Exemplo n.º 1
0
def get_elwise_module_descriptor(arguments, operation, name="kernel"):
    from codepy.bpl import BoostPythonModule

    from cgen import FunctionBody, FunctionDeclaration, \
            Value, POD, Struct, For, Initializer, Include, Statement, \
            Line, Block

    S = Statement

    mod = BoostPythonModule()
    mod.add_to_preamble([
        Include("pyublas/numpy.hpp"),
    ])

    mod.add_to_module([
        S("namespace ublas = boost::numeric::ublas"),
        S("using namespace pyublas"),
        Line(),
    ])

    body = Block([
        Initializer(
            Value("numpy_array<%s >::iterator" % dtype_to_ctype(varg.dtype),
                  varg.name), "args.%s_ary.begin()" % varg.name)
        for varg in arguments if isinstance(varg, VectorArg)
    ] + [
        Initializer(sarg.declarator(), "args." + sarg.name)
        for sarg in arguments if isinstance(sarg, ScalarArg)
    ])

    body.extend([
        Line(),
        For("unsigned i = 0", "i < codepy_length", "++i",
            Block([S(operation)]))
    ])

    arg_struct = Struct("arg_struct", [arg.declarator() for arg in arguments])
    mod.add_struct(arg_struct, "ArgStruct")
    mod.add_to_module([Line()])

    mod.add_function(
        FunctionBody(
            FunctionDeclaration(Value("void", name), [
                POD(numpy.uintp, "codepy_length"),
                Value("arg_struct", "args")
            ]), body))

    return mod
Exemplo n.º 2
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    def index_list_backend(self, ilists):
        from pytools import single_valued
        ilist_length = single_valued(len(il) for il in ilists)
        assert ilist_length == self.plan.dofs_per_face

        from cgen import Typedef, POD

        from pytools import flatten
        flat_ilists_uncast = numpy.array(list(flatten(ilists)))

        if numpy.max(flat_ilists_uncast) >= 256:
            tp = numpy.uint16
        else:
            tp = numpy.uint8

        flat_ilists = numpy.asarray(flat_ilists_uncast, dtype=tp)
        assert (flat_ilists == flat_ilists_uncast).all()

        return GPUIndexLists(
            type=tp,
            code=[Typedef(POD(tp, "index_list_entry_t"))],
            device_memory=cuda.to_device(flat_ilists),
            bytes=flat_ilists.size * flat_ilists.itemsize,
        )
Exemplo n.º 3
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    def write_boundary_flux_code(self, for_benchmark):
        given = self.plan.given

        flux_write_code = Block()

        fluxes_by_bdry_number = {}
        for flux_nr, wdflux in enumerate(self.fluxes):
            for bflux_info in wdflux.boundaries:
                if for_benchmark:
                    bdry_number = 0
                else:
                    bdry_number = self.executor.boundary_tag_to_number[
                        bflux_info.bpair.tag]

                fluxes_by_bdry_number.setdefault(bdry_number, [])\
                        .append((flux_nr, bflux_info))

        flux_write_code.extend([
            Initializer(MaybeUnused(POD(given.float_type, "flux%d" % flux_nr)),
                        0) for flux_nr in range(len(self.fluxes))
        ])

        for bdry_number, nrs_and_fluxes in fluxes_by_bdry_number.iteritems():
            bblock = []

            from pytools import set_sum
            int_deps = set_sum(flux_rec.int_dependencies
                               for flux_nr, flux_rec in nrs_and_fluxes)
            ext_deps = set_sum(flux_rec.ext_dependencies
                               for flux_nr, flux_rec in nrs_and_fluxes)

            for dep in int_deps:
                bblock.extend([
                    Comment(str(dep)),
                    Initializer(
                        MaybeUnused(
                            POD(given.float_type,
                                "val_a_field%d" % self.dep_to_index[dep])),
                        "fp_tex1Dfetch(field%d_tex, a_index)" %
                        self.dep_to_index[dep])
                ])
            for dep in ext_deps:
                bblock.extend([
                    Comment(str(dep)),
                    Initializer(
                        MaybeUnused(
                            POD(given.float_type,
                                "val_b_field%d" % self.dep_to_index[dep])),
                        "fp_tex1Dfetch(field%s_tex, b_index)" %
                        self.dep_to_index[dep])
                ])

            f2cm = FluxToCodeMapper(given.float_type)

            comp_code = [Line()]
            for flux_nr, flux_rec in nrs_and_fluxes:
                comp_code.append(
                    Statement(
                        ("flux%d += " % flux_nr) +
                        flux_to_code(f2cm,
                                     is_flipped=False,
                                     int_field_expr=flux_rec.bpair.field,
                                     ext_field_expr=flux_rec.bpair.bfield,
                                     dep_to_index=self.dep_to_index,
                                     flux=flux_rec.flux_expr,
                                     prec=PREC_NONE)))

            if f2cm.cse_name_list:
                bblock.append(Line())

            bblock.extend(
                Initializer(Value("value_type", cse_name), cse_str)
                for cse_name, cse_str in f2cm.cse_name_list)

            flux_write_code.extend([
                Line(),
                Comment(nrs_and_fluxes[0][1].bpair.tag),
                If("(fpair->boundary_bitmap) & (1 << %d)" % (bdry_number),
                   Block(bblock + comp_code)),
            ])

        flux_write_code.extend(
            [
                Line(),
            ] + [
                self.gen_store(flux_nr, "fpair->a_dest+FACEDOF_NR",
                               "fpair->face_jacobian * flux%d" % flux_nr)
                for flux_nr in range(len(self.fluxes))
            ]
            #Assign("debugbuf[blockIdx.x*96+fpair_nr]", "10000+fpair->a_dest"),
        )

        return flux_write_code
Exemplo n.º 4
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    def write_interior_flux_code(self, is_twosided):
        given = self.plan.given

        def get_field(flux_rec, is_interior, flipped):
            if is_interior ^ flipped:
                prefix = "a"
            else:
                prefix = "b"

            return ("val_%s_field%d" %
                    (prefix, self.dep_to_index[flux_rec.field_expr]))

        flux_write_code = Block([])

        flux_var_decl = [Initializer(POD(given.float_type, "a_flux"), 0)]

        if is_twosided:
            flux_var_decl.append(
                Initializer(POD(given.float_type, "b_flux"), 0))
            prefixes = ["a", "b"]
            flip_values = [False, True]
        else:
            prefixes = ["a"]
            flip_values = [False]

        flux_write_code.append(Line())

        for dep in self.interior_deps:
            flux_write_code.append(Comment(str(dep)))

            for side in ["a", "b"]:
                flux_write_code.append(
                    Initializer(
                        MaybeUnused(
                            POD(
                                given.float_type, "val_%s_field%d" %
                                (side, self.dep_to_index[dep]))),
                        "fp_tex1Dfetch(field%d_tex, %s_index)" %
                        (self.dep_to_index[dep], side)))

        f2cm = FluxToCodeMapper(given.float_type)

        flux_sub_codes = []
        for flux_nr, wdflux in enumerate(self.fluxes):
            my_flux_block = Block(flux_var_decl)

            for int_rec in wdflux.interiors:
                for prefix, is_flipped in zip(prefixes, flip_values):
                    my_flux_block.append(
                        Statement("%s_flux += %s" % (
                            prefix,
                            flux_to_code(f2cm, is_flipped, int_rec.field_expr,
                                         int_rec.field_expr, self.dep_to_index,
                                         int_rec.flux_expr, PREC_NONE),
                        )))

            my_flux_block.append(Line())

            my_flux_block.append(
                self.gen_store(flux_nr, "fpair->a_dest+FACEDOF_NR",
                               "fpair->face_jacobian*a_flux"))

            #my_flux_block.append(
            #Statement("if(isnan(val_b_field5)) debugbuf[blockIdx.x] = 1"),
            #)

            if is_twosided:
                my_flux_block.append(
                    self.gen_store(
                        flux_nr, "fpair->b_dest+tex1Dfetch(tex_index_lists, "
                        "fpair->b_write_ilist_index + FACEDOF_NR)",
                        "fpair->face_jacobian*b_flux"))

                #my_flux_block.append(
                #Assign("debugbuf[blockIdx.x*96+fpair_nr+8]", "10000+fpair->b_dest"),
                #)

            flux_sub_codes.append(my_flux_block)

        if f2cm.cse_name_list:
            flux_write_code.append(Line())

        flux_write_code.extend(
            Initializer(Value("value_type", cse_name), cse_str)
            for cse_name, cse_str in f2cm.cse_name_list)

        flux_write_code.extend(flux_sub_codes)

        return flux_write_code
Exemplo n.º 5
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def face_pair_struct(float_type, dims):
    from cgen import GenerableStruct
    return GenerableStruct(
        "face_pair",
        [
            POD(
                float_type,
                "h",
            ),
            POD(float_type, "order"),
            POD(float_type, "face_jacobian"),
            ArrayOf(POD(float_type, "normal"), dims),
            POD(numpy.uint32, "a_base"),
            POD(numpy.uint32, "b_base"),
            POD(numpy.uint16, "a_ilist_index"),
            POD(numpy.uint16, "b_ilist_index"),
            POD(numpy.uint16, "b_write_ilist_index"),
            POD(numpy.uint16, "boundary_bitmap"),
            POD(numpy.uint16, "a_dest"),
            POD(numpy.uint16, "b_dest"),
        ],

        # ensure that adjacent face_pair instances can be accessed
        # without bank conflicts.
        aligned_prime_to=[2],
    )
Exemplo n.º 6
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    def make_lift(self, fgroup, with_scale, dtype):
        discr = self.discr
        from cgen import (FunctionDeclaration, FunctionBody, Typedef, Const,
                          Reference, Value, POD, Statement, Include, Line,
                          Block, Initializer, Assign, For, If, Define)

        from pytools import to_uncomplex_dtype

        from codepy.bpl import BoostPythonModule
        mod = BoostPythonModule()

        S = Statement
        mod.add_to_preamble([
            Include("hedge/face_operators.hpp"),
            Include("hedge/volume_operators.hpp"),
            Include("boost/foreach.hpp"),
        ])

        mod.add_to_module([
            S("namespace ublas = boost::numeric::ublas"),
            S("using namespace hedge"),
            S("using namespace pyublas"),
            Line(),
            Define("DOFS_PER_EL", fgroup.ldis_loc.node_count()),
            Define("FACES_PER_EL", fgroup.ldis_loc.face_count()),
            Define("DIMENSIONS", discr.dimensions),
            Line(),
            Typedef(POD(dtype, "value_type")),
            Typedef(POD(to_uncomplex_dtype(dtype), "uncomplex_type")),
        ])

        def if_(cond, result, else_=None):
            if cond:
                return [result]
            else:
                if else_ is None:
                    return []
                else:
                    return [else_]

        fdecl = FunctionDeclaration(Value("void", "lift"), [
            Const(
                Reference(Value("face_group<face_pair<straight_face> >",
                                "fg"))),
            Value("ublas::matrix<uncomplex_type>", "matrix"),
            Value("numpy_array<value_type>", "field"),
            Value("numpy_array<value_type>", "result")
        ] + if_(
            with_scale,
            Const(
                Reference(Value("numpy_array<double>",
                                "elwise_post_scaling")))))

        def make_it(name, is_const=True, tpname="value_type"):
            if is_const:
                const = "const_"
            else:
                const = ""

            return Initializer(
                Value("numpy_array<%s>::%siterator" % (tpname, const),
                      name + "_it"), "%s.begin()" % name)

        fbody = Block([
            make_it("field"),
            make_it("result", is_const=False),
        ] + if_(with_scale, make_it("elwise_post_scaling", tpname="double")) + [
            Line(),
            For(
                "unsigned fg_el_nr = 0", "fg_el_nr < fg.element_count()",
                "++fg_el_nr",
                Block([
                    Initializer(Value("node_number_t", "dest_el_base"),
                                "fg.local_el_write_base[fg_el_nr]"),
                    Initializer(Value("node_number_t", "src_el_base"),
                                "FACES_PER_EL*fg.face_length()*fg_el_nr"),
                    Line(),
                    For(
                        "unsigned i = 0", "i < DOFS_PER_EL", "++i",
                        Block([
                            Initializer(Value("value_type", "tmp"), 0),
                            Line(),
                            For(
                                "unsigned j = 0",
                                "j < FACES_PER_EL*fg.face_length()", "++j",
                                S("tmp += matrix(i, j)*field_it[src_el_base+j]"
                                  )),
                            Line(),
                        ] + if_(
                            with_scale,
                            Assign(
                                "result_it[dest_el_base+i]",
                                "tmp * value_type(*elwise_post_scaling_it)"),
                            Assign("result_it[dest_el_base+i]", "tmp")))),
                ] + if_(with_scale, S("elwise_post_scaling_it++"))))
        ])

        mod.add_function(FunctionBody(fdecl, fbody))

        #print "----------------------------------------------------------------"
        #print FunctionBody(fdecl, fbody)
        #raw_input()

        return mod.compile(self.discr.toolchain).lift
Exemplo n.º 7
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    def make_cuda_kernel(self, discr, dtype, eg):
        given = discr.given
        ldis = eg.local_discretization

        microblocks_per_block = 1

        from cgen.cuda import CudaGlobal

        from cgen import (Module, Value, Include,
                Typedef, FunctionBody, FunctionDeclaration, Const,
                Line, POD, LiteralBlock,
                Define, Pointer)

        cmod = Module([
            Include("pycuda-helpers.hpp"),
            Line(),
            Typedef(POD(dtype, "value_type")),
            Line(),
            Define("DOFS_PER_EL", given.dofs_per_el()),
            Define("ALIGNED_DOFS_PER_MB", given.microblock.aligned_floats),
            Define("VERTICES_PER_EL", ldis.vertex_count()),
            Define("ELS_PER_MB", given.microblock.elements),
            Define("MBS_PER_BLOCK", microblocks_per_block),
            Line(),
            Define("DOF_IN_MB_IDX", "threadIdx.x"),
            Define("DOF_IN_EL_IDX", "(DOF_IN_MB_IDX-el_idx_in_mb*DOFS_PER_EL)"),
            Define("MB_IN_BLOCK_IDX", "threadIdx.y"),
            Define("BLOCK_IDX", "blockIdx.x"),
            Define("MB_NUMBER", "(BLOCK_IDX * MBS_PER_BLOCK + MB_IN_BLOCK_IDX)"),
            Define("BLOCK_DATA", "whole_block[MB_IN_BLOCK_IDX]")]
            + self.get_cuda_extra_preamble(discr, dtype, eg)
            + [FunctionBody(
            CudaGlobal(FunctionDeclaration(
                    Value("void", "elwise_kernel"), [
                    Pointer(Const(POD(dtype, "field"))),
                    Pointer(POD(dtype, "result")),
                    POD(numpy.uint32, "mb_count"),
                    ])),
                LiteralBlock("""
                int el_idx_in_mb = DOF_IN_MB_IDX / DOFS_PER_EL;

                if (MB_NUMBER >= mb_count)
                  return;

                int idx =  MB_NUMBER * ALIGNED_DOFS_PER_MB + DOF_IN_MB_IDX;
                int element_base_idx = ALIGNED_DOFS_PER_MB * MB_IN_BLOCK_IDX +
                    (DOF_IN_MB_IDX / DOFS_PER_EL) * DOFS_PER_EL;
                int dof_in_element = DOF_IN_MB_IDX-el_idx_in_mb*DOFS_PER_EL;

                __shared__ value_type whole_block[MBS_PER_BLOCK][ALIGNED_DOFS_PER_MB+1];
                int idx_in_block = ALIGNED_DOFS_PER_MB * MB_IN_BLOCK_IDX + DOF_IN_MB_IDX;
                BLOCK_DATA[idx_in_block] = field[idx];

                __syncthreads();

                %s

                result[idx] = node_result;
                """ % self.get_cuda_code(discr, dtype, eg)))
                ])


        if False:
            for i, l in enumerate(str(cmod).split("\n")):
                print i+1, l
            raw_input()

        from pycuda.compiler import SourceModule
        mod = SourceModule(
                cmod,
                keep="cuda_keep_kernels" in discr.debug,
                )
        func = mod.get_function("elwise_kernel")
        func.prepare(
            "PPI", block=(
                given.microblock.aligned_floats,
                microblocks_per_block, 1))

        mb_count = len(discr.blocks) * discr.given.microblocks_per_block
        grid_dim = (mb_count + microblocks_per_block - 1) \
                // microblocks_per_block

        from pytools import Record
        class KernelInfo(Record):
            pass

        return KernelInfo(
                func=func,
                grid_dim=grid_dim,
                mb_count=mb_count)
Exemplo n.º 8
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def test_cgen():
    s = Struct(
        "yuck",
        [
            POD(
                np.float32,
                "h",
            ),
            POD(np.float32, "order"),
            POD(np.float32, "face_jacobian"),
            ArrayOf(POD(np.float32, "normal"), 17),
            POD(np.uint16, "a_base"),
            POD(np.uint16, "b_base"),
            #CudaGlobal(POD(np.uint8, "a_ilist_number")),
            POD(np.uint8, "b_ilist_number"),
            POD(np.uint8, "bdry_flux_number"),  # 0 if not on boundary
            POD(np.uint8, "reserved"),
            POD(np.uint32, "b_global_base"),
        ])
    u = Union(
        "yuck",
        [
            POD(
                np.float32,
                "h",
            ),
            POD(np.float32, "order"),
            POD(np.float32, "face_jacobian"),
            ArrayOf(POD(np.float32, "normal"), 17),
            POD(np.uint16, "a_base"),
            POD(np.uint16, "b_base"),
            #CudaGlobal(POD(np.uint8, "a_ilist_number")),
            POD(np.uint8, "b_ilist_number"),
            POD(np.uint8, "bdry_flux_number"),  # 0 if not on boundary
            POD(np.uint8, "reserved"),
            POD(np.uint32, "b_global_base"),
        ])
    f_decl = FunctionDeclaration(POD(np.uint16, "get_num"), [
        POD(np.uint8, "reserved"),
        POD(np.uint32, "b_global_base"),
    ])
    f_body = FunctionBody(
        f_decl,
        Block([
            POD(np.uint32, "i"),
            For(
                "i = 0",
                "i < 17",
                "++i",
                If(
                    "a > b",
                    Assign("a", "b"),
                    Block([
                        Assign("a", "b-1"),
                        #Break(),
                    ])),
            ),
            #BlankLine(),
            Comment("all done"),
        ]))
    t_decl = Template(
        'typename T',
        FunctionDeclaration(
            Value('CUdeviceptr', 'scan'),
            [Value('CUdeviceptr', 'inputPtr'),
             Value('int', 'length')]))

    print(s)
    print(u)
    print(f_body)
    print(t_decl)
Exemplo n.º 9
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        def get_scalar_diff_code():
            code = []
            for inl in range(par.inline):
                for axis in dims:
                    code.append(
                        Initializer(POD(float_type, "d%drst%d" % (inl, axis)), 0))

            code.append(Line())

            tex_channels = ["x", "y", "z", "w"]

            store_code = Block()
            for inl in range(par.inline):
                for rst_axis in dims:
                    store_code.append(Assign(
                        "drst%d_global[GLOBAL_MB_IMAGE_DOF_BASE + "
                        "%d*ALIGNED_IMAGE_DOFS_PER_MB + IMAGE_MB_DOF]"
                        % (rst_axis, inl),
                        "d%drst%d" % (inl, rst_axis)
                        ))

            from hedge.backends.cuda.tools import unroll
            code.extend([
                Comment("everybody needs to be done with the old data"),
                S("__syncthreads()"),
                Line(),
                get_load_code(),
                Line(),
                Comment("all the new data must be loaded"),
                S("__syncthreads()"),
                Line(),
                ])

            if float_type == numpy.float32:
                code.append(Value("float%d" % rst_channels, "dmat_entries"))

            code.extend([
                POD(float_type, "field_value%d" % inl)
                for inl in range(par.inline)
                ]+[Line()])

            def unroll_body(j):
                result = [
                    Assign("field_value%d" % inl,
                        "smem_field[PAR_MB_NR][%d][mb_el*PREIMAGE_DOFS_PER_EL+%s]" % (inl, j))
                    for inl in range(par.inline)
                    ]

                if float_type == numpy.float32:
                    result.append(Assign("dmat_entries",
                        "tex1Dfetch(diff_rst_mat_tex, IMAGE_EL_DOF + %s*IMAGE_DOFS_PER_EL)" % j))
                    result.extend(
                        S("d%drst%d += dmat_entries.%s * field_value%d"
                            % (inl, axis, tex_channels[axis], inl))
                        for inl in range(par.inline)
                        for axis in dims)
                elif float_type == numpy.float64:
                    result.extend(
                        S("d%(inl)drst%(axis)d += "
                            "fp_tex1Dfetch(diff_rst_mat_tex, %(axis)d "
                            "+ DIMENSIONS*(IMAGE_EL_DOF + %(j)d*IMAGE_DOFS_PER_EL))"
                            "* field_value%(inl)d" % {
                            "inl": inl,
                            "axis": axis,
                            "j": j
                            })
                        for inl in range(par.inline)
                        for axis in dims)
                else:
                    assert False

                return result

            code.append(If("IMAGE_MB_DOF < IMAGE_DOFS_PER_MB", Block(unroll(unroll_body,
                    total_number=plan.preimage_dofs_per_el)
                    +[store_code])))

            return code
Exemplo n.º 10
0
    def get_kernel(self, diff_op_cls, elgroup, for_benchmark=False):
        from cgen import \
                Pointer, POD, Value, ArrayOf, \
                Module, FunctionDeclaration, FunctionBody, Block, \
                Line, Define, Include, \
                Initializer, If, For, Statement, Assign

        from cgen import dtype_to_ctype
        from cgen.cuda import CudaShared, CudaGlobal

        discr = self.discr
        d = discr.dimensions
        dims = range(d)
        given = self.plan.given

        par = self.plan.parallelism

        diffmat_data = self.gpu_diffmats(diff_op_cls, elgroup)
        elgroup, = discr.element_groups

        float_type = given.float_type

        f_decl = CudaGlobal(
            FunctionDeclaration(
                Value("void", "apply_diff_mat"),
                [
                    Pointer(POD(numpy.uint8, "gmem_diff_rst_mat")),
                    #Pointer(POD(float_type, "debugbuf")),
                ] +
                [Pointer(POD(float_type, "drst%d_global" % i)) for i in dims]))

        rst_channels = given.devdata.make_valid_tex_channel_count(d)
        cmod = Module([
            Include("pycuda-helpers.hpp"),
            Line(),
            Value(
                "texture<fp_tex_%s, 1, cudaReadModeElementType>" %
                dtype_to_ctype(float_type), "field_tex"),
            Line(),
            Define("DIMENSIONS", discr.dimensions),
            Define("DOFS_PER_EL", given.dofs_per_el()),
            Line(),
            Define("SEGMENT_DOF", "threadIdx.x"),
            Define("PAR_MB_NR", "threadIdx.y"),
            Line(),
            Define("MB_SEGMENT", "blockIdx.x"),
            Define("MACROBLOCK_NR", "blockIdx.y"),
            Line(),
            Define("DOFS_PER_SEGMENT", self.plan.segment_size),
            Define("SEGMENTS_PER_MB", self.plan.segments_per_microblock()),
            Define("ALIGNED_DOFS_PER_MB", given.microblock.aligned_floats),
            Define("ELS_PER_MB", given.microblock.elements),
            Line(),
            Define("PAR_MB_COUNT", par.parallel),
            Define("INLINE_MB_COUNT", par.inline),
            Define("SEQ_MB_COUNT", par.serial),
            Line(),
            Define("THREAD_NUM", "(SEGMENT_DOF+PAR_MB_NR*DOFS_PER_SEGMENT)"),
            Define("COALESCING_THREAD_COUNT",
                   "(PAR_MB_COUNT*DOFS_PER_SEGMENT)"),
            Line(),
            Define("MB_DOF_BASE", "(MB_SEGMENT*DOFS_PER_SEGMENT)"),
            Define("MB_DOF", "(MB_DOF_BASE+SEGMENT_DOF)"),
            Define(
                "GLOBAL_MB_NR_BASE",
                "(MACROBLOCK_NR*PAR_MB_COUNT*INLINE_MB_COUNT*SEQ_MB_COUNT)"),
            Define(
                "GLOBAL_MB_NR", "(GLOBAL_MB_NR_BASE"
                "+ (seq_mb_number*PAR_MB_COUNT + PAR_MB_NR)*INLINE_MB_COUNT)"),
            Define("GLOBAL_MB_DOF_BASE", "(GLOBAL_MB_NR*ALIGNED_DOFS_PER_MB)"),
            Line(),
            Define("DIFFMAT_SEGMENT_FLOATS", diffmat_data.block_floats),
            Define("DIFFMAT_SEGMENT_BYTES",
                   "(DIFFMAT_SEGMENT_FLOATS*%d)" % given.float_size()),
            Define("DIFFMAT_COLUMNS", diffmat_data.matrix_columns),
            Line(),
            CudaShared(
                ArrayOf(POD(float_type, "smem_diff_rst_mat"),
                        "DIFFMAT_COLUMNS*DOFS_PER_SEGMENT")),
            Line(),
        ])

        S = Statement
        f_body = Block()

        f_body.extend_log_block("calculate responsibility data", [
            Initializer(POD(numpy.uint16, "mb_el"), "MB_DOF/DOFS_PER_EL"),
        ])

        from hedge.backends.cuda.tools import get_load_code
        f_body.extend(
            get_load_code(
                dest="smem_diff_rst_mat",
                base="gmem_diff_rst_mat + MB_SEGMENT*DIFFMAT_SEGMENT_BYTES",
                bytes="DIFFMAT_SEGMENT_BYTES",
                descr="load diff mat segment") +
            [S("__syncthreads()"), Line()])

        # ---------------------------------------------------------------------
        def get_scalar_diff_code():
            code = []
            for inl in range(par.inline):
                for axis in dims:
                    code.append(
                        Initializer(POD(float_type, "d%drst%d" % (inl, axis)),
                                    0))

            code.append(Line())

            def get_mat_entry(row, col, axis):
                return ("smem_diff_rst_mat["
                        "%(row)s*DIFFMAT_COLUMNS + %(axis)s*DOFS_PER_EL"
                        " + %(col)s"
                        "]" % {
                            "row": row,
                            "col": col,
                            "axis": axis
                        })

            tex_channels = ["x", "y", "z", "w"]
            from hedge.backends.cuda.tools import unroll
            code.extend([
                POD(float_type, "field_value%d" % inl)
                for inl in range(par.inline)
            ] + [Line()] + unroll(
                lambda j: [
                    Assign(
                        "field_value%d" % inl,
                        "fp_tex1Dfetch(field_tex, GLOBAL_MB_DOF_BASE + %d*ALIGNED_DOFS_PER_MB "
                        "+ mb_el*DOFS_PER_EL + %s)" % (inl, j))
                    for inl in range(par.inline)
                ] + [Line()] + [
                    S("d%drst%d += %s * field_value%d" %
                      (inl, axis, get_mat_entry("SEGMENT_DOF", j, axis), inl))
                    for axis in dims for inl in range(par.inline)
                ] + [Line()], given.dofs_per_el(), self.plan.max_unroll))

            store_code = Block()
            for inl in range(par.inline):
                for rst_axis in dims:
                    store_code.append(
                        Assign(
                            "drst%d_global[GLOBAL_MB_DOF_BASE"
                            " + %d*ALIGNED_DOFS_PER_MB + MB_DOF]" %
                            (rst_axis, inl),
                            "d%drst%d" % (inl, rst_axis),
                        ))

            code.append(If("MB_DOF < DOFS_PER_EL*ELS_PER_MB", store_code))

            return code

        f_body.extend([
            For("unsigned short seq_mb_number = 0",
                "seq_mb_number < SEQ_MB_COUNT", "++seq_mb_number",
                Block(get_scalar_diff_code()))
        ])

        # finish off ----------------------------------------------------------
        cmod.append(FunctionBody(f_decl, f_body))

        if not for_benchmark and "cuda_dump_kernels" in discr.debug:
            from hedge.tools import open_unique_debug_file
            open_unique_debug_file("diff", ".cu").write(str(cmod))

        mod = SourceModule(
            cmod,
            keep="cuda_keep_kernels" in discr.debug,
            #options=["--maxrregcount=10"]
        )

        field_texref = mod.get_texref("field_tex")

        func = mod.get_function("apply_diff_mat")
        func.prepare(discr.dimensions * [float_type] + ["P"],
                     block=(self.plan.segment_size, par.parallel, 1),
                     texrefs=[field_texref])

        if "cuda_diff" in discr.debug:
            print "diff: lmem=%d smem=%d regs=%d" % (
                func.local_size_bytes, func.shared_size_bytes, func.num_regs)

        return func, field_texref
Exemplo n.º 11
0
 def declarator(self):
     return POD(self.dtype, self.name)
Exemplo n.º 12
0
a_buf = cl.Buffer(ctx, mf.READ_ONLY | mf.COPY_HOST_PTR, hostbuf=a)
b_buf = cl.Buffer(ctx, mf.READ_ONLY | mf.COPY_HOST_PTR, hostbuf=b)
c_buf = cl.Buffer(ctx, mf.WRITE_ONLY, b.nbytes)

from cgen import FunctionBody, \
        FunctionDeclaration, Typedef, POD, Value, \
        Pointer, Module, Block, Initializer, Assign, Const
from cgen.opencl import CLKernel, CLGlobal, \
        CLRequiredWorkGroupSize

mod = Module([
    FunctionBody(
        CLKernel(CLRequiredWorkGroupSize((local_size,),
            FunctionDeclaration(
            Value("void", "add"),
            arg_decls=[CLGlobal(Pointer(Const(POD(dtype, name))))
                for name in ["tgt", "op1", "op2"]]))),
        Block([
            Initializer(POD(numpy.int32, "idx"),
                "get_local_id(0) + %d * get_group_id(0)"
                % (local_size*thread_strides))
            ]+[
            Assign(
                "tgt[idx+%d]" % (o*local_size),
                "op1[idx+%d] + op2[idx+%d]" % (
                    o*local_size,
                    o*local_size))
            for o in range(thread_strides)]))])

knl = cl.Program(ctx, str(mod)).build().add
Exemplo n.º 13
0
def test_ptr_to_array():
    t1 = Pointer(ArrayOf(Pointer(POD(np.float32, "xxx")), 2))
    assert str(t1) == "float *((*xxx)[2]);"

    t2 = Pointer(Pointer(ArrayOf(POD(np.float32, "yyy"), 2)))
    assert str(t2) == "float **(yyy[2]);"
Exemplo n.º 14
0
    def get_kernel(self, with_scaling, for_benchmark=False):
        from cgen import \
                Pointer, POD, Value, ArrayOf, \
                Module, FunctionDeclaration, FunctionBody, Block, \
                Line, Define, Include, \
                Initializer, If, For, Statement, Assign, \
                ArrayInitializer

        from cgen import dtype_to_ctype
        from cgen.cuda import CudaShared, CudaConstant, CudaGlobal

        discr = self.discr
        d = discr.dimensions
        dims = range(d)
        given = self.plan.given

        float_type = given.float_type

        f_decl = CudaGlobal(
            FunctionDeclaration(Value("void", "apply_el_local_mat_smem_mat"), [
                Pointer(POD(float_type, "out_vector")),
                Pointer(POD(numpy.uint8, "gmem_matrix")),
                Pointer(POD(float_type, "debugbuf")),
                POD(numpy.uint32, "microblock_count"),
            ]))

        cmod = Module([
            Include("pycuda-helpers.hpp"),
            Line(),
            Value(
                "texture<fp_tex_%s, 1, cudaReadModeElementType>" %
                dtype_to_ctype(float_type), "in_vector_tex"),
        ])
        if with_scaling:
            cmod.append(
                Value(
                    "texture<fp_tex_%s, 1, cudaReadModeElementType>" %
                    dtype_to_ctype(float_type), "scaling_tex"), )

        par = self.plan.parallelism

        cmod.extend([
            Line(),
            Define("DIMENSIONS", discr.dimensions),
            Define("DOFS_PER_EL", given.dofs_per_el()),
            Define("PREIMAGE_DOFS_PER_EL", self.plan.preimage_dofs_per_el),
            Line(),
            Define("SEGMENT_DOF", "threadIdx.x"),
            Define("PAR_MB_NR", "threadIdx.y"),
            Line(),
            Define("MB_SEGMENT", "blockIdx.x"),
            Define("MACROBLOCK_NR", "blockIdx.y"),
            Line(),
            Define("DOFS_PER_SEGMENT", self.plan.segment_size),
            Define("SEGMENTS_PER_MB", self.plan.segments_per_microblock()),
            Define("ALIGNED_DOFS_PER_MB", given.microblock.aligned_floats),
            Define("ALIGNED_PREIMAGE_DOFS_PER_MB",
                   self.plan.aligned_preimage_dofs_per_microblock),
            Define("MB_EL_COUNT", given.microblock.elements),
            Line(),
            Define("PAR_MB_COUNT", par.parallel),
            Define("INLINE_MB_COUNT", par.inline),
            Define("SEQ_MB_COUNT", par.serial),
            Line(),
            Define("THREAD_NUM", "(SEGMENT_DOF+PAR_MB_NR*DOFS_PER_SEGMENT)"),
            Define("COALESCING_THREAD_COUNT",
                   "(PAR_MB_COUNT*DOFS_PER_SEGMENT)"),
            Line(),
            Define("MB_DOF_BASE", "(MB_SEGMENT*DOFS_PER_SEGMENT)"),
            Define("MB_DOF", "(MB_DOF_BASE+SEGMENT_DOF)"),
            Define(
                "GLOBAL_MB_NR_BASE",
                "(MACROBLOCK_NR*PAR_MB_COUNT*INLINE_MB_COUNT*SEQ_MB_COUNT)"),
            Define(
                "GLOBAL_MB_NR", "(GLOBAL_MB_NR_BASE"
                "+ (seq_mb_number*PAR_MB_COUNT + PAR_MB_NR)*INLINE_MB_COUNT)"),
            Define("GLOBAL_MB_DOF_BASE", "(GLOBAL_MB_NR*ALIGNED_DOFS_PER_MB)"),
            Define("GLOBAL_MB_PREIMG_DOF_BASE",
                   "(GLOBAL_MB_NR*ALIGNED_PREIMAGE_DOFS_PER_MB)"),
            Line(),
            Define("MATRIX_COLUMNS", self.plan.gpu_matrix_columns()),
            Define("MATRIX_SEGMENT_FLOATS",
                   self.plan.gpu_matrix_block_floats()),
            Define("MATRIX_SEGMENT_BYTES",
                   "(MATRIX_SEGMENT_FLOATS*%d)" % given.float_size()),
            Line(),
            CudaShared(
                ArrayOf(POD(float_type, "smem_matrix"),
                        "MATRIX_SEGMENT_FLOATS")),
            CudaShared(
                ArrayOf(
                    ArrayOf(
                        ArrayOf(POD(float_type, "dof_buffer"), "PAR_MB_COUNT"),
                        "INLINE_MB_COUNT"), "DOFS_PER_SEGMENT"), ),
            CudaShared(POD(numpy.uint16, "segment_start_el")),
            CudaShared(POD(numpy.uint16, "segment_stop_el")),
            CudaShared(POD(numpy.uint16, "segment_el_count")),
            Line(),
            ArrayInitializer(
                CudaConstant(
                    ArrayOf(POD(numpy.uint32, "segment_start_el_lookup"),
                            "SEGMENTS_PER_MB")),
                [(chk * self.plan.segment_size) // given.dofs_per_el()
                 for chk in range(self.plan.segments_per_microblock())]),
            ArrayInitializer(
                CudaConstant(
                    ArrayOf(POD(numpy.uint32, "segment_stop_el_lookup"),
                            "SEGMENTS_PER_MB")),
                [
                    min(given.microblock.elements,
                        (chk * self.plan.segment_size +
                         self.plan.segment_size - 1) // given.dofs_per_el() +
                        1)
                    for chk in range(self.plan.segments_per_microblock())
                ]),
        ])

        S = Statement
        f_body = Block()

        f_body.extend_log_block(
            "calculate this dof's element",
            [Initializer(POD(numpy.uint8, "mb_el"), "MB_DOF/DOFS_PER_EL")])

        if self.plan.use_prefetch_branch:
            f_body.extend_log_block("calculate segment responsibility data", [
                If(
                    "THREAD_NUM==0",
                    Block([
                        Assign("segment_start_el",
                               "segment_start_el_lookup[MB_SEGMENT]"),
                        Assign("segment_stop_el",
                               "segment_stop_el_lookup[MB_SEGMENT]"),
                        Assign("segment_el_count",
                               "segment_stop_el-segment_start_el"),
                    ])),
                S("__syncthreads()")
            ])

        from hedge.backends.cuda.tools import get_load_code
        f_body.extend(
            get_load_code(dest="smem_matrix",
                          base=(
                              "gmem_matrix + MB_SEGMENT*MATRIX_SEGMENT_BYTES"),
                          bytes="MATRIX_SEGMENT_BYTES",
                          descr="load matrix segment") +
            [S("__syncthreads()")])

        # ---------------------------------------------------------------------
        def get_batched_fetch_mat_mul_code(el_fetch_count):
            result = []
            dofs = range(self.plan.preimage_dofs_per_el)

            for load_segment_start in range(0, self.plan.preimage_dofs_per_el,
                                            self.plan.segment_size):
                result.extend([S("__syncthreads()")] + [
                    Assign(
                        "dof_buffer[PAR_MB_NR][%d][SEGMENT_DOF]" %
                        inl, "fp_tex1Dfetch(in_vector_tex, "
                        "GLOBAL_MB_PREIMG_DOF_BASE"
                        " + %d*ALIGNED_PREIMAGE_DOFS_PER_MB"
                        " + (segment_start_el)*PREIMAGE_DOFS_PER_EL + %d + SEGMENT_DOF)"
                        % (inl, load_segment_start))
                    for inl in range(par.inline)
                ] + [
                    S("__syncthreads()"),
                    Line(),
                ])

                for dof in dofs[load_segment_start:load_segment_start +
                                self.plan.segment_size]:
                    for inl in range(par.inline):
                        result.append(
                            S("result%d += "
                              "smem_matrix[SEGMENT_DOF*MATRIX_COLUMNS + %d]"
                              "*"
                              "dof_buffer[PAR_MB_NR][%d][%d]" %
                              (inl, dof, inl, dof - load_segment_start)))
                result.append(Line())
            return result

        from hedge.backends.cuda.tools import unroll

        def get_direct_tex_mat_mul_code():
            return (
                [POD(float_type, "fof%d" % inl) for inl in range(par.inline)] +
                [POD(float_type, "lm"), Line()] + unroll(
                    lambda j: [
                        Assign(
                            "fof%d" % inl,
                            "fp_tex1Dfetch(in_vector_tex, "
                            "GLOBAL_MB_PREIMG_DOF_BASE"
                            " + %(inl)d * ALIGNED_PREIMAGE_DOFS_PER_MB"
                            " + mb_el*PREIMAGE_DOFS_PER_EL+%(j)s)" % {
                                "j": j,
                                "inl": inl,
                                "row": "SEGMENT_DOF"
                            },
                        ) for inl in range(par.inline)
                    ] + [
                        Assign(
                            "lm",
                            "smem_matrix["
                            "%(row)s*MATRIX_COLUMNS + %(j)s]" % {
                                "j": j,
                                "row": "SEGMENT_DOF"
                            },
                        )
                    ] + [
                        S("result%(inl)d += fof%(inl)d*lm" % {"inl": inl})
                        for inl in range(par.inline)
                    ],
                    total_number=self.plan.preimage_dofs_per_el,
                    max_unroll=self.plan.max_unroll) + [Line()])

        def get_mat_mul_code(el_fetch_count):
            if el_fetch_count == 1:
                return get_batched_fetch_mat_mul_code(el_fetch_count)
            else:
                return get_direct_tex_mat_mul_code()

        def mat_mul_outer_loop(fetch_count):
            if with_scaling:
                inv_jac_multiplier = (
                    "fp_tex1Dfetch(scaling_tex,"
                    "(GLOBAL_MB_NR + %(inl)d)*MB_EL_COUNT + mb_el)")
            else:
                inv_jac_multiplier = "1"

            write_condition = "MB_DOF < DOFS_PER_EL*MB_EL_COUNT"
            if self.with_index_check:
                write_condition += " && GLOBAL_MB_NR < microblock_count"
            return For(
                "unsigned short seq_mb_number = 0",
                "seq_mb_number < SEQ_MB_COUNT", "++seq_mb_number",
                Block([
                    Initializer(POD(float_type, "result%d" % inl), 0)
                    for inl in range(par.inline)
                ] + [Line()] + get_mat_mul_code(fetch_count) + [
                    If(
                        write_condition,
                        Block([
                            Assign(
                                "out_vector[GLOBAL_MB_DOF_BASE"
                                " + %d*ALIGNED_DOFS_PER_MB"
                                " + MB_DOF]" % inl, "result%d * %s" %
                                (inl, (inv_jac_multiplier % {
                                    "inl": inl
                                }))) for inl in range(par.inline)
                        ]))
                ]))

        if self.plan.use_prefetch_branch:
            from cgen import make_multiple_ifs
            f_body.append(
                make_multiple_ifs([
                    ("segment_el_count == %d" % fetch_count,
                     mat_mul_outer_loop(fetch_count)) for fetch_count in range(
                         1,
                         self.plan.max_elements_touched_by_segment() + 1)
                ]))
        else:
            f_body.append(mat_mul_outer_loop(0))

        # finish off ----------------------------------------------------------
        cmod.append(FunctionBody(f_decl, f_body))

        if not for_benchmark and "cuda_dump_kernels" in discr.debug:
            from hedge.tools import open_unique_debug_file
            open_unique_debug_file(self.plan.debug_name,
                                   ".cu").write(str(cmod))

        mod = SourceModule(
            cmod,
            keep="cuda_keep_kernels" in discr.debug,
            #options=["--maxrregcount=12"]
        )

        func = mod.get_function("apply_el_local_mat_smem_mat")

        if self.plan.debug_name in discr.debug:
            print "%s: lmem=%d smem=%d regs=%d" % (
                self.plan.debug_name, func.local_size_bytes,
                func.shared_size_bytes, func.num_regs)

        in_vector_texref = mod.get_texref("in_vector_tex")
        texrefs = [in_vector_texref]

        if with_scaling:
            scaling_texref = mod.get_texref("scaling_tex")
            texrefs.append(scaling_texref)
        else:
            scaling_texref = None

        func.prepare("PPPI",
                     block=(self.plan.segment_size,
                            self.plan.parallelism.parallel, 1),
                     texrefs=texrefs)

        return func, in_vector_texref, scaling_texref
Exemplo n.º 15
0
    def get_kernel(self, fdata, ilist_data, for_benchmark):
        from cgen.cuda import CudaShared, CudaGlobal
        from pycuda.tools import dtype_to_ctype

        discr = self.discr
        given = self.plan.given
        fplan = self.plan
        d = discr.dimensions
        dims = range(d)

        elgroup, = discr.element_groups

        float_type = given.float_type

        f_decl = CudaGlobal(
            FunctionDeclaration(Value("void", "apply_flux"), [
                Pointer(POD(float_type, "debugbuf")),
                Pointer(POD(numpy.uint8, "gmem_facedata")),
            ] + [
                Pointer(POD(float_type, "gmem_fluxes_on_faces%d" % flux_nr))
                for flux_nr in range(len(self.fluxes))
            ]))

        cmod = Module()
        cmod.append(Include("pycuda-helpers.hpp"))

        for dep_expr in self.all_deps:
            cmod.extend([
                Value(
                    "texture<%s, 1, cudaReadModeElementType>" %
                    dtype_to_ctype(float_type, with_fp_tex_hack=True),
                    "field%d_tex" % self.dep_to_index[dep_expr])
            ])

        if fplan.flux_count != len(self.fluxes):
            from warnings import warn
            warn(
                "Flux count in flux execution plan different from actual flux count.\n"
                "You may want to specify the tune_for= kwarg in the Discretization\n"
                "constructor.")

        cmod.extend([
            Line(),
            Typedef(POD(float_type, "value_type")),
            Line(),
            flux_header_struct(float_type, discr.dimensions),
            Line(),
            face_pair_struct(float_type, discr.dimensions),
            Line(),
            Define("DIMENSIONS", discr.dimensions),
            Define("DOFS_PER_FACE", fplan.dofs_per_face),
            Define("THREADS_PER_FACE", fplan.threads_per_face()),
            Line(),
            Define("CONCURRENT_FACES", fplan.parallel_faces),
            Define("BLOCK_MB_COUNT", fplan.mbs_per_block),
            Line(),
            Define("FACEDOF_NR", "threadIdx.x"),
            Define("BLOCK_FACE", "threadIdx.y"),
            Line(),
            Define("FLUX_COUNT", len(self.fluxes)),
            Line(),
            Define("THREAD_NUM", "(FACEDOF_NR + BLOCK_FACE*THREADS_PER_FACE)"),
            Define("THREAD_COUNT", "(THREADS_PER_FACE*CONCURRENT_FACES)"),
            Define(
                "COALESCING_THREAD_COUNT",
                "(THREAD_COUNT < 0x10 ? THREAD_COUNT : THREAD_COUNT & ~0xf)"),
            Line(),
            Define("DATA_BLOCK_SIZE", fdata.block_bytes),
            Define("ALIGNED_FACE_DOFS_PER_MB",
                   fplan.aligned_face_dofs_per_microblock()),
            Define("ALIGNED_FACE_DOFS_PER_BLOCK",
                   "(ALIGNED_FACE_DOFS_PER_MB*BLOCK_MB_COUNT)"),
            Line(),
            Define("FOF_BLOCK_BASE",
                   "(blockIdx.x*ALIGNED_FACE_DOFS_PER_BLOCK)"),
            Line(),
        ] + ilist_data.code + [
            Line(),
            Value("texture<index_list_entry_t, 1, cudaReadModeElementType>",
                  "tex_index_lists"),
            Line(),
            fdata.struct,
            Line(),
            CudaShared(Value("flux_data", "data")),
        ])

        if not fplan.direct_store:
            cmod.extend([
                CudaShared(
                    ArrayOf(
                        ArrayOf(POD(float_type, "smem_fluxes_on_faces"),
                                "FLUX_COUNT"),
                        "ALIGNED_FACE_DOFS_PER_MB*BLOCK_MB_COUNT")),
                Line(),
            ])

        S = Statement
        f_body = Block()

        from hedge.backends.cuda.tools import get_load_code

        f_body.extend(
            get_load_code(dest="&data",
                          base="gmem_facedata + blockIdx.x*DATA_BLOCK_SIZE",
                          bytes="sizeof(flux_data)",
                          descr="load face_pair data") +
            [S("__syncthreads()"), Line()])

        def get_flux_code(flux_writer):
            flux_code = Block([])

            flux_code.extend([
                Initializer(Pointer(Value("face_pair", "fpair")),
                            "data.facepairs+fpair_nr"),
                Initializer(
                    MaybeUnused(POD(numpy.uint32, "a_index")),
                    "fpair->a_base + tex1Dfetch(tex_index_lists, "
                    "fpair->a_ilist_index + FACEDOF_NR)"),
                Initializer(
                    MaybeUnused(POD(numpy.uint32, "b_index")),
                    "fpair->b_base + tex1Dfetch(tex_index_lists, "
                    "fpair->b_ilist_index + FACEDOF_NR)"),
                Line(),
                flux_writer(),
                Line(),
                S("fpair_nr += CONCURRENT_FACES")
            ])

            return flux_code

        flux_computation = Block([
            Comment("fluxes for dual-sided (intra-block) interior face pairs"),
            While("fpair_nr < data.header.same_facepairs_end",
                  get_flux_code(lambda: self.write_interior_flux_code(True))),
            Line(),
            Comment("work around nvcc assertion failure"),
            S("fpair_nr+=1"),
            S("fpair_nr-=1"),
            Line(),
            Comment(
                "fluxes for single-sided (inter-block) interior face pairs"),
            While("fpair_nr < data.header.diff_facepairs_end",
                  get_flux_code(lambda: self.write_interior_flux_code(False))),
            Line(),
            Comment("fluxes for single-sided boundary face pairs"),
            While(
                "fpair_nr < data.header.bdry_facepairs_end",
                get_flux_code(
                    lambda: self.write_boundary_flux_code(for_benchmark))),
        ])

        f_body.extend_log_block("compute the fluxes", [
            Initializer(POD(numpy.uint32, "fpair_nr"), "BLOCK_FACE"),
            If("FACEDOF_NR < DOFS_PER_FACE", flux_computation)
        ])

        if not fplan.direct_store:
            f_body.extend([Line(), S("__syncthreads()"), Line()])

            f_body.extend_log_block(
                "store fluxes",
                [
                    #Assign("debugbuf[blockIdx.x]", "FOF_BLOCK_BASE"),
                    #Assign("debugbuf[0]", "FOF_BLOCK_BASE"),
                    #Assign("debugbuf[0]", "sizeof(face_pair)"),
                    For(
                        "unsigned word_nr = THREAD_NUM",
                        "word_nr < ALIGNED_FACE_DOFS_PER_MB*BLOCK_MB_COUNT",
                        "word_nr += COALESCING_THREAD_COUNT",
                        Block([
                            Assign(
                                "gmem_fluxes_on_faces%d[FOF_BLOCK_BASE+word_nr]"
                                % flux_nr,
                                "smem_fluxes_on_faces[%d][word_nr]" % flux_nr)
                            for flux_nr in range(len(self.fluxes))
                        ]
                              #+[If("isnan(smem_fluxes_on_faces[%d][word_nr])" % flux_nr,
                              #Block([
                              #Assign("debugbuf[blockIdx.x]", "word_nr"),
                              #])
                              #)
                              #for flux_nr in range(len(self.fluxes))]
                              ))
                ])
        if False:
            f_body.extend([
                Assign("debugbuf[blockIdx.x*96+32+BLOCK_FACE*32+threadIdx.x]",
                       "fpair_nr"),
                Assign("debugbuf[blockIdx.x*96+16]",
                       "data.header.same_facepairs_end"),
                Assign("debugbuf[blockIdx.x*96+17]",
                       "data.header.diff_facepairs_end"),
                Assign("debugbuf[blockIdx.x*96+18]",
                       "data.header.bdry_facepairs_end"),
            ])

        # finish off ----------------------------------------------------------
        cmod.append(FunctionBody(f_decl, f_body))

        if not for_benchmark and "cuda_dump_kernels" in discr.debug:
            from hedge.tools import open_unique_debug_file
            open_unique_debug_file("flux_gather", ".cu").write(str(cmod))

        #from pycuda.tools import allow_user_edit
        mod = SourceModule(
            #allow_user_edit(cmod, "kernel.cu", "the flux kernel"),
            cmod,
            keep="cuda_keep_kernels" in discr.debug)
        expr_to_texture_map = dict(
            (dep_expr,
             mod.get_texref("field%d_tex" % self.dep_to_index[dep_expr]))
            for dep_expr in self.all_deps)

        index_list_texref = mod.get_texref("tex_index_lists")
        index_list_texref.set_address(ilist_data.device_memory,
                                      ilist_data.bytes)
        index_list_texref.set_format(
            cuda.dtype_to_array_format(ilist_data.type), 1)
        index_list_texref.set_flags(cuda.TRSF_READ_AS_INTEGER)

        func = mod.get_function("apply_flux")
        block = (fplan.threads_per_face(), fplan.parallel_faces, 1)
        func.prepare(
            (2 + len(self.fluxes)) * "P",
            texrefs=expr_to_texture_map.values() + [index_list_texref])

        if "cuda_flux" in discr.debug:
            print "flux: lmem=%d smem=%d regs=%d" % (
                func.local_size_bytes, func.shared_size_bytes, func.num_regs)

        return block, func, expr_to_texture_map
Exemplo n.º 16
0
    def get_kernel(self, diff_op, elgroup, for_benchmark=False):
        from cgen import \
                Pointer, POD, Value, ArrayOf, Const, \
                Module, FunctionDeclaration, FunctionBody, Block, \
                Comment, Line, Define, Include, \
                Initializer, If, For, Statement, Assign

        from pycuda.tools import dtype_to_ctype
        from cgen.cuda import CudaShared, CudaGlobal

        discr = self.discr
        d = discr.dimensions
        dims = range(d)
        plan = self.plan
        given = plan.given

        elgroup, = discr.element_groups
        float_type = given.float_type

        f_decl = CudaGlobal(FunctionDeclaration(Value("void", "apply_diff_mat_smem"),
            [Pointer(POD(float_type, "debugbuf")), Pointer(POD(float_type, "field")), ]
            + [Pointer(POD(float_type, "drst%d_global" % i)) for i in dims]
            ))

        par = plan.parallelism

        cmod = Module([
                Include("pycuda-helpers.hpp"),
                ])

        if float_type == numpy.float64:
            cmod.append(Value("texture<fp_tex_double, 1, cudaReadModeElementType>",
                    "diff_rst_mat_tex"))
        elif float_type == numpy.float32:
            rst_channels = given.devdata.make_valid_tex_channel_count(d)
            cmod.append(Value("texture<float%d, 1, cudaReadModeElementType>"
                    % rst_channels, "diff_rst_mat_tex"))
        else:
            raise ValueError("unsupported float type: %s" % float_type)

        # only preimage size variation is supported here
        assert plan.image_dofs_per_el == given.dofs_per_el()
        assert plan.aligned_image_dofs_per_microblock == given.microblock.aligned_floats

        # FIXME: aligned_image_dofs_per_microblock must be divisible
        # by this, therefore hardcoding for now.
        chunk_size = 16

        cmod.extend([
                Line(),
                Define("DIMENSIONS", discr.dimensions),

                Define("IMAGE_DOFS_PER_EL", plan.image_dofs_per_el),
                Define("PREIMAGE_DOFS_PER_EL", plan.preimage_dofs_per_el),
                Define("ALIGNED_IMAGE_DOFS_PER_MB", plan.aligned_image_dofs_per_microblock),
                Define("ALIGNED_PREIMAGE_DOFS_PER_MB", plan.aligned_preimage_dofs_per_microblock),
                Define("ELS_PER_MB", given.microblock.elements),
                Define("IMAGE_DOFS_PER_MB", "(IMAGE_DOFS_PER_EL*ELS_PER_MB)"),
                Line(),
                Define("CHUNK_SIZE", chunk_size),
                Define("CHUNK_DOF", "threadIdx.x"),
                Define("PAR_MB_NR", "threadIdx.y"),
                Define("CHUNK_NR", "threadIdx.z"),
                Define("IMAGE_MB_DOF", "(CHUNK_NR*CHUNK_SIZE+CHUNK_DOF)"),
                Define("IMAGE_EL_DOF", "(IMAGE_MB_DOF - mb_el*IMAGE_DOFS_PER_EL)"),
                Line(),
                Define("MACROBLOCK_NR", "blockIdx.x"),
                Line(),
                Define("PAR_MB_COUNT", par.parallel),
                Define("INLINE_MB_COUNT", par.inline),
                Define("SEQ_MB_COUNT", par.serial),
                Line(),
                Define("GLOBAL_MB_NR_BASE",
                    "(MACROBLOCK_NR*PAR_MB_COUNT*INLINE_MB_COUNT*SEQ_MB_COUNT)"),
                Define("GLOBAL_MB_NR",
                    "(GLOBAL_MB_NR_BASE"
                    "+ (seq_mb_number*PAR_MB_COUNT + PAR_MB_NR)*INLINE_MB_COUNT)"),
                Define("GLOBAL_MB_IMAGE_DOF_BASE", "(GLOBAL_MB_NR*ALIGNED_IMAGE_DOFS_PER_MB)"),
                Define("GLOBAL_MB_PREIMAGE_DOF_BASE", "(GLOBAL_MB_NR*ALIGNED_PREIMAGE_DOFS_PER_MB)"),
                Line(),
                CudaShared(
                    ArrayOf(
                        ArrayOf(
                            ArrayOf(
                                POD(float_type, "smem_field"),
                                "PAR_MB_COUNT"),
                            "INLINE_MB_COUNT"),
                        "ALIGNED_PREIMAGE_DOFS_PER_MB")),
                Line(),
                ])

        S = Statement
        f_body = Block([
            Initializer(Const(POD(numpy.uint16, "mb_el")),
                "IMAGE_MB_DOF / IMAGE_DOFS_PER_EL"),
            Line(),
            ])

        # ---------------------------------------------------------------------
        def get_load_code():
            mb_img_dofs = plan.aligned_image_dofs_per_microblock
            mb_preimg_dofs = plan.aligned_preimage_dofs_per_microblock
            preimg_dofs_over_dofs = (mb_preimg_dofs+mb_img_dofs-1) // mb_img_dofs

            load_code = []
            store_code = []

            var_num = 0
            for load_block in range(preimg_dofs_over_dofs):
                for inl in range(par.inline):
                    # load and store are split for better pipelining
                    # compiler can't figure that out because of branch

                    var = "tmp%d" % var_num
                    var_num += 1
                    load_code.append(POD(float_type, var))

                    block_addr = "%d * ALIGNED_IMAGE_DOFS_PER_MB + IMAGE_MB_DOF" % load_block
                    load_instr = Assign(var,
                        "field[GLOBAL_MB_PREIMAGE_DOF_BASE"
                        " + %d*ALIGNED_PREIMAGE_DOFS_PER_MB"
                        " + %s]" % (inl, block_addr))
                    store_instr = Assign(
                            "smem_field[PAR_MB_NR][%d][%s]" % (inl, block_addr),
                            var
                            )
                    if (load_block+1)*mb_img_dofs >= mb_preimg_dofs:
                        cond = "%s < ALIGNED_PREIMAGE_DOFS_PER_MB" % block_addr
                        load_instr = If(cond, load_instr)
                        store_instr = If(cond, store_instr)

                    load_code.append(load_instr)
                    store_code.append(store_instr)
            return Block(load_code + [Line()] + store_code)

        def get_scalar_diff_code():
            code = []
            for inl in range(par.inline):
                for axis in dims:
                    code.append(
                        Initializer(POD(float_type, "d%drst%d" % (inl, axis)), 0))

            code.append(Line())

            tex_channels = ["x", "y", "z", "w"]

            store_code = Block()
            for inl in range(par.inline):
                for rst_axis in dims:
                    store_code.append(Assign(
                        "drst%d_global[GLOBAL_MB_IMAGE_DOF_BASE + "
                        "%d*ALIGNED_IMAGE_DOFS_PER_MB + IMAGE_MB_DOF]"
                        % (rst_axis, inl),
                        "d%drst%d" % (inl, rst_axis)
                        ))

            from hedge.backends.cuda.tools import unroll
            code.extend([
                Comment("everybody needs to be done with the old data"),
                S("__syncthreads()"),
                Line(),
                get_load_code(),
                Line(),
                Comment("all the new data must be loaded"),
                S("__syncthreads()"),
                Line(),
                ])

            if float_type == numpy.float32:
                code.append(Value("float%d" % rst_channels, "dmat_entries"))

            code.extend([
                POD(float_type, "field_value%d" % inl)
                for inl in range(par.inline)
                ]+[Line()])

            def unroll_body(j):
                result = [
                    Assign("field_value%d" % inl,
                        "smem_field[PAR_MB_NR][%d][mb_el*PREIMAGE_DOFS_PER_EL+%s]" % (inl, j))
                    for inl in range(par.inline)
                    ]

                if float_type == numpy.float32:
                    result.append(Assign("dmat_entries",
                        "tex1Dfetch(diff_rst_mat_tex, IMAGE_EL_DOF + %s*IMAGE_DOFS_PER_EL)" % j))
                    result.extend(
                        S("d%drst%d += dmat_entries.%s * field_value%d"
                            % (inl, axis, tex_channels[axis], inl))
                        for inl in range(par.inline)
                        for axis in dims)
                elif float_type == numpy.float64:
                    result.extend(
                        S("d%(inl)drst%(axis)d += "
                            "fp_tex1Dfetch(diff_rst_mat_tex, %(axis)d "
                            "+ DIMENSIONS*(IMAGE_EL_DOF + %(j)d*IMAGE_DOFS_PER_EL))"
                            "* field_value%(inl)d" % {
                            "inl": inl,
                            "axis": axis,
                            "j": j
                            })
                        for inl in range(par.inline)
                        for axis in dims)
                else:
                    assert False

                return result

            code.append(If("IMAGE_MB_DOF < IMAGE_DOFS_PER_MB", Block(unroll(unroll_body,
                    total_number=plan.preimage_dofs_per_el)
                    +[store_code])))

            return code

        f_body.extend([
            For("unsigned short seq_mb_number = 0",
                "seq_mb_number < SEQ_MB_COUNT",
                "++seq_mb_number",
                Block(get_scalar_diff_code())
                )
            ])

        # finish off ----------------------------------------------------------
        cmod.append(FunctionBody(f_decl, f_body))

        if not for_benchmark and "cuda_dump_kernels" in discr.debug:
            from hedge.tools import open_unique_debug_file
            open_unique_debug_file("diff", ".cu").write(str(cmod))

        mod = SourceModule(cmod,
                keep="cuda_keep_kernels" in discr.debug,
                #options=["--maxrregcount=16"]
                )

        func = mod.get_function("apply_diff_mat_smem")

        if "cuda_diff" in discr.debug:
            print "diff: lmem=%d smem=%d regs=%d" % (
                    func.local_size_bytes,
                    func.shared_size_bytes,
                    func.registers)

        diff_rst_mat_texref = mod.get_texref("diff_rst_mat_tex")
        gpu_diffmats = self.gpu_diffmats(diff_op, elgroup)

        if given.float_type == numpy.float32:
            gpu_diffmats.bind_to_texref_ext(diff_rst_mat_texref, rst_channels)
        elif given.float_type == numpy.float64:
            gpu_diffmats.bind_to_texref_ext(diff_rst_mat_texref,
                    allow_double_hack=True)
        else:
            assert False

        assert given.microblock.aligned_floats % chunk_size == 0
        block = (
                chunk_size,
                plan.parallelism.parallel,
                given.microblock.aligned_floats//chunk_size)

        func.prepare(
                ["PP"] + discr.dimensions*["P"],
                texrefs=[diff_rst_mat_texref])

        return block, func
Exemplo n.º 17
0
    def create_native(self):
        from cgen import (ArrayOf, POD, Block, For, Statement, Struct)
        from cgen import dtype_to_ctype
        import numpy

        members = []
        code = []

        for pk, pv in config.parameters.iteritems():
            if isinstance(pv, int):
                members.append(POD(numpy.int, pk))
                code.append(
                    Statement("params.%s = extract<%s>(cppdict[\"%s\"])" %
                              (pk, dtype_to_ctype(numpy.int), pk)))
            elif isinstance(pv, float):
                members.append(POD(numpy.float64, pk))
                code.append(
                    Statement("params.%s = extract<%s>(cppdict[\"%s\"])" %
                              (pk, dtype_to_ctype(numpy.float64), pk)))
            elif isinstance(pv, list):
                if isinstance(pv[0], int):
                    members.append(ArrayOf(POD(numpy.int, pk), len(pv)))
                    code.append(
                        Block([
                            Statement("list v = extract<%s>(cppdict[\"%s\"])" %
                                      (list.__name__, pk)),
                            For(
                                "unsigned int i  = 0", "i<len(v)", "++i",
                                Statement("params.%s[i] = extract<%s>(v[i])" %
                                          (pk, dtype_to_ctype(numpy.int)))),
                        ]))
                elif isinstance(pv[0], float):
                    members.append(ArrayOf(POD(numpy.float64, pk), len(pv)))
                    code.append(
                        Block([
                            Statement("list v = extract<%s>(cppdict[\"%s\"])" %
                                      (list.__name__, pk)),
                            For(
                                "unsigned int i  = 0", "i < len(v)", "++i",
                                Block([
                                    Statement(
                                        "params.%s[i] = extract<%s>(v[i])" %
                                        (pk, dtype_to_ctype(numpy.float64))),
                                    Statement(
                                        "//std::cout << params.%s[i] << std::endl"
                                        % (pk))
                                ])),
                        ]))

        mystruct = Struct('Parameters', members)
        mycode = Block(code)

        # print mystruct
        # print mycode

        from jinja2 import Template

        tpl = Template("""
#include <boost/python.hpp>
#include <boost/python/object.hpp>
#include <boost/python/extract.hpp>
#include <boost/python/list.hpp>
#include <boost/python/dict.hpp>
#include <boost/python/str.hpp>
#include <stdexcept>
#include <iostream>

{{my_struct}}

Parameters params;

void CopyDictionary(boost::python::object pydict)
{
    using namespace boost::python;

    extract< dict > cppdict_ext(pydict);
    if(!cppdict_ext.check()){
        throw std::runtime_error(
                    "PassObj::pass_dict: type error: not a python dict.");
    }

    dict cppdict = cppdict_ext();
    list keylist = cppdict.keys();

    {{my_extractor}}


}

BOOST_PYTHON_MODULE({{my_module}})
{
   boost::python::def("copy_dict", &CopyDictionary);
}
        """)
        rendered_tpl = tpl.render(my_module="NativeParameters",
                                  my_extractor=mycode,
                                  my_struct=mystruct)

        # print rendered_tpl

        from codepy.toolchain import NVCCToolchain
        import codepy.toolchain

        kwargs = codepy.toolchain._guess_toolchain_kwargs_from_python_config()
        # print kwargs
        kwargs["cc"] = "nvcc"
        # kwargs["cflags"]=["-m64","-x","cu","-Xcompiler","-fPIC","-ccbin","/opt/local/bin/g++-mp-4.4"]
        kwargs["cflags"] = ["-m64", "-x", "cu", "-Xcompiler", "-fPIC"]
        kwargs["include_dirs"].append("/usr/local/cuda/include")
        kwargs["defines"] = []
        kwargs["ldflags"] = ["-shared"]
        # kwargs["libraries"]=["python2.7"]
        kwargs["libraries"] = ["python2.6"]
        print kwargs
        toolchain = NVCCToolchain(**kwargs)

        from codepy.libraries import add_boost_python
        add_boost_python(toolchain)

        from codepy.jit import extension_from_string
        mymod = extension_from_string(toolchain, "NativeParameters",
                                      rendered_tpl)

        mymod.copy_dict(config.parameters)
Exemplo n.º 18
0
from cgen import FunctionBody, \
        FunctionDeclaration, POD, Value, \
        Pointer, Module, Block, Initializer, Assign, Const
from cgen.opencl import CLKernel, CLGlobal, \
        CLRequiredWorkGroupSize

mod = Module([
    FunctionBody(
        CLKernel(
            CLRequiredWorkGroupSize(
                (local_size, ),
                FunctionDeclaration(Value("void", "add"),
                                    arg_decls=[
                                        CLGlobal(
                                            Pointer(Const(POD(dtype, name))))
                                        for name in ["tgt", "op1", "op2"]
                                    ]))),
        Block([
            Initializer(
                POD(numpy.int32,
                    "idx"), "get_local_id(0) + %d * get_group_id(0)" %
                (local_size * thread_strides))
        ] + [
            Assign(
                "tgt[idx+%d]" % (o * local_size), "op1[idx+%d] + op2[idx+%d]" %
                (o * local_size, o * local_size))
            for o in range(thread_strides)
        ]))
])
Exemplo n.º 19
0
def get_boundary_flux_mod(fluxes, fvi, discr, dtype):
    from cgen import \
            FunctionDeclaration, FunctionBody, Typedef, Struct, \
            Const, Reference, Value, POD, MaybeUnused, \
            Statement, Include, Line, Block, Initializer, Assign, \
            CustomLoop, For

    from pytools import to_uncomplex_dtype, flatten

    from codepy.bpl import BoostPythonModule
    mod = BoostPythonModule()

    mod.add_to_preamble([
        Include("cstdlib"),
        Include("algorithm"),
        Line(),
        Include("boost/foreach.hpp"),
        Line(),
        Include("hedge/face_operators.hpp"),
        ])

    S = Statement
    mod.add_to_module([
        S("using namespace hedge"),
        S("using namespace pyublas"),
        Line(),
        Typedef(POD(dtype, "value_type")),
        Typedef(POD(to_uncomplex_dtype(dtype), "uncomplex_type")),
        ])

    arg_struct = Struct("arg_struct", [
        Value("numpy_array<value_type>", "flux%d_on_faces" % i)
        for i in range(len(fluxes))
        ]+[
        Value("numpy_array<value_type>", arg_name)
        for arg_name in fvi.arg_names
        ])

    mod.add_struct(arg_struct, "ArgStruct")
    mod.add_to_module([Line()])

    fdecl = FunctionDeclaration(
                Value("void", "gather_flux"),
                [
                    Const(Reference(Value("face_group<face_pair<straight_face> >" , "fg"))),
                    Reference(Value("arg_struct", "args"))
                    ])

    from pymbolic.mapper.stringifier import PREC_PRODUCT

    def gen_flux_code():
        f2cm = FluxToCodeMapper()

        result = [
                Assign("fof%d_it[loc_fof_base+i]" % flux_idx,
                    "uncomplex_type(fp.int_side.face_jacobian) * " +
                    flux_to_code(f2cm, False, flux_idx, fvi, flux.op.flux, PREC_PRODUCT))
                for flux_idx, flux in enumerate(fluxes)
                ]

        return [
            Initializer(Value("value_type", cse_name), cse_str)
            for cse_name, cse_str in f2cm.cse_name_list] + result

    fbody = Block([
        Initializer(
            Const(Value("numpy_array<value_type>::iterator", "fof%d_it" % i)),
            "args.flux%d_on_faces.begin()" % i)
        for i in range(len(fluxes))
        ]+[
        Initializer(
            Const(Value("numpy_array<value_type>::const_iterator",
                "%s_it" % arg_name)),
            "args.%s.begin()" % arg_name)
        for arg_name in fvi.arg_names
        ]+[
        Line(),
        CustomLoop("BOOST_FOREACH(const face_pair<straight_face> &fp, fg.face_pairs)", Block(
            list(flatten([
            Initializer(Value("node_number_t", "%s_ebi" % where),
                "fp.%s.el_base_index" % where),
            Initializer(Value("index_lists_t::const_iterator", "%s_idx_list" % where),
                "fg.index_list(fp.%s.face_index_list_number)" % where),
            Line(),
            ]
            for where in ["int_side", "ext_side"]
            ))+[
            Line(),
            Initializer(Value("node_number_t", "loc_fof_base"),
                "fg.face_length()*(fp.%(where)s.local_el_number*fg.face_count"
                " + fp.%(where)s.face_id)" % {"where": "int_side"}),
            Line(),
            For(
                "unsigned i = 0",
                "i < fg.face_length()",
                "++i",
                Block(
                    [
                    Initializer(MaybeUnused(
                        Value("node_number_t", "%s_idx" % where)),
                        "%(where)s_ebi + %(where)s_idx_list[i]"
                        % {"where": where})
                    for where in ["int_side", "ext_side"]
                    ]+gen_flux_code()
                    )
                )
            ]))
        ])

    mod.add_function(FunctionBody(fdecl, fbody))

    #print "----------------------------------------------------------------"
    #print mod.generate()
    #raw_input("[Enter]")

    return mod.compile(get_flux_toolchain(discr, fluxes))
Exemplo n.º 20
0
a_gpu = cuda.to_device(a)
b_gpu = cuda.to_device(b)
c_gpu = cuda.mem_alloc(a.nbytes)

from cgen import FunctionBody, \
        FunctionDeclaration, Typedef, POD, Value, \
        Pointer, Module, Block, Initializer, Assign
from cgen.cuda import CudaGlobal

mod = Module([
    FunctionBody(
        CudaGlobal(
            FunctionDeclaration(Value("void", "add"),
                                arg_decls=[
                                    Pointer(POD(dtype, name))
                                    for name in ["tgt", "op1", "op2"]
                                ])),
        Block([
            Initializer(
                POD(numpy.int32, "idx"), "threadIdx.x + %d*blockIdx.x" %
                (block_size * thread_strides)),
        ] + [
            Assign(
                "tgt[idx+%d]" % (o * block_size), "op1[idx+%d] + op2[idx+%d]" %
                (o * block_size, o * block_size))
            for o in range(thread_strides)
        ]))
])

mod = SourceModule(mod)
Exemplo n.º 21
0
def test_ptr_to_array():
    t2 = Pointer(Pointer(ArrayOf(POD(np.float32, "yyy"), 2)))
    assert str(t2) == "float **yyy[2];"
Exemplo n.º 22
0
 def get_cpu_extra_parameter_declarators(self):
     from cgen import Value, POD
     return [
             Value("numpy_array<npy_uint32>", "mode_degrees"),
             POD(numpy.uint32, "max_degree")]
Exemplo n.º 23
0
    def make_diff(self, elgroup, dtype, shape):
        """
        :param shape: If non-square, the resulting code takes two element_ranges
          arguments and supports non-square matrices.
        """
        from hedge._internal import UniformElementRanges
        assert isinstance(elgroup.ranges, UniformElementRanges)

        ldis = elgroup.local_discretization
        discr = self.discr
        from cgen import (
                FunctionDeclaration, FunctionBody, Typedef,
                Const, Reference, Value, POD,
                Statement, Include, Line, Block, Initializer, Assign,
                For, If,
                Define)

        from pytools import to_uncomplex_dtype

        from codepy.bpl import BoostPythonModule
        mod = BoostPythonModule()

        # {{{ preamble
        S = Statement
        mod.add_to_preamble([
            Include("hedge/volume_operators.hpp"),
            Include("boost/foreach.hpp"),
            ])

        mod.add_to_module([
            S("namespace ublas = boost::numeric::ublas"),
            S("using namespace hedge"),
            S("using namespace pyublas"),
            Line(),
            Define("ROW_COUNT", shape[0]),
            Define("COL_COUNT", shape[1]),
            Define("DIMENSIONS", discr.dimensions),
            Line(),
            Typedef(POD(dtype, "value_type")),
            Typedef(POD(to_uncomplex_dtype(dtype), "uncomplex_type")),
            ])

        fdecl = FunctionDeclaration(
                    Value("void", "diff"),
                    [
                    Const(Reference(Value("uniform_element_ranges", "from_ers"))),
                    Const(Reference(Value("uniform_element_ranges", "to_ers"))),
                    Value("numpy_array<value_type>", "field")
                    ]+[
                    Value("ublas::matrix<uncomplex_type>", "diffmat_rst%d" % rst)
                    for rst in range(discr.dimensions)
                    ]+[
                    Value("numpy_array<value_type>", "result%d" % i)
                    for i in range(discr.dimensions)
                    ]
                    )
        # }}}

        # {{{ set-up
        def make_it(name, is_const=True, tpname="value_type"):
            if is_const:
                const = "const_"
            else:
                const = ""

            return Initializer(
                Value("numpy_array<%s>::%siterator" % (tpname, const), name+"_it"),
                "%s.begin()" % name)

        fbody = Block([
            If("ROW_COUNT != diffmat_rst%d.size1()" % i,
                S('throw(std::runtime_error("unexpected matrix size"))'))
            for i in range(discr.dimensions)
            ] + [
            If("COL_COUNT != diffmat_rst%d.size2()" % i,
                S('throw(std::runtime_error("unexpected matrix size"))'))
            for i in range(discr.dimensions) 
            ]+[
            If("ROW_COUNT != to_ers.el_size()",
                S('throw(std::runtime_error("unsupported image element size"))')),
            If("COL_COUNT != from_ers.el_size()",
                S('throw(std::runtime_error("unsupported preimage element size"))')),
            If("from_ers.size() != to_ers.size()",
                S('throw(std::runtime_error("image and preimage element groups '
                    'do nothave the same element count"))')),
            Line(),
            make_it("field"),
            ]+[
            make_it("result%d" % i, is_const=False)
            for i in range(discr.dimensions)
            ]+[
            Line(),
        # }}}

        # {{{ computation
            For("element_number_t eg_el_nr = 0",
                "eg_el_nr < to_ers.size()",
                "++eg_el_nr",
                Block([
                    Initializer(
                        Value("node_number_t", "from_el_base"),
                        "from_ers.start() + eg_el_nr*COL_COUNT"),
                    Initializer(
                        Value("node_number_t", "to_el_base"),
                        "to_ers.start() + eg_el_nr*ROW_COUNT"),
                    Line(),
                    For("unsigned i = 0",
                        "i < ROW_COUNT",
                        "++i",
                        Block([
                            Initializer(Value("value_type", "drst_%d" % rst), 0)
                            for rst in range(discr.dimensions)
                            ]+[
                            Line(),
                            ]+[
                            For("unsigned j = 0",
                                "j < COL_COUNT",
                                "++j",
                                Block([
                                    S("drst_%(rst)d += "
                                        "diffmat_rst%(rst)d(i, j)*field_it[from_el_base+j]"
                                        % {"rst":rst})
                                    for rst in range(discr.dimensions)
                                    ])
                                ),
                            Line(),
                            ]+[
                            Assign("result%d_it[to_el_base+i]" % rst,
                                "drst_%d" % rst)
                            for rst in range(discr.dimensions)
                            ])
                        )
                    ])
                )
            ])
        # }}}

        # {{{ compilation
        mod.add_function(FunctionBody(fdecl, fbody))

        #print "----------------------------------------------------------------"
        #print mod.generate()
        #raw_input()

        compiled_func = mod.compile(self.discr.toolchain).diff

        if self.discr.instrumented:
            from hedge.tools import time_count_flop

            compiled_func = time_count_flop(compiled_func,
                    discr.diff_timer, discr.diff_counter,
                    discr.diff_flop_counter,
                    flops=discr.dimensions*(
                        2 # mul+add
                        * ldis.node_count() * len(elgroup.members)
                        * ldis.node_count()
                        +
                        2 * discr.dimensions
                        * len(elgroup.members) * ldis.node_count()),
                    increment=discr.dimensions)

        return compiled_func