Beispiel #1
0
    def map_IfThen(self, node):
        current_cond = self.transform_expr(node.expr)

        blocks_and_conds = []
        else_block = []

        def end_block():
            if current_body:
                if current_cond is None:
                    else_block[:] = self.map_statement_list(current_body)
                else:
                    blocks_and_conds.append(
                        (current_cond,
                         cgen.block_if_necessary(
                             self.map_statement_list(current_body))))

            del current_body[:]

        from fparser.statements import Else, ElseIf
        i = 0
        current_body = []
        while i < len(node.content):
            c = node.content[i]
            if isinstance(c, ElseIf):
                end_block()
                current_cond = self.transform_expr(c.expr)
            elif isinstance(c, Else):
                end_block()
                current_cond = None
            else:
                current_body.append(c)

            i += 1
        end_block()

        def block_or_none(body):
            if not body:
                return None
            else:
                return cgen.block_if_necessary(body)

        return cgen.make_multiple_ifs(blocks_and_conds,
                                      block_or_none(else_block))
Beispiel #2
0
    def map_IfThen(self, node):
        current_cond = self.transform_expr(node.expr)

        blocks_and_conds = []
        else_block = []

        def end_block():
            if current_body:
                if current_cond is None:
                    else_block[:] = self.map_statement_list(current_body)
                else:
                    blocks_and_conds.append(
                            (current_cond, cgen.block_if_necessary(
                                self.map_statement_list(current_body))))

            del current_body[:]

        from fparser.statements import Else, ElseIf
        i = 0
        current_body = []
        while i < len(node.content):
            c = node.content[i]
            if isinstance(c, ElseIf):
                end_block()
                current_cond = self.transform_expr(c.expr)
            elif isinstance(c, Else):
                end_block()
                current_cond = None
            else:
                current_body.append(c)

            i += 1
        end_block()

        def block_or_none(body):
            if not body:
                return None
            else:
                return cgen.block_if_necessary(body)

        return cgen.make_multiple_ifs(
                blocks_and_conds,
                block_or_none(else_block))
    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
Beispiel #4
0
     c.Pointer(c.Value('double', 'ax')),
     c.Pointer(c.Value('double', 'bx')),
     c.Const(c.Pointer(c.Value('int', 'idx')))
 ]),
 c.Block([
     c.LineComment('Local variables'),
     c.Value('double', 'd_x, b_x, f_x, alfa_x'),
     c.Value('double', 'Lx'),
     c.Line(),
     c.Assign('Lx', 'CPML * dx'),
     c.LineComment('This sould be outside the kernel.'),
     c.Line(),
     c.make_multiple_ifs(
         [['idx[0] < 0',
           c.Assign('f_x', 'Lx - (idx[0] + CPML) * dx')],
          [
              'idx[0] > nx - 2 * CPML',
              c.Assign('f_x', 'dx * (idx[0] - nx + 2 * CPML)')
          ], ['', c.Assign('f_x', '0')]], 'last'),
     c.Line(),
     c.Assign('alfa_x',
              'M_PI * RICKER_PEAK_FREQUENCY * (Lx - f_x) / Lx'),
     c.Assign(
         'd_x',
         '-3.0 * log(0.00001) / (2.0 * Lx) * MAX_VELOCITY * (f_x / Lx) * (f_x / Lx)'
     ),
     c.Assign('b_x', 'exp(-dt * (d_x + alfa_x))'),
     c.Line(),
     c.Assign('ax[OPS_ACC0(0, 0)]', 'd_x * (b_x - 1) / (d_x + alfa_x)'),
     c.Assign('bx[OPS_ACC1(0, 0)]', 'exp(-dt * (d_x + alfa_x))')
 ])))
Beispiel #5
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