Exemplo n.º 1
0
    def emit_sequential_loop(self, codegen_state, iname, iname_dtype,
            static_lbound, static_ubound, inner):
        ecm = codegen_state.expression_to_code_mapper

        from loopy.symbolic import aff_to_expr

        from loopy.codegen import wrap_in
        from pymbolic.mapper.stringifier import PREC_NONE
        from cgen import For

        return wrap_in(For,
                "%s %s = %s"
                % (self.dtype_to_typename(iname_dtype),
                    iname, ecm(aff_to_expr(static_lbound), PREC_NONE, "i")),
                "%s <= %s" % (
                    iname, ecm(aff_to_expr(static_ubound), PREC_NONE, "i")),
                "++%s" % iname,
                inner)
Exemplo n.º 2
0
def generate_sequential_loop_dim_code(kernel, sched_index, codegen_state):
    ecm = codegen_state.expression_to_code_mapper
    loop_iname = kernel.schedule[sched_index].iname

    slabs = get_slab_decomposition(
            kernel, loop_iname, sched_index, codegen_state)

    from loopy.codegen.bounds import get_usable_inames_for_conditional

    # Note: this does not include loop_iname itself!
    usable_inames = get_usable_inames_for_conditional(kernel, sched_index)
    domain = kernel.get_inames_domain(loop_iname)

    result = []

    for slab_name, slab in slabs:
        cmt = "%s slab for '%s'" % (slab_name, loop_iname)
        if len(slabs) == 1:
            cmt = None

        # {{{ find bounds

        aligned_domain = isl.align_spaces(domain, slab, across_dim_types=True,
                obj_bigger_ok=True)

        dom_and_slab = aligned_domain & slab

        assumptions_non_param = isl.BasicSet.from_params(kernel.assumptions)
        dom_and_slab, assumptions_non_param = isl.align_two(
                dom_and_slab, assumptions_non_param)
        dom_and_slab = dom_and_slab & assumptions_non_param

        # move inames that are usable into parameters
        moved_inames = []
        for iname in dom_and_slab.get_var_names(dim_type.set):
            if iname in usable_inames:
                moved_inames.append(iname)
                dt, idx = dom_and_slab.get_var_dict()[iname]
                dom_and_slab = dom_and_slab.move_dims(
                        dim_type.param, dom_and_slab.dim(dim_type.param),
                        dt, idx, 1)

        _, loop_iname_idx = dom_and_slab.get_var_dict()[loop_iname]

        from loopy.isl_helpers import (
                static_min_of_pw_aff,
                static_max_of_pw_aff)

        lbound = (
                kernel.cache_manager.dim_min(
                    dom_and_slab, loop_iname_idx)
                .gist(kernel.assumptions)
                .coalesce())
        ubound = (
            kernel.cache_manager.dim_max(
                dom_and_slab, loop_iname_idx)
            .gist(kernel.assumptions)
            .coalesce())

        static_lbound = static_min_of_pw_aff(
                lbound,
                constants_only=False)
        static_ubound = static_max_of_pw_aff(
                ubound,
                constants_only=False)

        # }}}

        # {{{ find implemented slab, build inner code

        from loopy.isl_helpers import make_slab_from_bound_pwaffs

        # impl_slab may be overapproximated
        impl_slab = make_slab_from_bound_pwaffs(
                dom_and_slab.space,
                loop_iname, static_lbound, static_ubound)

        for iname in moved_inames:
            dt, idx = impl_slab.get_var_dict()[iname]
            impl_slab = impl_slab.move_dims(
                    dim_type.set, impl_slab.dim(dim_type.set),
                    dt, idx, 1)

        new_codegen_state = codegen_state.intersect(impl_slab)

        inner = build_loop_nest(
                intersect_kernel_with_slab(
                    kernel, slab, iname),
                sched_index+1, new_codegen_state)

        # }}}

        if cmt is not None:
            from cgen import Comment
            result.append(Comment(cmt))

        from cgen import Initializer, POD, Const, Line, For
        from loopy.symbolic import aff_to_expr

        if (static_ubound - static_lbound).plain_is_zero():
            # single-trip, generate just a variable assignment, not a loop
            result.append(gen_code_block([
                Initializer(Const(POD(kernel.index_dtype, loop_iname)),
                    ecm(aff_to_expr(static_lbound), PREC_NONE, "i")),
                Line(),
                inner,
                ]))

        else:
            from loopy.codegen import wrap_in

            result.append(wrap_in(For,
                    "%s %s = %s"
                    % (kernel.target.dtype_to_typename(kernel.index_dtype),
                        loop_iname, ecm(aff_to_expr(static_lbound), PREC_NONE, "i")),
                    "%s <= %s" % (
                        loop_iname, ecm(aff_to_expr(static_ubound), PREC_NONE, "i")),
                    "++%s" % loop_iname,
                    inner))

    return gen_code_block(result)