(kernel, subst_use, sweep_inames=[], within=None,
        storage_axes=None, temporary_name=None, precompute_inames=None,
        storage_axis_to_tag={}, default_tag="l.auto", dtype=None,
        fetch_bounding_box=False, temporary_is_local=None,
        compute_insn_id=None):
    """Precompute the expression described in the substitution rule determined by
    *subst_use* and store it in a temporary array. A precomputation needs two
    things to operate, a list of *sweep_inames* (order irrelevant) and an
    ordered list of *storage_axes* (whose order will describe the axis ordering
    of the temporary array).

    :arg subst_use: Describes what to prefetch.

    The following objects may be given for *subst_use*:

    * The name of the substitution rule.

    * The tagged name ("name$tag") of the substitution rule.

    * A list of invocations of the substitution rule.
      This list of invocations, when swept across *sweep_inames*, then serves
      to define the footprint of the precomputation.

      Invocations may be tagged ("name$tag") to filter out a subset of the
      usage sites of the substitution rule. (Namely those usage sites that
      use the same tagged name.)

      Invocations may be given as a string or as a
      :class:`pymbolic.primitives.Expression` object.

      If only one invocation is to be given, then the only entry of the list
      may be given directly.

    If the list of invocations generating the footprint is not given,
    all (tag-matching, if desired) usage sites of the substitution rule
    are used to determine the footprint.

    The following cases can arise for each sweep axis:

    * The axis is an iname that occurs within arguments specified at
      usage sites of the substitution rule. This case is assumed covered
      by the storage axes provided for the argument.

    * The axis is an iname that occurs within the *value* of the rule, but not
      within its arguments. A new, dedicated storage axis is allocated for
      such an axis.

    :arg sweep_inames: A :class:`list` of inames and/or rule argument
        names to be swept.
        May also equivalently be a comma-separated string.
    :arg storage_axes: A :class:`list` of inames and/or rule argument
        names/indices to be used as storage axes.
        May also equivalently be a comma-separated string.
    :arg within: a stack match as understood by
        :func:`loopy.context_matching.parse_stack_match`.
    :arg temporary_name:
        The temporary variable name to use for storing the precomputed data.
        If it does not exist, it will be created. If it does exist, its properties
        (such as size, type) are checked (and updated, if possible) to match
        its use.
    :arg precompute_inames:
        A tuple of inames to be used to carry out the precomputation.
        If the specified inames do not already exist, they will be
        created. If they do already exist, their loop domain is verified
        against the one required for this precomputation. This tuple may
        be shorter than the (provided or automatically found) *storage_axes*
        tuple, in which case names will be automatically created.
        May also equivalently be a comma-separated string.

    :arg compute_insn_id: The ID of the instruction performing the precomputation.

    If `storage_axes` is not specified, it defaults to the arrangement
    `<direct sweep axes><arguments>` with the direct sweep axes being the
    slower-varying indices.

    Trivial storage axes (i.e. axes of length 1 with respect to the sweep) are
    eliminated.
    """

    # {{{ check, standardize arguments

    if isinstance(sweep_inames, str):
        sweep_inames = [iname.strip() for iname in sweep_inames.split(",")]

    for iname in sweep_inames:
        if iname not in kernel.all_inames():
            raise RuntimeError("sweep iname '%s' is not a known iname"
                    % iname)

    sweep_inames = list(sweep_inames)
    sweep_inames_set = frozenset(sweep_inames)

    if isinstance(storage_axes, str):
        storage_axes = [ax.strip() for ax in storage_axes.split(",")]

    if isinstance(precompute_inames, str):
        precompute_inames = [iname.strip() for iname in precompute_inames.split(",")]

    if isinstance(subst_use, str):
        subst_use = [subst_use]

    footprint_generators = None

    subst_name = None
    subst_tag = None

    from pymbolic.primitives import Variable, Call
    from loopy.symbolic import parse, TaggedVariable

    for use in subst_use:
        if isinstance(use, str):
            use = parse(use)

        if isinstance(use, Call):
            if footprint_generators is None:
                footprint_generators = []

            footprint_generators.append(use)
            subst_name_as_expr = use.function
        else:
            subst_name_as_expr = use

        if isinstance(subst_name_as_expr, TaggedVariable):
            new_subst_name = subst_name_as_expr.name
            new_subst_tag = subst_name_as_expr.tag
        elif isinstance(subst_name_as_expr, Variable):
            new_subst_name = subst_name_as_expr.name
            new_subst_tag = None
        else:
            raise ValueError("unexpected type of subst_name")

        if (subst_name, subst_tag) == (None, None):
            subst_name, subst_tag = new_subst_name, new_subst_tag
        else:
            if (subst_name, subst_tag) != (new_subst_name, new_subst_tag):
                raise ValueError("not all uses in subst_use agree "
                        "on rule name and tag")

    from loopy.context_matching import parse_stack_match
    within = parse_stack_match(within)

    from loopy.kernel.data import parse_tag
    default_tag = parse_tag(default_tag)

    subst = kernel.substitutions[subst_name]
    c_subst_name = subst_name.replace(".", "_")

    # }}}

    # {{{ process invocations in footprint generators, start access_descriptors

    if footprint_generators:
        from pymbolic.primitives import Variable, Call

        access_descriptors = []

        for fpg in footprint_generators:
            if isinstance(fpg, Variable):
                args = ()
            elif isinstance(fpg, Call):
                args = fpg.parameters
            else:
                raise ValueError("footprint generator must "
                        "be substitution rule invocation")

            access_descriptors.append(
                    RuleAccessDescriptor(
                        identifier=access_descriptor_id(args, None),
                        args=args
                        ))

    # }}}

    # {{{ gather up invocations in kernel code, finish access_descriptors

    if not footprint_generators:
        rule_mapping_context = SubstitutionRuleMappingContext(
                kernel.substitutions, kernel.get_var_name_generator())
        invg = RuleInvocationGatherer(
                rule_mapping_context, kernel, subst_name, subst_tag, within)
        del rule_mapping_context

        import loopy as lp
        for insn in kernel.instructions:
            if isinstance(insn, lp.Assignment):
                invg(insn.assignee, kernel, insn)
                invg(insn.expression, kernel, insn)

        access_descriptors = invg.access_descriptors
        if not access_descriptors:
            raise RuntimeError("no invocations of '%s' found" % subst_name)

    # }}}

    # {{{ find inames used in arguments

    expanding_usage_arg_deps = set()

    for accdesc in access_descriptors:
        for arg in accdesc.args:
            expanding_usage_arg_deps.update(
                    get_dependencies(arg) & kernel.all_inames())

    # }}}

    var_name_gen = kernel.get_var_name_generator()

    # {{{ use given / find new storage_axes

    # extra axes made necessary because they don't occur in the arguments
    extra_storage_axes = set(sweep_inames_set - expanding_usage_arg_deps)

    from loopy.symbolic import SubstitutionRuleExpander
    submap = SubstitutionRuleExpander(kernel.substitutions)

    value_inames = get_dependencies(
            submap(subst.expression)
            ) & kernel.all_inames()
    if value_inames - expanding_usage_arg_deps < extra_storage_axes:
        raise RuntimeError("unreferenced sweep inames specified: "
                + ", ".join(extra_storage_axes
                    - value_inames - expanding_usage_arg_deps))

    new_iname_to_tag = {}

    if storage_axes is None:
        storage_axes = []

        # Add sweep_inames (in given--rather than arbitrary--order) to
        # storage_axes *if* they are part of extra_storage_axes.
        for iname in sweep_inames:
            if iname in extra_storage_axes:
                extra_storage_axes.remove(iname)
                storage_axes.append(iname)

        if extra_storage_axes:
            if (precompute_inames is not None
                    and len(storage_axes) < len(precompute_inames)):
                raise LoopyError("must specify a sufficient number of "
                        "storage_axes to uniquely determine the meaning "
                        "of the given precompute_inames. (%d storage_axes "
                        "needed)" % len(precompute_inames))
            storage_axes.extend(sorted(extra_storage_axes))

        storage_axes.extend(range(len(subst.arguments)))

    del extra_storage_axes

    prior_storage_axis_name_dict = {}

    storage_axis_names = []
    storage_axis_sources = []  # number for arg#, or iname

    # {{{ check for pre-existing precompute_inames

    if precompute_inames is not None:
        preexisting_precompute_inames = (
                set(precompute_inames) & kernel.all_inames())
    else:
        preexisting_precompute_inames = set()

    # }}}

    for i, saxis in enumerate(storage_axes):
        tag_lookup_saxis = saxis

        if saxis in subst.arguments:
            saxis = subst.arguments.index(saxis)

        storage_axis_sources.append(saxis)

        if isinstance(saxis, int):
            # argument index
            name = old_name = subst.arguments[saxis]
        else:
            old_name = saxis
            name = "%s_%s" % (c_subst_name, old_name)

        if (precompute_inames is not None
                and i < len(precompute_inames)
                and precompute_inames[i]):
            name = precompute_inames[i]
            tag_lookup_saxis = name
            if (name not in preexisting_precompute_inames
                    and var_name_gen.is_name_conflicting(name)):
                raise RuntimeError("new storage axis name '%s' "
                        "conflicts with existing name" % name)
        else:
            name = var_name_gen(name)

        storage_axis_names.append(name)
        if name not in preexisting_precompute_inames:
            new_iname_to_tag[name] = storage_axis_to_tag.get(
                    tag_lookup_saxis, default_tag)

        prior_storage_axis_name_dict[name] = old_name

    del storage_axis_to_tag
    del storage_axes
    del precompute_inames

    # }}}

    # {{{ fill out access_descriptors[...].storage_axis_exprs

    access_descriptors = [
            accdesc.copy(
                storage_axis_exprs=storage_axis_exprs(
                    storage_axis_sources, accdesc.args))
            for accdesc in access_descriptors]

    # }}}

    expanding_inames = sweep_inames_set | frozenset(expanding_usage_arg_deps)
    assert expanding_inames <= kernel.all_inames()

    if storage_axis_names:
        # {{{ find domain to be changed

        change_inames = expanding_inames | preexisting_precompute_inames

        from loopy.kernel.tools import DomainChanger
        domch = DomainChanger(kernel, change_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 sweep_inames_set:
                if kernel.get_home_domain_index(iname) != domch.leaf_domain_index:
                    raise RuntimeError("sweep iname '%s' is not 'at home' in the "
                            "sweep's leaf domain" % iname)

        # }}}

        abm = ArrayToBufferMap(kernel, domch.domain, sweep_inames,
                access_descriptors, len(storage_axis_names))

        non1_storage_axis_names = []
        for i, saxis in enumerate(storage_axis_names):
            if abm.non1_storage_axis_flags[i]:
                non1_storage_axis_names.append(saxis)
            else:
                del new_iname_to_tag[saxis]

                if saxis in preexisting_precompute_inames:
                    raise LoopyError("precompute axis %d (1-based) was "
                            "eliminated as "
                            "having length 1 but also mapped to existing "
                            "iname '%s'" % (i+1, saxis))

        mod_domain = domch.domain

        # {{{ modify the domain, taking into account preexisting inames

        # inames may already exist in mod_domain, add them primed to start
        primed_non1_saxis_names = [
                iname+"'" for iname in non1_storage_axis_names]

        mod_domain = abm.augment_domain_with_sweep(
            domch.domain, primed_non1_saxis_names,
            boxify_sweep=fetch_bounding_box)

        check_domain = mod_domain

        for i, saxis in enumerate(non1_storage_axis_names):
            var_dict = mod_domain.get_var_dict(isl.dim_type.set)

            if saxis in preexisting_precompute_inames:
                # add equality constraint between existing and new variable

                dt, dim_idx = var_dict[saxis]
                saxis_aff = isl.Aff.var_on_domain(mod_domain.space, dt, dim_idx)

                dt, dim_idx = var_dict[primed_non1_saxis_names[i]]
                new_var_aff = isl.Aff.var_on_domain(mod_domain.space, dt, dim_idx)

                mod_domain = mod_domain.add_constraint(
                        isl.Constraint.equality_from_aff(new_var_aff - saxis_aff))

                # project out the new one
                mod_domain = mod_domain.project_out(dt, dim_idx, 1)

            else:
                # remove the prime from the new variable
                dt, dim_idx = var_dict[primed_non1_saxis_names[i]]
                mod_domain = mod_domain.set_dim_name(dt, dim_idx, saxis)

        # {{{ check that we got the desired domain

        check_domain = check_domain.project_out_except(
                primed_non1_saxis_names, [isl.dim_type.set])

        mod_check_domain = mod_domain

        # re-add the prime from the new variable
        var_dict = mod_check_domain.get_var_dict(isl.dim_type.set)

        for saxis in non1_storage_axis_names:
            dt, dim_idx = var_dict[saxis]
            mod_check_domain = mod_check_domain.set_dim_name(dt, dim_idx, saxis+"'")

        mod_check_domain = mod_check_domain.project_out_except(
                primed_non1_saxis_names, [isl.dim_type.set])

        mod_check_domain, check_domain = isl.align_two(
                mod_check_domain, check_domain)

        # The modified domain can't get bigger by adding constraints
        assert mod_check_domain <= check_domain

        if not check_domain <= mod_check_domain:
            print(check_domain)
            print(mod_check_domain)
            raise LoopyError("domain of preexisting inames does not match "
                    "domain needed for precompute")

        # }}}

        # {{{ check that we didn't shrink the original domain

        # project out the new names from the modified domain
        orig_domain_inames = list(domch.domain.get_var_dict(isl.dim_type.set))
        mod_check_domain = mod_domain.project_out_except(
                orig_domain_inames, [isl.dim_type.set])

        check_domain = domch.domain

        mod_check_domain, check_domain = isl.align_two(
                mod_check_domain, check_domain)

        # The modified domain can't get bigger by adding constraints
        assert mod_check_domain <= check_domain

        if not check_domain <= mod_check_domain:
            print(check_domain)
            print(mod_check_domain)
            raise LoopyError("original domain got shrunk by applying the precompute")

        # }}}

        # }}}

        new_kernel_domains = domch.get_domains_with(mod_domain)

    else:
        # leave kernel domains unchanged
        new_kernel_domains = kernel.domains

        non1_storage_axis_names = []
        abm = NoOpArrayToBufferMap()

    kernel = kernel.copy(domains=new_kernel_domains)

    # {{{ set up compute insn

    if temporary_name is None:
        temporary_name = var_name_gen(based_on=c_subst_name)

    assignee = var(temporary_name)

    if non1_storage_axis_names:
        assignee = assignee.index(
                tuple(var(iname) for iname in non1_storage_axis_names))

    # {{{ process substitutions on compute instruction

    storage_axis_subst_dict = {}

    for arg_name, bi in zip(storage_axis_names, abm.storage_base_indices):
        if arg_name in non1_storage_axis_names:
            arg = var(arg_name)
        else:
            arg = 0

        storage_axis_subst_dict[
                prior_storage_axis_name_dict.get(arg_name, arg_name)] = arg+bi

    rule_mapping_context = SubstitutionRuleMappingContext(
            kernel.substitutions, kernel.get_var_name_generator())

    from loopy.context_matching import parse_stack_match
    expr_subst_map = RuleAwareSubstitutionMapper(
            rule_mapping_context,
            make_subst_func(storage_axis_subst_dict),
            within=parse_stack_match(None))

    compute_expression = expr_subst_map(subst.expression, kernel, None)

    # }}}

    from loopy.kernel.data import Assignment
    if compute_insn_id is None:
        compute_insn_id = kernel.make_unique_instruction_id(based_on=c_subst_name)

    compute_insn = Assignment(
            id=compute_insn_id,
            assignee=assignee,
            expression=compute_expression)

    # }}}

    # {{{ substitute rule into expressions in kernel (if within footprint)

    invr = RuleInvocationReplacer(rule_mapping_context,
            subst_name, subst_tag, within,
            access_descriptors, abm,
            storage_axis_names, storage_axis_sources,
            non1_storage_axis_names,
            temporary_name, compute_insn_id)

    kernel = invr.map_kernel(kernel)
    kernel = kernel.copy(
            instructions=[compute_insn] + kernel.instructions)
    kernel = rule_mapping_context.finish_kernel(kernel)

    # }}}

    # {{{ set up temp variable

    import loopy as lp
    if dtype is None:
        dtype = lp.auto
    else:
        dtype = np.dtype(dtype)

    import loopy as lp

    if temporary_is_local is None:
        temporary_is_local = lp.auto

    new_temp_shape = tuple(abm.non1_storage_shape)

    new_temporary_variables = kernel.temporary_variables.copy()
    if temporary_name not in new_temporary_variables:
        temp_var = lp.TemporaryVariable(
                name=temporary_name,
                dtype=dtype,
                base_indices=(0,)*len(new_temp_shape),
                shape=tuple(abm.non1_storage_shape),
                is_local=temporary_is_local)

    else:
        temp_var = new_temporary_variables[temporary_name]

        # {{{ check and adapt existing temporary

        if temp_var.dtype is lp.auto:
            pass
        elif temp_var.dtype is not lp.auto and dtype is lp.auto:
            dtype = temp_var.dtype
        elif temp_var.dtype is not lp.auto and dtype is not lp.auto:
            if temp_var.dtype != dtype:
                raise LoopyError("Existing and new dtype of temporary '%s' "
                        "do not match (existing: %s, new: %s)"
                        % (temporary_name, temp_var.dtype, dtype))

        temp_var = temp_var.copy(dtype=dtype)

        if len(temp_var.shape) != len(new_temp_shape):
            raise LoopyError("Existing and new temporary '%s' do not "
                    "have matching number of dimensions "
                    % (temporary_name,
                        len(temp_var.shape), len(new_temp_shape)))

        if temp_var.base_indices != (0,) * len(new_temp_shape):
            raise LoopyError("Existing and new temporary '%s' do not "
                    "have matching number of dimensions "
                    % (temporary_name,
                        len(temp_var.shape), len(new_temp_shape)))

        new_temp_shape = tuple(
                max(i, ex_i)
                for i, ex_i in zip(new_temp_shape, temp_var.shape))

        temp_var = temp_var.copy(shape=new_temp_shape)

        if temporary_is_local == temp_var.is_local:
            pass
        elif temporary_is_local is lp.auto:
            temporary_is_local = temp_var.is_local
        elif temp_var.is_local is lp.auto:
            pass
        else:
            raise LoopyError("Existing and new temporary '%s' do not "
                    "have matching values of 'is_local'"
                    % (temporary_name,
                        temp_var.is_local, temporary_is_local))

        temp_var = temp_var.copy(is_local=temporary_is_local)

        # }}}

    new_temporary_variables[temporary_name] = temp_var

    kernel = kernel.copy(
            temporary_variables=new_temporary_variables)

    # }}}

    from loopy import tag_inames
    kernel = tag_inames(kernel, new_iname_to_tag)

    from loopy.kernel.data import AutoFitLocalIndexTag
    has_automatic_axes = any(
            isinstance(tag, AutoFitLocalIndexTag)
            for tag in new_iname_to_tag.values())

    if has_automatic_axes:
        from loopy.kernel.tools import assign_automatic_axes
        kernel = assign_automatic_axes(kernel)

    return kernel