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submission 186593

rcmalli · python · License unknown

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Vendorable · source mirrored · license unknownView source →

No package. Vendor the mirrored source: 2307 lines, June 9 Researcher Reciprocity License v1.0.

submission_static.py
curl "https://kernelindex.com/api/v1/implementations/kernelbot-nvfp4-gemm-186593?include=source"
interfacepython
Compatibility
measured onNVIDIA B200
declared hardwareNVIDIA B200
architecturessm_100
dtypesfp8_e4m3, nvfp4

Benchmark evidence

1 measurement across 1 GPU, fastest first.

Operation / workload
Hardware
Latency
Rank
Observed
NVFP4 GEMMsuite of 3 cases
NVIDIA B200
11.1µs
#80 of 369
2025-12-20

Reported · How evidence levels are derived →

Source and license

sourceavailable
revision digestsha256:356447c9175b68525dfdf4133e22bc44b997c6a00a4fd399152764580638e925
license declaredunknown
license concludedunknown
authorsrcmalli
imported2026-08-15

Techniques

Extracted from the mirrored source by pattern, never inferred. Each row cites its line.

fused-epilogue- Computing epilogue subtile
mbarrierself.epilog_sync_barrier = pipeline.NamedBarrier(
persistent-kerneland architectural features specific to Blackwell GPUs with persistent tile scheduling and warp specialization.
shared-memoryself.smem_capacity = utils.get_smem_capacity_in_bytes("sm_100")
tcgen05tcgen05.CtaGroup.TWO if self.use_2cta_instrs else tcgen05.CtaGroup.ONE
warp-specializationab_pipeline_producer_group = pipeline.CooperativeGroup(pipeline.Agent.Thread)

Kernel source

submission_static.py2307 lines

from dataclasses import dataclass
from typing import Optional, Type, Tuple, Union

import cutlass
import cutlass.cute as cute
from cutlass.cute.nvgpu import cpasync, tcgen05
import cutlass.utils as utils
import cutlass.pipeline as pipeline
from cutlass.pipeline import pipeline_init_arrive, pipeline_init_wait
import cutlass.utils.blackwell_helpers as sm100_utils
import cutlass.utils.blockscaled_layout as blockscaled_utils
from cutlass.cute.runtime import make_ptr

from task import input_t, output_t

ab_dtype = cutlass.Float4E2M1FN
sf_dtype = cutlass.Float8E4M3FN
c_dtype = cutlass.Float16
sf_vec_size = 16



class Sm100BlockScaledPersistentDenseGemmKernel:
    """This class implements batched matrix multiplication (C = A x SFA x B x SFB) with support for various data types
    and architectural features specific to Blackwell GPUs with persistent tile scheduling and warp specialization.


    :note: In current version, A and B tensor must have the same data type
        - i.e., Float8E4M3FN for A and Float8E5M2 for B is not supported

    :note: Supported combinations of A/B data types, SF data typs and SF vector size:
        - MXF8: A/B: Float8E5M2/Float8E4M3FN + SF: Float8E8M0FNU + sf_vec_size: 32
        - MXF4: A/B: Float4E2M1FN + SF: Float8E8M0FNU + sf_vec_size: 32
        - NVF4: A/B: Float4E2M1FN + SF: Float8E8M0FNU/Float8E4M3FN + sf_vec_size: 16

    :note: Supported accumulator data types:
        - Float32

    :note: Supported C data types:
        - Float32
        - Float16/BFloat16
        - Float8E4M3FN/Float8E5M2
    :note: Constraints:
        - MMA tiler M must be 128 or 256 (use_2cta_instrs)
        - MMA tiler N must be 64/128/192/256
        - Cluster shape M must be multiple of 2 if Mma tiler M is 256
        - Cluster shape M/N must be positive and power of 2, total cluster size <= 16
        - Also, Cluster shape M/N must be <= 4 for scale factor multicasts due to limited size of scale factors

    Example:
        >>> gemm = Sm100BlockScaledPersistentDenseGemmKernel(
        ...     sf_vec_size=16,
        ...     mma_tiler_mn=(256, 128),
        ...     cluster_shape_mn=(2, 1)
        ... )
        >>> gemm(a_tensor, b_tensor, sfa_tensor, sfb_tensor, c_tensor, max_active_clusters)
    """

    def __init__(
        self,
        mma_tiler_mn: Tuple[int, int],
        cluster_shape_mn: Tuple[int, int],
        num_ab_stage: Optional[int] = None,
        num_c_stage: Optional[int] = None,
        mma_inst_tile_k: int = 4, 
    ):
        """Initializes the configuration for a Blackwell dense GEMM kernel.

        This configuration includes several key aspects:

        1.  MMA Instruction Settings (tcgen05):
            - acc_dtype: Data types for MMA accumulator, always set to Float32
            - sf_vec_size: Scalefactor A/B vector size.
            - mma_tiler_mn: The (M, N) shape of the MMA instruction tiler.

        2.  Cluster Shape:
            - cluster_shape_mn: The (ClusterM, ClusterN) shape of the CTA cluster.

        """

        self.acc_dtype = cutlass.Float32
        self.use_2cta_instrs = mma_tiler_mn[0] == 256
        self.cluster_shape_mn = cluster_shape_mn
        # K dimension is deferred in _setup_attributes
        self.mma_tiler = (*mma_tiler_mn, 1)
        self.num_ab_stage_override = num_ab_stage
        self.num_c_stage_override = num_c_stage
        self.mma_inst_tile_k = mma_inst_tile_k


        self.cta_group = (
            tcgen05.CtaGroup.TWO if self.use_2cta_instrs else tcgen05.CtaGroup.ONE
        )

        self.occupancy = 1
        # Set specialized warp ids
        self.epilog_warp_id = (
            0,
            1,
            2,
            3,
        )
        self.mma_warp_id = 4
        self.tma_warp_id = 5
        self.threads_per_cta = 32 * len(
            (self.mma_warp_id, self.tma_warp_id, *self.epilog_warp_id)
        )
        # Set barrier id for epilogue sync and tmem ptr sync
        self.epilog_sync_barrier = pipeline.NamedBarrier(
            barrier_id=1,
            num_threads=32 * len(self.epilog_warp_id),
        )
        self.tmem_alloc_barrier = pipeline.NamedBarrier(
            barrier_id=2,
            num_threads=32 * len((self.mma_warp_id, *self.epilog_warp_id)),
        )
        self.smem_capacity = utils.get_smem_capacity_in_bytes("sm_100")
        SM100_TMEM_CAPACITY_COLUMNS = 512
        self.num_tmem_alloc_cols = SM100_TMEM_CAPACITY_COLUMNS

    def _setup_attributes(self):
        """Set up configurations that are dependent on GEMM inputs

        This method configures various attributes based on the input tensor properties
        (data types, leading dimensions) and kernel settings:
        - Configuring tiled MMA
        - Computing MMA/cluster/tile shapes
        - Computing cluster layout
        - Computing multicast CTAs for A/B/SFA/SFB
        - Computing epilogue subtile
        - Setting up A/B/SFA/SFB/C stage counts in shared memory
        - Computing A/B/SFA/SFB/C shared memory layout
        """
        # Compute mma instruction shapes
        # (MMA_Tile_Shape_M, MMA_Tile_Shape_N, MMA_Inst_Shape_K)
        self.mma_inst_shape_mn = (
            self.mma_tiler[0],
            self.mma_tiler[1],
        )
        # (CTA_Tile_Shape_M, Round_Up(MMA_Tile_Shape_N, 128), MMA_Inst_Shape_K)
        self.mma_inst_shape_mn_sfb = (
            self.mma_inst_shape_mn[0] // (2 if self.use_2cta_instrs else 1),
            cute.round_up(self.mma_inst_shape_mn[1], 128),
        )

        tiled_mma = sm100_utils.make_blockscaled_trivial_tiled_mma(
            ab_dtype,
            self.a_major_mode,
            self.b_major_mode,
            sf_dtype,
            sf_vec_size,
            self.cta_group,
            self.mma_inst_shape_mn,
        )

        tiled_mma_sfb = sm100_utils.make_blockscaled_trivial_tiled_mma(
            ab_dtype,
            self.a_major_mode,
            self.b_major_mode,
            sf_dtype,
            sf_vec_size,
            cute.nvgpu.tcgen05.CtaGroup.ONE,
            self.mma_inst_shape_mn_sfb,
        )

        # Compute mma/cluster/tile shapes
        mma_inst_shape_k = cute.size(tiled_mma.shape_mnk, mode=[2])
        self.mma_tiler = (
            self.mma_inst_shape_mn[0],
            self.mma_inst_shape_mn[1],
            mma_inst_shape_k * self.mma_inst_tile_k,
        )
        self.mma_tiler_sfb = (
            self.mma_inst_shape_mn_sfb[0],
            self.mma_inst_shape_mn_sfb[1],
            mma_inst_shape_k * self.mma_inst_tile_k,
        )
        self.cta_tile_shape_mnk = (
            self.mma_tiler[0] // cute.size(tiled_mma.thr_id.shape),
            self.mma_tiler[1],
            self.mma_tiler[2],
        )
        self.cta_tile_shape_mnk_sfb = (
            self.mma_tiler_sfb[0] // cute.size(tiled_mma.thr_id.shape),
            self.mma_tiler_sfb[1],
            self.mma_tiler_sfb[2],
        )

        # Compute cluster layout
        self.cluster_layout_vmnk = cute.tiled_divide(
            cute.make_layout((*self.cluster_shape_mn, 1)),
            (tiled_mma.thr_id.shape,),
        )
        self.cluster_layout_sfb_vmnk = cute.tiled_divide(
            cute.make_layout((*self.cluster_shape_mn, 1)),
            (tiled_mma_sfb.thr_id.shape,),
        )

        # Compute number of multicast CTAs for A/B
        self.num_mcast_ctas_a = cute.size(self.cluster_layout_vmnk.shape[2])
        self.num_mcast_ctas_b = cute.size(self.cluster_layout_vmnk.shape[1])
        self.num_mcast_ctas_sfb = cute.size(self.cluster_layout_sfb_vmnk.shape[1])
        self.is_a_mcast = self.num_mcast_ctas_a > 1
        self.is_b_mcast = self.num_mcast_ctas_b > 1
        self.is_sfb_mcast = self.num_mcast_ctas_sfb > 1

        # Compute epilogue subtile
        self.epi_tile = sm100_utils.compute_epilogue_tile_shape(
            self.cta_tile_shape_mnk,
            self.use_2cta_instrs,
            self.c_layout,
            c_dtype,
        )
        self.epi_tile_n = cute.size(self.epi_tile[1])

        # Setup A/B/C stage count in shared memory and ACC stage count in tensor memory
        self.num_acc_stage, self.num_ab_stage, self.num_c_stage = self._compute_stages(
            tiled_mma,
            self.mma_tiler,
            ab_dtype,
            ab_dtype,
            self.epi_tile,
            c_dtype,
            self.c_layout,
            sf_dtype,
            sf_vec_size,
            self.smem_capacity,
            self.occupancy,
        )
        if self.num_ab_stage_override is not None and self.num_ab_stage_override > 0:
            self.num_ab_stage = max(2, min(30, int(self.num_ab_stage_override)))
        if self.num_c_stage_override is not None and self.num_c_stage_override > 0:
            self.num_c_stage = max(1, min(4, int(self.num_c_stage_override)))


        # Compute A/B/SFA/SFB/C shared memory layout
        self.a_smem_layout_staged = sm100_utils.make_smem_layout_a(
            tiled_mma,
            self.mma_tiler,
            ab_dtype,
            self.num_ab_stage,
        )
        self.b_smem_layout_staged = sm100_utils.make_smem_layout_b(
            tiled_mma,
            self.mma_tiler,
            ab_dtype,
            self.num_ab_stage,
        )
        self.sfa_smem_layout_staged = blockscaled_utils.make_smem_layout_sfa(
            tiled_mma,
            self.mma_tiler,
            sf_vec_size,
            self.num_ab_stage,
        )
        self.sfb_smem_layout_staged = blockscaled_utils.make_smem_layout_sfb(
            tiled_mma,
            self.mma_tiler,
            sf_vec_size,
            self.num_ab_stage,
        )
        self.c_smem_layout_staged = sm100_utils.make_smem_layout_epi(
            c_dtype,
            self.c_layout,
            self.epi_tile,
            self.num_c_stage,
        )

        # Overlap and double buffer accumulator when num_acc_stage == 1 for cta_tile_n = 256 case
        self.overlapping_accum = self.num_acc_stage == 1

        # Compute number of TMEM columns for SFA/SFB/Accumulator
        # NOTE: TMEM columns must always be computed with factor 4, NOT mma_inst_tile_k.
        # The SMEM layout shape is constant (due to divide-by-mma_inst_tile_k cancellation),
        # so TMEM layout derived from SMEM always expects the same number of columns.
        sf_atom_mn = 32
        tmem_k_factor = 4  # Hardware constant, not mma_inst_tile_k
        # Double-buffer scale factors in TMEM for S2T pipelining
        self.num_sf_stages = 2
        self.num_sfa_tmem_cols_per_stage = (
            self.cta_tile_shape_mnk[0] // sf_atom_mn
        ) * tmem_k_factor
        self.num_sfb_tmem_cols_per_stage = (
            self.cta_tile_shape_mnk_sfb[1] // sf_atom_mn
        ) * tmem_k_factor
        # Total SF columns = (SFA + SFB) * num_stages
        self.num_sf_tmem_cols = (
            self.num_sfa_tmem_cols_per_stage + self.num_sfb_tmem_cols_per_stage
        ) * self.num_sf_stages
        self.num_accumulator_tmem_cols = (
            self.cta_tile_shape_mnk[1] * self.num_acc_stage
            if not self.overlapping_accum
            else self.cta_tile_shape_mnk[1] * 2 - self.num_sf_tmem_cols
        )

        # Only when overlapping_accum is enabled, we need to release accumulator buffer early in epilogue
        self.iter_acc_early_release_in_epilogue = self.num_sf_tmem_cols // self.epi_tile_n

    @cute.jit
    def __call__(
        self,
        a_ptr: cute.Pointer,
        b_ptr: cute.Pointer,
        sfa_ptr: cute.Pointer,
        sfb_ptr: cute.Pointer,
        c_ptr: cute.Pointer,
        shape_mnkl: Tuple[int, int, int, int],
        max_active_clusters: cutlass.Constexpr,
        epilogue_op: cutlass.Constexpr = lambda x: x,
    ):
        m, n, k, l = shape_mnkl

        # Create tensors from pointers with proper layouts
        # A is (M, K, L) K-major
        a_layout = cute.make_layout((m, k, l), stride=(k, 1, m * k))
        a_tensor = cute.make_tensor(a_ptr, a_layout)

        # B is (N, K, L) K-major
        b_layout = cute.make_layout((n, k, l), stride=(k, 1, n * k))
        b_tensor = cute.make_tensor(b_ptr, b_layout)

        # C is (M, N, L) row-major
        c_layout = cute.make_layout((m, n, l), stride=(n, 1, m * n))
        c_tensor = cute.make_tensor(c_ptr, c_layout)

        # Get major modes from layouts
        self.a_major_mode = utils.LayoutEnum.from_tensor(a_tensor).mma_major_mode()
        self.b_major_mode = utils.LayoutEnum.from_tensor(b_tensor).mma_major_mode()
        self.c_layout = utils.LayoutEnum.from_tensor(c_tensor)

        # Setup attributes that dependent on gemm inputs
        self._setup_attributes()

        # Setup sfa/sfb tensor by filling A/B tensor to scale factor atom layout
        # ((Atom_M, Rest_M),(Atom_K, Rest_K),RestL)
        sfa_layout = blockscaled_utils.tile_atom_to_shape_SF(
            a_tensor.shape, sf_vec_size
        )
        sfa_tensor = cute.make_tensor(sfa_ptr, sfa_layout)

        # ((Atom_N, Rest_N),(Atom_K, Rest_K),RestL)
        sfb_layout = blockscaled_utils.tile_atom_to_shape_SF(
            b_tensor.shape, sf_vec_size
        )
        sfb_tensor = cute.make_tensor(sfb_ptr, sfb_layout)

        tiled_mma = sm100_utils.make_blockscaled_trivial_tiled_mma(
            ab_dtype,
            self.a_major_mode,
            self.b_major_mode,
            sf_dtype,
            sf_vec_size,
            self.cta_group,
            self.mma_inst_shape_mn,
        )

        tiled_mma_sfb = sm100_utils.make_blockscaled_trivial_tiled_mma(
            ab_dtype,
            self.a_major_mode,
            self.b_major_mode,
            sf_dtype,
            sf_vec_size,
            cute.nvgpu.tcgen05.CtaGroup.ONE,
            self.mma_inst_shape_mn_sfb,
        )
        atom_thr_size = cute.size(tiled_mma.thr_id.shape)

        # Setup TMA load for A
        a_op = sm100_utils.cluster_shape_to_tma_atom_A(
            self.cluster_shape_mn, tiled_mma.thr_id
        )
        a_smem_layout = cute.slice_(self.a_smem_layout_staged, (None, None, None, 0))
        tma_atom_a, tma_tensor_a = cute.nvgpu.make_tiled_tma_atom_A(
            a_op,
            a_tensor,
            a_smem_layout,
            self.mma_tiler,
            tiled_mma,
            self.cluster_layout_vmnk.shape,
        )

        # Setup TMA load for B
        b_op = sm100_utils.cluster_shape_to_tma_atom_B(
            self.cluster_shape_mn, tiled_mma.thr_id
        )
        b_smem_layout = cute.slice_(self.b_smem_layout_staged, (None, None, None, 0))
        tma_atom_b, tma_tensor_b = cute.nvgpu.make_tiled_tma_atom_B(
            b_op,
            b_tensor,
            b_smem_layout,
            self.mma_tiler,
            tiled_mma,
            self.cluster_layout_vmnk.shape,
        )

        # Setup TMA load for SFA
        sfa_op = sm100_utils.cluster_shape_to_tma_atom_A(
            self.cluster_shape_mn, tiled_mma.thr_id
        )
        sfa_smem_layout = cute.slice_(
            self.sfa_smem_layout_staged, (None, None, None, 0)
        )
        tma_atom_sfa, tma_tensor_sfa = cute.nvgpu.make_tiled_tma_atom_A(
            sfa_op,
            sfa_tensor,
            sfa_smem_layout,
            self.mma_tiler,
            tiled_mma,
            self.cluster_layout_vmnk.shape,
            internal_type=cutlass.Int16,
        )

        # Setup TMA load for SFB
        sfb_op = sm100_utils.cluster_shape_to_tma_atom_SFB(
            self.cluster_shape_mn, tiled_mma.thr_id
        )
        sfb_smem_layout = cute.slice_(
            self.sfb_smem_layout_staged, (None, None, None, 0)
        )
        tma_atom_sfb, tma_tensor_sfb = cute.nvgpu.make_tiled_tma_atom_B(
            sfb_op,
            sfb_tensor,
            sfb_smem_layout,
            self.mma_tiler_sfb,
            tiled_mma_sfb,
            self.cluster_layout_sfb_vmnk.shape,
            internal_type=cutlass.Int16,
        )

        if cutlass.const_expr(self.cta_tile_shape_mnk[1] == 192):
            x = tma_tensor_sfb.stride[0][1]
            y = cute.ceil_div(tma_tensor_sfb.shape[0][1], 4)

            new_shape = (
                (
                    tma_tensor_sfb.shape[0][0],
                    ((2, 2), y)
                ),
                tma_tensor_sfb.shape[1],
                tma_tensor_sfb.shape[2]
            )
            # Use right multiplication for ScaledBasis (3 * x instead of x * 3)
            x_times_3 = 3 * x
            new_stride = (
                (
                    tma_tensor_sfb.stride[0][0],
                    ((x, x), x_times_3)
                ),
                tma_tensor_sfb.stride[1],
                tma_tensor_sfb.stride[2]
            )
            tma_tensor_sfb_new_layout = cute.make_layout(new_shape, stride=new_stride)
            tma_tensor_sfb = cute.make_tensor(tma_tensor_sfb.iterator, tma_tensor_sfb_new_layout)

        a_copy_size = cute.size_in_bytes(ab_dtype, a_smem_layout)
        b_copy_size = cute.size_in_bytes(ab_dtype, b_smem_layout)
        sfa_copy_size = cute.size_in_bytes(sf_dtype, sfa_smem_layout)
        sfb_copy_size = cute.size_in_bytes(sf_dtype, sfb_smem_layout)
        self.num_tma_load_bytes = (
            a_copy_size + b_copy_size + sfa_copy_size + sfb_copy_size
        ) * atom_thr_size

        # Setup TMA store for C
        epi_smem_layout = cute.slice_(self.c_smem_layout_staged, (None, None, 0))
        tma_atom_c, tma_tensor_c = cpasync.make_tiled_tma_atom(
            cpasync.CopyBulkTensorTileS2GOp(),
            c_tensor,
            epi_smem_layout,
            self.epi_tile,
        )

        # Compute grid size
        self.tile_sched_params, grid = self._compute_grid(
            c_tensor,
            self.cta_tile_shape_mnk,
            self.cluster_shape_mn,
            max_active_clusters,
        )

        self.buffer_align_bytes = 1024

        # Define shared storage for kernel
        @cute.struct
        class SharedStorage:
            ab_full_mbar_ptr: cute.struct.MemRange[cutlass.Int64, self.num_ab_stage]
            ab_empty_mbar_ptr: cute.struct.MemRange[cutlass.Int64, self.num_ab_stage]
            acc_full_mbar_ptr: cute.struct.MemRange[cutlass.Int64, self.num_acc_stage]
            acc_empty_mbar_ptr: cute.struct.MemRange[cutlass.Int64, self.num_acc_stage]
            tmem_dealloc_mbar_ptr: cutlass.Int64
            tmem_holding_buf: cutlass.Int32
            # (EPI_TILE_M, EPI_TILE_N, STAGE)
            sC: cute.struct.Align[
                cute.struct.MemRange[
                    c_dtype,
                    cute.cosize(self.c_smem_layout_staged.outer),
                ],
                self.buffer_align_bytes,
            ]
            # (MMA, MMA_M, MMA_K, STAGE)
            sA: cute.struct.Align[
                cute.struct.MemRange[
                    ab_dtype, cute.cosize(self.a_smem_layout_staged.outer)
                ],
                self.buffer_align_bytes,
            ]
            # (MMA, MMA_N, MMA_K, STAGE)
            sB: cute.struct.Align[
                cute.struct.MemRange[
                    ab_dtype, cute.cosize(self.b_smem_layout_staged.outer)
                ],
                self.buffer_align_bytes,
            ]
            # (MMA, MMA_M, MMA_K, STAGE)
            sSFA: cute.struct.Align[
                cute.struct.MemRange[
                    sf_dtype, cute.cosize(self.sfa_smem_layout_staged)
                ],
                self.buffer_align_bytes,
            ]
            # (MMA, MMA_N, MMA_K, STAGE)
            sSFB: cute.struct.Align[
                cute.struct.MemRange[
                    sf_dtype, cute.cosize(self.sfb_smem_layout_staged)
                ],
                self.buffer_align_bytes,
            ]

        self.shared_storage = SharedStorage

        # Launch the kernel synchronously
        self.kernel(
            tiled_mma,
            tiled_mma_sfb,
            tma_atom_a,
            tma_tensor_a,
            tma_atom_b,
            tma_tensor_b,
            tma_atom_sfa,
            tma_tensor_sfa,
            tma_atom_sfb,
            tma_tensor_sfb,
            tma_atom_c,
            tma_tensor_c,
            self.cluster_layout_vmnk,
            self.cluster_layout_sfb_vmnk,
            self.a_smem_layout_staged,
            self.b_smem_layout_staged,
            self.sfa_smem_layout_staged,
            self.sfb_smem_layout_staged,
            self.c_smem_layout_staged,
            self.epi_tile,
            self.tile_sched_params,
            epilogue_op,
        ).launch(
            grid=grid,
            block=[self.threads_per_cta, 1, 1],
            cluster=(*self.cluster_shape_mn, 1),
            min_blocks_per_mp=1,
        )
        return

    # GPU device kernel
    @cute.kernel
    def kernel(
        self,
        tiled_mma: cute.TiledMma,
        tiled_mma_sfb: cute.TiledMma,
        tma_atom_a: cute.CopyAtom,
        mA_mkl: cute.Tensor,
        tma_atom_b: cute.CopyAtom,
        mB_nkl: cute.Tensor,
        tma_atom_sfa: cute.CopyAtom,
        mSFA_mkl: cute.Tensor,
        tma_atom_sfb: cute.CopyAtom,
        mSFB_nkl: cute.Tensor,
        tma_atom_c: cute.CopyAtom,
        mC_mnl: cute.Tensor,
        cluster_layout_vmnk: cute.Layout,
        cluster_layout_sfb_vmnk: cute.Layout,
        a_smem_layout_staged: cute.ComposedLayout,
        b_smem_layout_staged: cute.ComposedLayout,
        sfa_smem_layout_staged: cute.Layout,
        sfb_smem_layout_staged: cute.Layout,
        c_smem_layout_staged: Union[cute.Layout, cute.ComposedLayout],
        epi_tile: cute.Tile,
        tile_sched_params: utils.PersistentTileSchedulerParams,
        epilogue_op: cutlass.Constexpr,
    ):
        """
        GPU device kernel performing the Persistent batched GEMM computation.
        """
        warp_idx = cute.arch.warp_idx()
        warp_idx = cute.arch.make_warp_uniform(warp_idx)

        #
        # Prefetch tma desc
        #
        if warp_idx == self.tma_warp_id:
            cpasync.prefetch_descriptor(tma_atom_a)
            cpasync.prefetch_descriptor(tma_atom_b)
            cpasync.prefetch_descriptor(tma_atom_sfa)
            cpasync.prefetch_descriptor(tma_atom_sfb)
            cpasync.prefetch_descriptor(tma_atom_c)

        use_2cta_instrs = cute.size(tiled_mma.thr_id.shape) == 2

        #
        # Setup cta/thread coordinates
        #
        # Coords inside cluster
        bidx, bidy, bidz = cute.arch.block_idx()
        mma_tile_coord_v = bidx % cute.size(tiled_mma.thr_id.shape)
        is_leader_cta = mma_tile_coord_v == 0
        cta_rank_in_cluster = cute.arch.make_warp_uniform(
            cute.arch.block_idx_in_cluster()
        )
        block_in_cluster_coord_vmnk = cluster_layout_vmnk.get_flat_coord(
            cta_rank_in_cluster
        )
        block_in_cluster_coord_sfb_vmnk = cluster_layout_sfb_vmnk.get_flat_coord(
            cta_rank_in_cluster
        )
        # Coord inside cta
        tidx, _, _ = cute.arch.thread_idx()

        #
        # Alloc and init: a+b full/empty, accumulator full/empty, tensor memory dealloc barrier
        #
        smem = utils.SmemAllocator()
        storage = smem.allocate(self.shared_storage)

        # Initialize mainloop ab_pipeline (barrier) and states
        ab_pipeline_producer_group = pipeline.CooperativeGroup(pipeline.Agent.Thread)
        num_tma_producer = self.num_mcast_ctas_a + self.num_mcast_ctas_b - 1
        ab_pipeline_consumer_group = pipeline.CooperativeGroup(
            pipeline.Agent.Thread, num_tma_producer
        )
        ab_pipeline = pipeline.PipelineTmaUmma.create(
            barrier_storage=storage.ab_full_mbar_ptr.data_ptr(),
            num_stages=self.num_ab_stage,
            producer_group=ab_pipeline_producer_group,
            consumer_group=ab_pipeline_consumer_group,
            tx_count=self.num_tma_load_bytes,
            cta_layout_vmnk=cluster_layout_vmnk,
            defer_sync=True,
        )

        # Initialize acc_pipeline (barrier) and states
        acc_pipeline_producer_group = pipeline.CooperativeGroup(pipeline.Agent.Thread)
        num_acc_consumer_threads = len(self.epilog_warp_id) * (
            2 if use_2cta_instrs else 1
        )
        acc_pipeline_consumer_group = pipeline.CooperativeGroup(
            pipeline.Agent.Thread, num_acc_consumer_threads
        )
        acc_pipeline = pipeline.PipelineUmmaAsync.create(
            barrier_storage=storage.acc_full_mbar_ptr.data_ptr(),
            num_stages=self.num_acc_stage,
            producer_group=acc_pipeline_producer_group,
            consumer_group=acc_pipeline_consumer_group,
            cta_layout_vmnk=cluster_layout_vmnk,
            defer_sync=True,
        )

        # Tensor memory dealloc barrier init
        tmem = utils.TmemAllocator(
            storage.tmem_holding_buf,
            barrier_for_retrieve=self.tmem_alloc_barrier,
            allocator_warp_id=self.epilog_warp_id[0],
            is_two_cta=use_2cta_instrs,
            two_cta_tmem_dealloc_mbar_ptr=storage.tmem_dealloc_mbar_ptr,
        )

        # Cluster arrive after barrier init
        pipeline_init_arrive(cluster_shape_mn=self.cluster_shape_mn, is_relaxed=True)

        #
        # Setup smem tensor A/B/SFA/SFB/C
        #
        # (EPI_TILE_M, EPI_TILE_N, STAGE)
        sC = storage.sC.get_tensor(
            c_smem_layout_staged.outer, swizzle=c_smem_layout_staged.inner
        )
        # (MMA, MMA_M, MMA_K, STAGE)
        sA = storage.sA.get_tensor(
            a_smem_layout_staged.outer, swizzle=a_smem_layout_staged.inner
        )
        # (MMA, MMA_N, MMA_K, STAGE)
        sB = storage.sB.get_tensor(
            b_smem_layout_staged.outer, swizzle=b_smem_layout_staged.inner
        )
        # (MMA, MMA_M, MMA_K, STAGE)
        sSFA = storage.sSFA.get_tensor(sfa_smem_layout_staged)
        # (MMA, MMA_N, MMA_K, STAGE)
        sSFB = storage.sSFB.get_tensor(sfb_smem_layout_staged)

        #
        # Compute multicast mask for A/B/SFA/SFB buffer full
        #
        a_full_mcast_mask = None
        b_full_mcast_mask = None
        sfa_full_mcast_mask = None
        sfb_full_mcast_mask = None
        if cutlass.const_expr(self.is_a_mcast or self.is_b_mcast or use_2cta_instrs):
            a_full_mcast_mask = cpasync.create_tma_multicast_mask(
                cluster_layout_vmnk, block_in_cluster_coord_vmnk, mcast_mode=2
            )
            b_full_mcast_mask = cpasync.create_tma_multicast_mask(
                cluster_layout_vmnk, block_in_cluster_coord_vmnk, mcast_mode=1
            )
            sfa_full_mcast_mask = cpasync.create_tma_multicast_mask(
                cluster_layout_vmnk, block_in_cluster_coord_vmnk, mcast_mode=2
            )
            sfb_full_mcast_mask = cpasync.create_tma_multicast_mask(
                cluster_layout_sfb_vmnk, block_in_cluster_coord_sfb_vmnk, mcast_mode=1
            )

        #
        # Local_tile partition global tensors
        #
        # (bM, bK, RestM, RestK, RestL)
        gA_mkl = cute.local_tile(
            mA_mkl, cute.slice_(self.mma_tiler, (None, 0, None)), (None, None, None)
        )
        # (bN, bK, RestN, RestK, RestL)
        gB_nkl = cute.local_tile(
            mB_nkl, cute.slice_(self.mma_tiler, (0, None, None)), (None, None, None)
        )
        # (bM, bK, RestM, RestK, RestL)
        gSFA_mkl = cute.local_tile(
            mSFA_mkl, cute.slice_(self.mma_tiler, (None, 0, None)), (None, None, None)
        )
        # (bN, bK, RestN, RestK, RestL)
        gSFB_nkl = cute.local_tile(
            mSFB_nkl,
            cute.slice_(self.mma_tiler_sfb, (0, None, None)),
            (None, None, None),
        )
        # (bM, bN, RestM, RestN, RestL)
        gC_mnl = cute.local_tile(
            mC_mnl, cute.slice_(self.mma_tiler, (None, None, 0)), (None, None, None)
        )
        k_tile_cnt = cute.size(gA_mkl, mode=[3])

        #
        # Partition global tensor for TiledMMA_A/B/C
        #
        thr_mma = tiled_mma.get_slice(mma_tile_coord_v)
        thr_mma_sfb = tiled_mma_sfb.get_slice(mma_tile_coord_v)
        # (MMA, MMA_M, MMA_K, RestM, RestK, RestL)
        tCgA = thr_mma.partition_A(gA_mkl)
        # (MMA, MMA_N, MMA_K, RestN, RestK, RestL)
        tCgB = thr_mma.partition_B(gB_nkl)
        # (MMA, MMA_M, MMA_K, RestM, RestK, RestL)
        tCgSFA = thr_mma.partition_A(gSFA_mkl)
        # (MMA, MMA_N, MMA_K, RestN, RestK, RestL)
        tCgSFB = thr_mma_sfb.partition_B(gSFB_nkl)
        # (MMA, MMA_M, MMA_N, RestM, RestN, RestL)
        tCgC = thr_mma.partition_C(gC_mnl)

        #
        # Partition global/shared tensor for TMA load A/B
        #
        # TMA load A partition_S/D
        a_cta_layout = cute.make_layout(
            cute.slice_(cluster_layout_vmnk, (0, 0, None, 0)).shape
        )
        # ((atom_v, rest_v), STAGE)
        # ((atom_v, rest_v), RestM, RestK, RestL)
        tAsA, tAgA = cpasync.tma_partition(
            tma_atom_a,
            block_in_cluster_coord_vmnk[2],
            a_cta_layout,
            cute.group_modes(sA, 0, 3),
            cute.group_modes(tCgA, 0, 3),
        )
        # TMA load B partition_S/D
        b_cta_layout = cute.make_layout(
            cute.slice_(cluster_layout_vmnk, (0, None, 0, 0)).shape
        )
        # ((atom_v, rest_v), STAGE)
        # ((atom_v, rest_v), RestN, RestK, RestL)
        tBsB, tBgB = cpasync.tma_partition(
            tma_atom_b,
            block_in_cluster_coord_vmnk[1],
            b_cta_layout,
            cute.group_modes(sB, 0, 3),
            cute.group_modes(tCgB, 0, 3),
        )

        #  TMA load SFA partition_S/D
        sfa_cta_layout = a_cta_layout
        # ((atom_v, rest_v), STAGE)
        # ((atom_v, rest_v), RestM, RestK, RestL)
        tAsSFA, tAgSFA = cute.nvgpu.cpasync.tma_partition(
            tma_atom_sfa,
            block_in_cluster_coord_vmnk[2],
            sfa_cta_layout,
            cute.group_modes(sSFA, 0, 3),
            cute.group_modes(tCgSFA, 0, 3),
        )
        tAsSFA = cute.filter_zeros(tAsSFA)
        tAgSFA = cute.filter_zeros(tAgSFA)

        # TMA load SFB partition_S/D
        sfb_cta_layout = cute.make_layout(
            cute.slice_(cluster_layout_sfb_vmnk, (0, None, 0, 0)).shape
        )
        # ((atom_v, rest_v), STAGE)
        # ((atom_v, rest_v), RestN, RestK, RestL)
        tBsSFB, tBgSFB = cute.nvgpu.cpasync.tma_partition(
            tma_atom_sfb,
            block_in_cluster_coord_sfb_vmnk[1],
            sfb_cta_layout,
            cute.group_modes(sSFB, 0, 3),
            cute.group_modes(tCgSFB, 0, 3),
        )
        tBsSFB = cute.filter_zeros(tBsSFB)
        tBgSFB = cute.filter_zeros(tBgSFB)

        #
        # Partition shared/tensor memory tensor for TiledMMA_A/B/C
        #
        # (MMA, MMA_M, MMA_K, STAGE)
        tCrA = tiled_mma.make_fragment_A(sA)
        # (MMA, MMA_N, MMA_K, STAGE)
        tCrB = tiled_mma.make_fragment_B(sB)
        # (MMA, MMA_M, MMA_N)
        acc_shape = tiled_mma.partition_shape_C(self.mma_tiler[:2])
        if cutlass.const_expr(self.overlapping_accum):
            num_acc_stage_overlapped = 2
            tCtAcc_fake = tiled_mma.make_fragment_C(
                cute.append(acc_shape, num_acc_stage_overlapped)
            )
            # (MMA, MMA_M, MMA_N, STAGE)
            tCtAcc_fake = cute.make_tensor(
                tCtAcc_fake.iterator,
                cute.make_layout(
                    tCtAcc_fake.shape,
                    stride = (
                        tCtAcc_fake.stride[0],
                        tCtAcc_fake.stride[1],
                        tCtAcc_fake.stride[2],
                        (256 - self.num_sf_tmem_cols) * tCtAcc_fake.stride[0][1]
                    ) 
                )
            )
        else:
            # (MMA, MMA_M, MMA_N, STAGE)
            tCtAcc_fake = tiled_mma.make_fragment_C(
                cute.append(acc_shape, self.num_acc_stage)
            )

        #
        # Cluster wait before tensor memory alloc
        #
        pipeline_init_wait(cluster_shape_mn=self.cluster_shape_mn)

        #
        # Specialized TMA load warp
        #
        if warp_idx == self.tma_warp_id:
            #
            # Persistent tile scheduling loop
            #
            tile_sched = utils.StaticPersistentTileScheduler.create(
                tile_sched_params, cute.arch.block_idx(), cute.arch.grid_dim()
            )
            work_tile = tile_sched.initial_work_tile_info()

            ab_producer_state = pipeline.make_pipeline_state(
                pipeline.PipelineUserType.Producer, self.num_ab_stage
            )

            while work_tile.is_valid_tile:
                # Get tile coord from tile scheduler
                cur_tile_coord = work_tile.tile_idx
                mma_tile_coord_mnl = (
                    cur_tile_coord[0] // cute.size(tiled_mma.thr_id.shape),
                    cur_tile_coord[1],
                    cur_tile_coord[2],
                )

                #
                # Slice to per mma tile index
                #
                # ((atom_v, rest_v), RestK)
                tAgA_slice = tAgA[
                    (None, mma_tile_coord_mnl[0], None, mma_tile_coord_mnl[2])
                ]
                # ((atom_v, rest_v), RestK)
                tBgB_slice = tBgB[
                    (None, mma_tile_coord_mnl[1], None, mma_tile_coord_mnl[2])
                ]

                # ((atom_v, rest_v), RestK)
                tAgSFA_slice = tAgSFA[
                    (None, mma_tile_coord_mnl[0], None, mma_tile_coord_mnl[2])
                ]

                slice_n = mma_tile_coord_mnl[1]
                if cutlass.const_expr(self.cta_tile_shape_mnk[1] == 64):
                    slice_n = mma_tile_coord_mnl[1] // 2
                # ((atom_v, rest_v), RestK)
                tBgSFB_slice = tBgSFB[
                    (None, slice_n, None, mma_tile_coord_mnl[2])
                ]

                # Peek (try_wait) AB buffer empty for k_tile = prefetch_k_tile_cnt
                ab_producer_state.reset_count()
                peek_ab_empty_status = cutlass.Boolean(1)
                if ab_producer_state.count < k_tile_cnt:
                    peek_ab_empty_status = ab_pipeline.producer_try_acquire(
                        ab_producer_state
                    )
                #
                # Tma load loop
                #
                for k_tile in cutlass.range(0, k_tile_cnt, 1, unroll=1):
                    # Conditionally wait for AB buffer empty
                    ab_pipeline.producer_acquire(
                        ab_producer_state, peek_ab_empty_status
                    )

                    # TMA load A/B/SFA/SFB
                    cute.copy(
                        tma_atom_a,
                        tAgA_slice[(None, ab_producer_state.count)],
                        tAsA[(None, ab_producer_state.index)],
                        tma_bar_ptr=ab_pipeline.producer_get_barrier(ab_producer_state),
                        mcast_mask=a_full_mcast_mask,
                    )
                    cute.copy(
                        tma_atom_b,
                        tBgB_slice[(None, ab_producer_state.count)],
                        tBsB[(None, ab_producer_state.index)],
                        tma_bar_ptr=ab_pipeline.producer_get_barrier(ab_producer_state),
                        mcast_mask=b_full_mcast_mask,
                    )
                    cute.copy(
                        tma_atom_sfa,
                        tAgSFA_slice[(None, ab_producer_state.count)],
                        tAsSFA[(None, ab_producer_state.index)],
                        tma_bar_ptr=ab_pipeline.producer_get_barrier(ab_producer_state),
                        mcast_mask=sfa_full_mcast_mask,
                    )
                    cute.copy(
                        tma_atom_sfb,
                        tBgSFB_slice[(None, ab_producer_state.count)],
                        tBsSFB[(None, ab_producer_state.index)],
                        tma_bar_ptr=ab_pipeline.producer_get_barrier(ab_producer_state),
                        mcast_mask=sfb_full_mcast_mask,
                    )

                    # Peek (try_wait) AB buffer empty for k_tile = prefetch_k_tile_cnt + k_tile + 1
                    ab_producer_state.advance()
                    peek_ab_empty_status = cutlass.Boolean(1)
                    if ab_producer_state.count < k_tile_cnt:
                        peek_ab_empty_status = ab_pipeline.producer_try_acquire(
                            ab_producer_state
                        )

                #
                # Advance to next tile
                #
                tile_sched.advance_to_next_work()
                work_tile = tile_sched.get_current_work()

            #
            # Wait A/B buffer empty
            #
            ab_pipeline.producer_tail(ab_producer_state)

        #
        # Specialized MMA warp
        #
        if warp_idx == self.mma_warp_id:
            #
            # Bar sync for retrieve tensor memory ptr from shared mem
            #
            tmem.wait_for_alloc()

            #
            # Retrieving tensor memory ptr and make accumulator/SFA/SFB tensor
            #
            acc_tmem_ptr = tmem.retrieve_ptr(self.acc_dtype)
            # Make accumulator tmem tensor
            # (MMA, MMA_M, MMA_N, STAGE)
            tCtAcc_base = cute.make_tensor(acc_tmem_ptr, tCtAcc_fake.layout)

            # Make SFA/SFB tmem layouts
            # (MMA, MMA_M, MMA_K)
            tCtSFA_layout = blockscaled_utils.make_tmem_layout_sfa(
                tiled_mma,
                self.mma_tiler,
                sf_vec_size,
                cute.slice_(sfa_smem_layout_staged, (None, None, None, 0)),
            )
            # (MMA, MMA_N, MMA_K)
            tCtSFB_layout = blockscaled_utils.make_tmem_layout_sfb(
                tiled_mma,
                self.mma_tiler,
                sf_vec_size,
                cute.slice_(sfb_smem_layout_staged, (None, None, None, 0)),
            )

            # Double-buffered SFA TMEM tensors (buffer 0 and buffer 1)
            # Layout: [Acc] [SFA_0] [SFA_1] [SFB_0] [SFB_1]
            # Default to manual offsets to keep overlap layout invariants intact.
            sfa_tmem_ptr_0 = cute.recast_ptr(
                acc_tmem_ptr + self.num_accumulator_tmem_cols,
                dtype=sf_dtype,
            )
            sfa_tmem_ptr_1 = cute.recast_ptr(
                acc_tmem_ptr
                + self.num_accumulator_tmem_cols
                + self.num_sfa_tmem_cols_per_stage,
                dtype=sf_dtype,
            )
            tCtSFA_0 = cute.make_tensor(sfa_tmem_ptr_0, tCtSFA_layout)
            tCtSFA_1 = cute.make_tensor(sfa_tmem_ptr_1, tCtSFA_layout)

            sfb_base_offset = (
                self.num_accumulator_tmem_cols
                + self.num_sfa_tmem_cols_per_stage * self.num_sf_stages
            )
            sfb_tmem_ptr_0 = cute.recast_ptr(
                acc_tmem_ptr + sfb_base_offset,
                dtype=sf_dtype,
            )
            sfb_tmem_ptr_1 = cute.recast_ptr(
                acc_tmem_ptr + sfb_base_offset + self.num_sfb_tmem_cols_per_stage,
                dtype=sf_dtype,
            )
            tCtSFB_0 = cute.make_tensor(sfb_tmem_ptr_0, tCtSFB_layout)
            tCtSFB_1 = cute.make_tensor(sfb_tmem_ptr_1, tCtSFB_layout)
            sfb_tmem_cols = self.num_sfb_tmem_cols_per_stage

            # Non-overlapping path can safely use layout-derived offsets.
            if cutlass.const_expr(not self.overlapping_accum):
                acc_tmem_cols = tcgen05.find_tmem_tensor_col_offset(tCtAcc_base)
                sfa_tmem_ptr_0 = cute.recast_ptr(
                    acc_tmem_ptr + acc_tmem_cols,
                    dtype=sf_dtype,
                )
                tCtSFA_0 = cute.make_tensor(sfa_tmem_ptr_0, tCtSFA_layout)
                sfa_tmem_cols = tcgen05.find_tmem_tensor_col_offset(tCtSFA_0)
                sfa_tmem_ptr_1 = cute.recast_ptr(
                    acc_tmem_ptr + acc_tmem_cols + sfa_tmem_cols,
                    dtype=sf_dtype,
                )
                tCtSFA_1 = cute.make_tensor(sfa_tmem_ptr_1, tCtSFA_layout)

                sfb_base_offset = acc_tmem_cols + sfa_tmem_cols * self.num_sf_stages
                sfb_tmem_ptr_0 = cute.recast_ptr(
                    acc_tmem_ptr + sfb_base_offset,
                    dtype=sf_dtype,
                )
                tCtSFB_0 = cute.make_tensor(sfb_tmem_ptr_0, tCtSFB_layout)
                sfb_tmem_cols = tcgen05.find_tmem_tensor_col_offset(tCtSFB_0)
                sfb_tmem_ptr_1 = cute.recast_ptr(
                    acc_tmem_ptr + sfb_base_offset + sfb_tmem_cols,
                    dtype=sf_dtype,
                )
                tCtSFB_1 = cute.make_tensor(sfb_tmem_ptr_1, tCtSFB_layout)
            #
            # Partition for S2T copy of SFA/SFB (both buffers)
            #
            (
                tiled_copy_s2t_sfa,
                tCsSFA_compact_s2t,
                tCtSFA_compact_s2t_0,
            ) = self.mainloop_s2t_copy_and_partition(sSFA, tCtSFA_0)
            (
                _,
                _,
                tCtSFA_compact_s2t_1,
            ) = self.mainloop_s2t_copy_and_partition(sSFA, tCtSFA_1)
            (
                tiled_copy_s2t_sfb,
                tCsSFB_compact_s2t,
                tCtSFB_compact_s2t_0,
            ) = self.mainloop_s2t_copy_and_partition(sSFB, tCtSFB_0)
            (
                _,
                _,
                tCtSFB_compact_s2t_1,
            ) = self.mainloop_s2t_copy_and_partition(sSFB, tCtSFB_1)

            #
            # Persistent tile scheduling loop
            #
            tile_sched = utils.StaticPersistentTileScheduler.create(
                tile_sched_params, cute.arch.block_idx(), cute.arch.grid_dim()
            )
            work_tile = tile_sched.initial_work_tile_info()

            ab_consumer_state = pipeline.make_pipeline_state(
                pipeline.PipelineUserType.Consumer, self.num_ab_stage
            )
            acc_producer_state = pipeline.make_pipeline_state(
                pipeline.PipelineUserType.Producer, self.num_acc_stage
            )

            while work_tile.is_valid_tile:
                # Get tile coord from tile scheduler
                cur_tile_coord = work_tile.tile_idx
                mma_tile_coord_mnl = (
                    cur_tile_coord[0] // cute.size(tiled_mma.thr_id.shape),
                    cur_tile_coord[1],
                    cur_tile_coord[2],
                )

                # Get accumulator stage index
                if cutlass.const_expr(self.overlapping_accum):
                    acc_stage_index = acc_producer_state.phase ^ 1
                else:
                    acc_stage_index = acc_producer_state.index

                # Set tensor memory buffer for current tile
                # (MMA, MMA_M, MMA_N)
                tCtAcc = tCtAcc_base[(None, None, None, acc_stage_index)]

                # Peek (try_wait) AB buffer full for k_tile = 0
                ab_consumer_state.reset_count()
                peek_ab_full_status = cutlass.Boolean(1)
                if ab_consumer_state.count < k_tile_cnt and is_leader_cta:
                    peek_ab_full_status = ab_pipeline.consumer_try_wait(
                        ab_consumer_state
                    )

                #
                # Wait for accumulator buffer empty
                #
                if is_leader_cta:
                    acc_pipeline.producer_acquire(acc_producer_state)

                # Handle SFB offset for different tile shapes (double-buffered)
                # Create SFB MMA tensors for both buffers with appropriate offsets
                tCtSFB_mma_0 = tCtSFB_0
                tCtSFB_mma_1 = tCtSFB_1
                if cutlass.const_expr(self.cta_tile_shape_mnk[1] == 192):
                    # If this is an ODD tile, shift the TMEM start address for cta_tile_shape_n=192 case by two words (ignores first 64 columns of SFB)
                    offset = cutlass.Int32(2) if mma_tile_coord_mnl[1] % 2 == 1 else cutlass.Int32(0)
                    shifted_ptr_0 = cute.recast_ptr(
                        acc_tmem_ptr + sfb_base_offset + offset,
                        dtype=sf_dtype,
                    )
                    shifted_ptr_1 = cute.recast_ptr(
                        acc_tmem_ptr + sfb_base_offset + sfb_tmem_cols + offset,
                        dtype=sf_dtype,
                    )
                    tCtSFB_mma_0 = cute.make_tensor(shifted_ptr_0, tCtSFB_layout)
                    tCtSFB_mma_1 = cute.make_tensor(shifted_ptr_1, tCtSFB_layout)
                elif cutlass.const_expr(self.cta_tile_shape_mnk[1] == 64):
                    # Move in increments of 64 columns of SFB
                    offset = cutlass.Int32((mma_tile_coord_mnl[1] % 2) * 2)
                    shifted_ptr_0 = cute.recast_ptr(
                        acc_tmem_ptr + sfb_base_offset + offset,
                        dtype=sf_dtype,
                    )
                    shifted_ptr_1 = cute.recast_ptr(
                        acc_tmem_ptr + sfb_base_offset + sfb_tmem_cols + offset,
                        dtype=sf_dtype,
                    )
                    tCtSFB_mma_0 = cute.make_tensor(shifted_ptr_0, tCtSFB_layout)
                    tCtSFB_mma_1 = cute.make_tensor(shifted_ptr_1, tCtSFB_layout)

                #
                # Reset the ACCUMULATE field for each tile
                #
                tiled_mma.set(tcgen05.Field.ACCUMULATE, False)

                #
                # MMA mainloop with double-buffered SF TMEM
                #
                for k_tile in range(k_tile_cnt):
                    # Default to buffer 0 so variables exist outside dynamic control flow.
                    tCtSFA_compact_s2t = tCtSFA_compact_s2t_0
                    tCtSFB_compact_s2t = tCtSFB_compact_s2t_0
                    tCtSFA_mma = tCtSFA_0
                    tCtSFB_mma = tCtSFB_mma_0

                    if is_leader_cta:
                        # Select SF TMEM buffer based on pipeline stage parity
                        sf_stage_is_zero = (ab_consumer_state.index & 1) == 0
                        if sf_stage_is_zero:
                            tCtSFA_compact_s2t = tCtSFA_compact_s2t_0
                            tCtSFB_compact_s2t = tCtSFB_compact_s2t_0
                            tCtSFA_mma = tCtSFA_0
                            tCtSFB_mma = tCtSFB_mma_0
                        else:
                            tCtSFA_compact_s2t = tCtSFA_compact_s2t_1
                            tCtSFB_compact_s2t = tCtSFB_compact_s2t_1
                            tCtSFA_mma = tCtSFA_1
                            tCtSFB_mma = tCtSFB_mma_1

                        # Precompute s2t staged tensor BEFORE wait using dynamic index
                        # This allows address calculation to overlap with wait time
                        s2t_stage_coord = (
                            None,
                            None,
                            None,
                            None,
                            ab_consumer_state.index,
                        )
                        tCsSFA_compact_s2t_staged = tCsSFA_compact_s2t[s2t_stage_coord]
                        tCsSFB_compact_s2t_staged = tCsSFB_compact_s2t[s2t_stage_coord]

                        # Wait for AB buffer full
                        ab_pipeline.consumer_wait(
                            ab_consumer_state, peek_ab_full_status
                        )

                        # Copy SFA/SFB from smem to tmem (using selected buffer)
                        cute.copy(
                            tiled_copy_s2t_sfa,
                            tCsSFA_compact_s2t_staged,
                            tCtSFA_compact_s2t,
                        )
                        cute.copy(
                            tiled_copy_s2t_sfb,
                            tCsSFB_compact_s2t_staged,
                            tCtSFB_compact_s2t,
                        )

                        # MMA over k blocks
                        num_kblocks = cute.size(tCrA, mode=[2])
                        for kblock_idx in cutlass.range(num_kblocks, unroll_full=True):
                            kblock_coord = (
                                None,
                                None,
                                kblock_idx,
                                ab_consumer_state.index,
                            )
                            sf_kblock_coord = (None, None, kblock_idx)

                            tiled_mma.set(
                                tcgen05.Field.SFA, tCtSFA_mma[sf_kblock_coord].iterator
                            )
                            tiled_mma.set(
                                tcgen05.Field.SFB, tCtSFB_mma[sf_kblock_coord].iterator
                            )

                            cute.gemm(
                                tiled_mma,
                                tCtAcc,
                                tCrA[kblock_coord],
                                tCrB[kblock_coord],
                                tCtAcc,
                            )

                            tiled_mma.set(tcgen05.Field.ACCUMULATE, True)

                        # Release AB buffer
                        ab_pipeline.consumer_release(ab_consumer_state)

                    # Peek for next k tile
                    ab_consumer_state.advance()
                    peek_ab_full_status = cutlass.Boolean(1)
                    if ab_consumer_state.count < k_tile_cnt:
                        if is_leader_cta:
                            peek_ab_full_status = ab_pipeline.consumer_try_wait(
                                ab_consumer_state
                            )

                #
                # Async arrive accumulator buffer full
                #
                if is_leader_cta:
                    acc_pipeline.producer_commit(acc_producer_state)
                acc_producer_state.advance()

                #
                # Advance to next tile
                #
                tile_sched.advance_to_next_work()
                work_tile = tile_sched.get_current_work()

            #
            # Wait for accumulator buffer empty
            #
            acc_pipeline.producer_tail(acc_producer_state)
        #
        # Specialized epilogue warps
        #
        if warp_idx < self.mma_warp_id:
            #
            # Alloc tensor memory buffer
            #
            tmem.allocate(self.num_tmem_alloc_cols)

            #
            # Bar sync for retrieve tensor memory ptr from shared memory
            #
            tmem.wait_for_alloc()

            #
            # Retrieving tensor memory ptr and make accumulator tensor
            #
            acc_tmem_ptr = tmem.retrieve_ptr(self.acc_dtype)
            # (MMA, MMA_M, MMA_N, STAGE)
            tCtAcc_base = cute.make_tensor(acc_tmem_ptr, tCtAcc_fake.layout)

            #
            # Partition for epilogue
            #
            epi_tidx = tidx
            (
                tiled_copy_t2r,
                tTR_tAcc_base,
                (tTR_rAcc_0, tTR_rAcc_1),
            ) = self.epilog_tmem_copy_and_partition(
                epi_tidx, tCtAcc_base, tCgC, epi_tile, use_2cta_instrs
            )

            tTR_rC = cute.make_rmem_tensor(tTR_rAcc_0.shape, c_dtype)
            tiled_copy_r2s, tRS_rC, tRS_sC = self.epilog_smem_copy_and_partition(
                tiled_copy_t2r, tTR_rC, epi_tidx, sC
            )
            (
                tma_atom_c,
                bSG_sC,
                bSG_gC_partitioned,
            ) = self.epilog_gmem_copy_and_partition(
                epi_tidx, tma_atom_c, tCgC, epi_tile, sC
            )

            #
            # Persistent tile scheduling loop
            #
            tile_sched = utils.StaticPersistentTileScheduler.create(
                tile_sched_params, cute.arch.block_idx(), cute.arch.grid_dim()
            )
            work_tile = tile_sched.initial_work_tile_info()

            acc_consumer_state = pipeline.make_pipeline_state(
                pipeline.PipelineUserType.Consumer, self.num_acc_stage
            )

            # Threads/warps participating in tma store pipeline
            c_producer_group = pipeline.CooperativeGroup(
                pipeline.Agent.Thread,
                32 * len(self.epilog_warp_id),
            )
            c_pipeline = pipeline.PipelineTmaStore.create(
                num_stages=self.num_c_stage,
                producer_group=c_producer_group,
            )

            while work_tile.is_valid_tile:
                # Get tile coord from tile scheduler
                cur_tile_coord = work_tile.tile_idx
                mma_tile_coord_mnl = (
                    cur_tile_coord[0] // cute.size(tiled_mma.thr_id.shape),
                    cur_tile_coord[1],
                    cur_tile_coord[2],
                )

                #
                # Slice to per mma tile index
                #
                # ((ATOM_V, REST_V), EPI_M, EPI_N)
                bSG_gC = bSG_gC_partitioned[
                    (
                        None,
                        None,
                        None,
                        *mma_tile_coord_mnl,
                    )
                ]

                # Get accumulator stage index
                if cutlass.const_expr(self.overlapping_accum):
                    acc_stage_index = acc_consumer_state.phase
                    reverse_subtile = cutlass.Boolean(True) if acc_stage_index == 0 else cutlass.Boolean(False)
                else:
                    acc_stage_index = acc_consumer_state.index

                # Set tensor memory buffer for current tile
                # (T2R, T2R_M, T2R_N, EPI_M, EPI_M)
                tTR_tAcc = tTR_tAcc_base[
                    (None, None, None, None, None, acc_stage_index)
                ]

                # Precompute tensor reshaping BEFORE wait to overlap with wait time
                tTR_tAcc = cute.group_modes(tTR_tAcc, 3, cute.rank(tTR_tAcc))
                bSG_gC = cute.group_modes(bSG_gC, 1, cute.rank(bSG_gC))

                #
                # Wait for accumulator buffer full
                #
                acc_pipeline.consumer_wait(acc_consumer_state)

                #
                # Store accumulator to global memory in subtiles
                #
                subtile_cnt = cute.size(tTR_tAcc.shape, mode=[3])
                num_prev_subtiles = tile_sched.num_tiles_executed * subtile_cnt

                # Prefetch first subtile before entering loop
                if subtile_cnt > 0:
                    first_real_subtile_idx = 0
                    if cutlass.const_expr(self.overlapping_accum):
                        if reverse_subtile:
                            first_real_subtile_idx = self.cta_tile_shape_mnk[1] // self.epi_tile_n - 1
                    tTR_tAcc_mn_first = tTR_tAcc[(None, None, None, first_real_subtile_idx)]
                    cute.copy(tiled_copy_t2r, tTR_tAcc_mn_first, tTR_rAcc_0)

                for subtile_idx in cutlass.range(subtile_cnt):
                    real_subtile_idx = subtile_idx
                    if cutlass.const_expr(self.overlapping_accum):
                        if reverse_subtile:
                            real_subtile_idx = self.cta_tile_shape_mnk[1] // self.epi_tile_n - 1 - subtile_idx

                    # Double-buffered: select current and next buffer
                    curr_buf = tTR_rAcc_0 if subtile_idx % 2 == 0 else tTR_rAcc_1
                    next_buf = tTR_rAcc_1 if subtile_idx % 2 == 0 else tTR_rAcc_0

                    # Prefetch next subtile while processing current
                    if subtile_idx + 1 < subtile_cnt:
                        next_real_subtile_idx = subtile_idx + 1
                        if cutlass.const_expr(self.overlapping_accum):
                            if reverse_subtile:
                                next_real_subtile_idx = self.cta_tile_shape_mnk[1] // self.epi_tile_n - 1 - (subtile_idx + 1)
                        tTR_tAcc_mn_next = tTR_tAcc[(None, None, None, next_real_subtile_idx)]
                        cute.copy(tiled_copy_t2r, tTR_tAcc_mn_next, next_buf)

                    #
                    # Async arrive accumulator buffer empty ealier when overlapping_accum is enabled
                    #
                    if cutlass.const_expr(self.overlapping_accum):
                        if subtile_idx == self.iter_acc_early_release_in_epilogue:
                            # Fence for TMEM load
                            cute.arch.fence_view_async_tmem_load()
                            with cute.arch.elect_one():
                                acc_pipeline.consumer_release(acc_consumer_state)
                            acc_consumer_state.advance()

                    #
                    # Convert to C type (use current buffer)
                    #
                    acc_vec = tiled_copy_r2s.retile(curr_buf).load()
                    acc_vec = epilogue_op(acc_vec.to(c_dtype))
                    tRS_rC.store(acc_vec)

                    #
                    # Store C to shared memory
                    #
                    c_buffer = (num_prev_subtiles + real_subtile_idx) % self.num_c_stage
                    cute.copy(
                        tiled_copy_r2s,
                        tRS_rC,
                        tRS_sC[(None, None, None, c_buffer)],
                    )
                    # Fence and barrier to make sure shared memory store is visible to TMA store
                    cute.arch.fence_proxy(
                        cute.arch.ProxyKind.async_shared,
                        space=cute.arch.SharedSpace.shared_cta,
                    )
                    self.epilog_sync_barrier.arrive_and_wait()

                    #
                    # TMA store C to global memory
                    #
                    if warp_idx == self.epilog_warp_id[0]:
                        cute.copy(
                            tma_atom_c,
                            bSG_sC[(None, c_buffer)],
                            bSG_gC[(None, real_subtile_idx)],
                        )
                        # Fence and barrier to make sure shared memory store is visible to TMA store
                        c_pipeline.producer_commit()
                        c_pipeline.producer_acquire()
                    self.epilog_sync_barrier.arrive_and_wait()

                #
                # Async arrive accumulator buffer empty
                #
                if cutlass.const_expr(not self.overlapping_accum):
                    with cute.arch.elect_one():
                        acc_pipeline.consumer_release(acc_consumer_state)
                    acc_consumer_state.advance()

                #
                # Advance to next tile
                #
                tile_sched.advance_to_next_work()
                work_tile = tile_sched.get_current_work()

            #
            # Dealloc the tensor memory buffer
            #
            tmem.relinquish_alloc_permit()
            self.epilog_sync_barrier.arrive_and_wait()
            tmem.free(acc_tmem_ptr)
            #
            # Wait for C store complete
            #
            c_pipeline.producer_tail()

    def mainloop_s2t_copy_and_partition(
        self,
        sSF: cute.Tensor,
        tSF: cute.Tensor,
    ) -> Tuple[cute.TiledCopy, cute.Tensor, cute.Tensor]:
        """
        Make tiledCopy for smem to tmem load for scale factor tensor, then use it to partition smem memory (source) and tensor memory (destination).
        """
        # (MMA, MMA_MN, MMA_K, STAGE)
        tCsSF_compact = cute.filter_zeros(sSF)
        # (MMA, MMA_MN, MMA_K)
        tCtSF_compact = cute.filter_zeros(tSF)

        # Make S2T CopyAtom and tiledCopy
        copy_atom_s2t = cute.make_copy_atom(
            tcgen05.Cp4x32x128bOp(self.cta_group),
            sf_dtype,
        )
        tiled_copy_s2t = tcgen05.make_s2t_copy(copy_atom_s2t, tCtSF_compact)
        thr_copy_s2t = tiled_copy_s2t.get_slice(0)

        # ((ATOM_V, REST_V), Rest_Tiler, MMA_MN, MMA_K, STAGE)
        tCsSF_compact_s2t_ = thr_copy_s2t.partition_S(tCsSF_compact)
        # ((ATOM_V, REST_V), Rest_Tiler, MMA_MN, MMA_K, STAGE)
        tCsSF_compact_s2t = tcgen05.get_s2t_smem_desc_tensor(
            tiled_copy_s2t, tCsSF_compact_s2t_
        )
        # ((ATOM_V, REST_V), Rest_Tiler, MMA_MN, MMA_K)
        tCtSF_compact_s2t = thr_copy_s2t.partition_D(tCtSF_compact)

        return tiled_copy_s2t, tCsSF_compact_s2t, tCtSF_compact_s2t

    def epilog_tmem_copy_and_partition(
        self,
        tidx: cutlass.Int32,
        tAcc: cute.Tensor,
        gC_mnl: cute.Tensor,
        epi_tile: cute.Tile,
        use_2cta_instrs: Union[cutlass.Boolean, bool],
    ) -> Tuple[cute.TiledCopy, cute.Tensor, Tuple[cute.Tensor, cute.Tensor]]:
        """
        Make tiledCopy for tensor memory load, then use it to partition tensor memory (source) and register array (destination).
        Returns double-buffered register tensors for prefetch optimization.
        """
        # Make tiledCopy for tensor memory load
        copy_atom_t2r = sm100_utils.get_tmem_load_op(
            self.cta_tile_shape_mnk,
            self.c_layout,
            c_dtype,
            self.acc_dtype,
            epi_tile,
            use_2cta_instrs,
        )
        # (EPI_TILE_M, EPI_TILE_N, EPI_M, EPI_N, STAGE)
        tAcc_epi = cute.flat_divide(
            tAcc[((None, None), 0, 0, None)],
            epi_tile,
        )
        # (EPI_TILE_M, EPI_TILE_N)
        tiled_copy_t2r = tcgen05.make_tmem_copy(
            copy_atom_t2r, tAcc_epi[(None, None, 0, 0, 0)]
        )

        thr_copy_t2r = tiled_copy_t2r.get_slice(tidx)
        # (T2R, T2R_M, T2R_N, EPI_M, EPI_M, STAGE)
        tTR_tAcc = thr_copy_t2r.partition_S(tAcc_epi)

        # (EPI_TILE_M, EPI_TILE_N, EPI_M, EPI_N, RestM, RestN, RestL)
        gC_mnl_epi = cute.flat_divide(
            gC_mnl[((None, None), 0, 0, None, None, None)], epi_tile
        )
        # (T2R, T2R_M, T2R_N, EPI_M, EPI_N, RestM, RestN, RestL)
        tTR_gC = thr_copy_t2r.partition_D(gC_mnl_epi)
        # (T2R, T2R_M, T2R_N) - Double-buffered for TMEM prefetch optimization
        tTR_rAcc_0 = cute.make_rmem_tensor(
            tTR_gC[(None, None, None, 0, 0, 0, 0, 0)].shape, self.acc_dtype
        )
        tTR_rAcc_1 = cute.make_rmem_tensor(
            tTR_gC[(None, None, None, 0, 0, 0, 0, 0)].shape, self.acc_dtype
        )
        return tiled_copy_t2r, tTR_tAcc, (tTR_rAcc_0, tTR_rAcc_1)

    def epilog_smem_copy_and_partition(
        self,
        tiled_copy_t2r: cute.TiledCopy,
        tTR_rC: cute.Tensor,
        tidx: cutlass.Int32,
        sC: cute.Tensor,
    ) -> Tuple[cute.TiledCopy, cute.Tensor, cute.Tensor]:
        """
        Make tiledCopy for shared memory store, then use it to partition register array (source) and shared memory (destination).
        """
        copy_atom_r2s = sm100_utils.get_smem_store_op(
            self.c_layout, c_dtype, self.acc_dtype, tiled_copy_t2r
        )
        tiled_copy_r2s = cute.make_tiled_copy_D(copy_atom_r2s, tiled_copy_t2r)
        # (R2S, R2S_M, R2S_N, PIPE_D)
        thr_copy_r2s = tiled_copy_r2s.get_slice(tidx)
        tRS_sC = thr_copy_r2s.partition_D(sC)
        # (R2S, R2S_M, R2S_N)
        tRS_rC = tiled_copy_r2s.retile(tTR_rC)
        return tiled_copy_r2s, tRS_rC, tRS_sC

    def epilog_gmem_copy_and_partition(
        self,
        tidx: cutlass.Int32,
        atom: Union[cute.CopyAtom, cute.TiledCopy],
        gC_mnl: cute.Tensor,
        epi_tile: cute.Tile,
        sC: cute.Tensor,
    ) -> Tuple[cute.CopyAtom, cute.Tensor, cute.Tensor]:
        """Make tiledCopy for global memory store, then use it to:
        partition shared memory (source) and global memory (destination) for TMA store version.
        """
        # (EPI_TILE_M, EPI_TILE_N, EPI_M, EPI_N, RestM, RestN, RestL)
        gC_epi = cute.flat_divide(
            gC_mnl[((None, None), 0, 0, None, None, None)], epi_tile
        )

        tma_atom_c = atom
        sC_for_tma_partition = cute.group_modes(sC, 0, 2)
        gC_for_tma_partition = cute.group_modes(gC_epi, 0, 2)
        # ((ATOM_V, REST_V), EPI_M, EPI_N)
        # ((ATOM_V, REST_V), EPI_M, EPI_N, RestM, RestN, RestL)
        bSG_sC, bSG_gC = cpasync.tma_partition(
            tma_atom_c,
            0,
            cute.make_layout(1),
            sC_for_tma_partition,
            gC_for_tma_partition,
        )
        return tma_atom_c, bSG_sC, bSG_gC

    @staticmethod
    def _compute_stages(
        tiled_mma: cute.TiledMma,
        mma_tiler_mnk: Tuple[int, int, int],
        a_dtype: Type[cutlass.Numeric],
        b_dtype: Type[cutlass.Numeric],
        epi_tile: cute.Tile,
        c_dtype: Type[cutlass.Numeric],
        c_layout: utils.LayoutEnum,
        sf_dtype: Type[cutlass.Numeric],
        sf_vec_size: int,
        smem_capacity: int,
        occupancy: int,
    ) -> Tuple[int, int, int]:
        # ACC stages
        num_acc_stage = 1 if mma_tiler_mnk[1] == 256 else 2

        # Default C stages
        num_c_stage = 2

        # Calculate smem layout and size for one stage of A, B, SFA, SFB and C
        a_smem_layout_stage_one = sm100_utils.make_smem_layout_a(
            tiled_mma,
            mma_tiler_mnk,
            a_dtype,
            1,  # a tmp 1 stage is provided
        )
        b_smem_layout_staged_one = sm100_utils.make_smem_layout_b(
            tiled_mma,
            mma_tiler_mnk,
            b_dtype,
            1,  # a tmp 1 stage is provided
        )
        sfa_smem_layout_staged_one = blockscaled_utils.make_smem_layout_sfa(
            tiled_mma,
            mma_tiler_mnk,
            sf_vec_size,
            1,  # a tmp 1 stage is provided
        )
        sfb_smem_layout_staged_one = blockscaled_utils.make_smem_layout_sfb(
            tiled_mma,
            mma_tiler_mnk,
            sf_vec_size,
            1,  # a tmp 1 stage is provided
        )

        c_smem_layout_staged_one = sm100_utils.make_smem_layout_epi(
            c_dtype,
            c_layout,
            epi_tile,
            1,
        )

        ab_bytes_per_stage = (
            cute.size_in_bytes(a_dtype, a_smem_layout_stage_one)
            + cute.size_in_bytes(b_dtype, b_smem_layout_staged_one)
            + cute.size_in_bytes(sf_dtype, sfa_smem_layout_staged_one)
            + cute.size_in_bytes(sf_dtype, sfb_smem_layout_staged_one)
        )
        mbar_helpers_bytes = 1024
        c_bytes_per_stage = cute.size_in_bytes(c_dtype, c_smem_layout_staged_one)
        c_bytes = c_bytes_per_stage * num_c_stage

        # Calculate A/B/SFA/SFB stages:
        # Start with total smem per CTA (capacity / occupancy)
        # Subtract reserved bytes and initial C stages bytes
        # Divide remaining by bytes needed per A/B/SFA/SFB stage
        num_ab_stage = (
            smem_capacity // occupancy - (mbar_helpers_bytes + c_bytes)
        ) // ab_bytes_per_stage

        # Refine epilogue stages:
        # Calculate remaining smem after allocating for A/B/SFA/SFB stages and reserved bytes
        # Add remaining unused smem to epilogue
        num_c_stage += (
            smem_capacity
            - occupancy * ab_bytes_per_stage * num_ab_stage
            - occupancy * (mbar_helpers_bytes + c_bytes)
        ) // (occupancy * c_bytes_per_stage)

        return num_acc_stage, num_ab_stage, num_c_stage

    @staticmethod
    def _compute_grid(
        c: cute.Tensor,
        cta_tile_shape_mnk: Tuple[int, int, int],
        cluster_shape_mn: Tuple[int, int],
        max_active_clusters: cutlass.Constexpr,
    ) -> Tuple[utils.PersistentTileSchedulerParams, Tuple[int, int, int]]:
        """Use persistent tile scheduler to compute the grid size for the output tensor C.

        :param c: The output tensor C
        :type c: cute.Tensor
        :param cta_tile_shape_mnk: The shape (M, N, K) of the CTA tile.
        :type cta_tile_shape_mnk: tuple[int, int, int]
        :param cluster_shape_mn: Shape of each cluster in M, N dimensions.
        :type cluster_shape_mn: tuple[int, int]
        :param max_active_clusters: Maximum number of active clusters.
        :type max_active_clusters: cutlass.Constexpr

        :return: A tuple containing:
            - tile_sched_params: Parameters for the persistent tile scheduler.
            - grid: Grid shape for kernel launch.
        :rtype: Tuple[utils.PersistentTileSchedulerParams, tuple[int, int, int]]
        """
        c_shape = cute.slice_(cta_tile_shape_mnk, (None, None, 0))
        gc = cute.zipped_divide(c, tiler=c_shape)
        num_ctas_mnl = gc[(0, (None, None, None))].shape
        cluster_shape_mnl = (*cluster_shape_mn, 1)

        tile_sched_params = utils.PersistentTileSchedulerParams(
            num_ctas_mnl, cluster_shape_mnl
        )
        grid = utils.StaticPersistentTileScheduler.get_grid_shape(
            tile_sched_params, max_active_clusters
        )

        return tile_sched_params, grid

    @staticmethod
    def is_valid_dtypes_and_scale_factor_vec_size(
        ab_dtype: Type[cutlass.Numeric],
        sf_dtype: Type[cutlass.Numeric],
        sf_vec_size: int,
        c_dtype: Type[cutlass.Numeric],
    ) -> bool:
        """
        Check if the dtypes and sf_vec_size are valid combinations

        :param ab_dtype: The data type of the A and B operands
        :type ab_dtype: Type[cutlass.Numeric]
        :param sf_dtype: The data type of the scale factor
        :type sf_dtype: Type[cutlass.Numeric]
        :param sf_vec_size: The vector size of the scale factor
        :type sf_vec_size: int
        :param c_dtype: The data type of the output tensor
        :type c_dtype: Type[cutlass.Numeric]

        :return: True if the dtypes and sf_vec_size are valid, False otherwise
        :rtype: bool
        """
        is_valid = True

        # Check valid ab_dtype
        if ab_dtype not in {
            cutlass.Float4E2M1FN,
            cutlass.Float8E5M2,
            cutlass.Float8E4M3FN,
        }:
            is_valid = False

        # Check valid sf_vec_size
        if sf_vec_size not in {16, 32}:
            is_valid = False

        # Check valid sf_dtype
        if sf_dtype not in {cutlass.Float8E8M0FNU, cutlass.Float8E4M3FN}:
            is_valid = False

        # Check valid sf_dtype and sf_vec_size combinations
        if sf_dtype == cutlass.Float8E4M3FN and sf_vec_size == 32:
            is_valid = False
        if ab_dtype in {cutlass.Float8E5M2, cutlass.Float8E4M3FN} and sf_vec_size == 16:
            is_valid = False

        # Check valid c_dtype
        if c_dtype not in {
            cutlass.Float32,
            cutlass.Float16,
            cutlass.BFloat16,
            cutlass.Float8E5M2,
            cutlass.Float8E4M3FN,
        }:
            is_valid = False

        return is_valid

    @staticmethod
    def is_valid_layouts(
        ab_dtype: Type[cutlass.Numeric],
        c_dtype: Type[cutlass.Numeric],
        a_major: str,
        b_major: str,
        c_major: str,
    ) -> bool:
        """
        Check if layouts and dtypes are valid combinations

        :param ab_dtype: The data type of the A and B operands
        :type ab_dtype: Type[cutlass.Numeric]
        :param c_dtype: The data type of the output tensor
        :type c_dtype: Type[cutlass.Numeric]
        :param a_major: The major dimension of the A tensor
        :type a_major: str
        :param b_major: The major dimension of the B tensor
        :type b_major: str
        :param c_major: The major dimension of the C tensor
        :type c_major: str

        :return: True if the layouts are valid, False otherwise
        :rtype: bool
        """
        is_valid = True

        if ab_dtype is cutlass.Float4E2M1FN and not (a_major == "k" and b_major == "k"):
            is_valid = False
        return is_valid

    @staticmethod
    def is_valid_mma_tiler_and_cluster_shape(
        mma_tiler_mn: Tuple[int, int],
        cluster_shape_mn: Tuple[int, int],
    ) -> bool:
        """
        Check if the mma tiler and cluster shape are valid

        :param mma_tiler_mn: The (M, N) shape of the MMA instruction tiler
        :type mma_tiler_mn: Tuple[int, int]
        :param cluster_shape_mn: The (ClusterM, ClusterN) shape of the CTA cluster
        :type cluster_shape_mn: Tuple[int, int]

        :return: True if the mma tiler and cluster shape are valid, False otherwise
        :rtype: bool
        """
        is_valid = True
        # Skip invalid mma tile shape
        if mma_tiler_mn[0] not in [128, 256]:
            is_valid = False
        if mma_tiler_mn[1] not in [64, 128, 192, 256]:
            is_valid = False
        # Skip illegal cluster shape
        if cluster_shape_mn[0] % (2 if mma_tiler_mn[0] == 256 else 1) != 0:
            is_valid = False
        # Skip invalid cluster shape
        is_power_of_2 = lambda x: x > 0 and (x & (x - 1)) == 0
        if (
            cluster_shape_mn[0] * cluster_shape_mn[1] > 16
            or cluster_shape_mn[0] <= 0
            or cluster_shape_mn[1] <= 0
            # Special cluster shape check for scale factor multicasts.
            # Due to limited size of scale factors, we can't multicast among more than 4 CTAs.
            or cluster_shape_mn[0] > 4
            or cluster_shape_mn[1] > 4
            or not is_power_of_2(cluster_shape_mn[0])
            or not is_power_of_2(cluster_shape_mn[1])
        ):
            is_valid = False
        return is_valid

    @staticmethod
    def is_valid_tensor_alignment(
        m: int,
        n: int,
        k: int,
        l: int,
        ab_dtype: Type[cutlass.Numeric],
        c_dtype: Type[cutlass.Numeric],
        a_major: str,
        b_major: str,
        c_major: str,
    ) -> bool:
        """
        Check if the tensor alignment is valid

        :param m: The number of rows in the A tensor
        :type m: int
        :param n: The number of columns in the B tensor
        :type n: int
        :param k: The number of columns in the A tensor
        :type k: int
        :param l: The number of columns in the C tensor
        :type l: int
        :param ab_dtype: The data type of the A and B operands
        :type ab_dtype: Type[cutlass.Numeric]
        :param c_dtype: The data type of the output tensor
        :type c_dtype: Type[cutlass.Numeric]
        :param a_major: The major axis of the A tensor
        :type a_major: str
        :param b_major: The major axis of the B tensor
        :type b_major: str
        :param c_major: The major axis of the C tensor
        :type c_major: str

        :return: True if the problem shape is valid, False otherwise
        :rtype: bool
        """
        is_valid = True

        def check_contigous_16B_alignment(dtype, is_mode0_major, tensor_shape):
            major_mode_idx = 0 if is_mode0_major else 1
            num_major_elements = tensor_shape[major_mode_idx]
            num_contiguous_elements = 16 * 8 // dtype.width
            return num_major_elements % num_contiguous_elements == 0

        if (
            not check_contigous_16B_alignment(ab_dtype, a_major == "m", (m, k, l))
            or not check_contigous_16B_alignment(ab_dtype, b_major == "n", (n, k, l))
            or not check_contigous_16B_alignment(c_dtype, c_major == "m", (m, n, l))
        ):
            is_valid = False
        return is_valid

    @staticmethod
    def can_implement(
        ab_dtype: Type[cutlass.Numeric],
        sf_dtype: Type[cutlass.Numeric],
        sf_vec_size: int,
        c_dtype: Type[cutlass.Numeric],
        mma_tiler_mn: Tuple[int, int],
        cluster_shape_mn: Tuple[int, int],
        m: int,
        n: int,
        k: int,
        l: int,
        a_major: str,
        b_major: str,
        c_major: str,
    ) -> bool:
        """
        Check if the gemm can be implemented

        :param ab_dtype: The data type of the A and B operands
        :type ab_dtype: Type[cutlass.Numeric]
        :param sf_dtype: The data type of the scale factor tensor
        :type sf_dtype: Type[cutlass.Numeric]
        :param sf_vec_size: The vector size
        :type sf_vec_size: int
        :param c_dtype: The data type of the output tensor
        :type c_dtype: Type[cutlass.Numeric]
        :param mma_tiler_mn: The (M, N) shape of the MMA instruction tiler
        :type mma_tiler_mn: Tuple[int, int]
        :param cluster_shape_mn: The (ClusterM, ClusterN) shape of the CTA cluster
        :type cluster_shape_mn: Tuple[int, int]
        :param m: The number of rows in the A tensor
        :type m: int
        :param n: The number of columns in the B tensor
        :type n: int
        :param k: The number of columns in the A tensor
        :type k: int
        :param l: The number of columns in the C tensor
        :type l: int
        :param a_major: The major axis of the A tensor
        :type a_major: str
        :param b_major: The major axis of the B tensor
        :type b_major: str
        :param c_major: The major axis of the C tensor
        :type c_major: str

        :return: True if the gemm can be implemented, False otherwise
        :rtype: bool
        """
        can_implement = True
        # Skip unsupported types
        if not Sm100BlockScaledPersistentDenseGemmKernel.is_valid_dtypes_and_scale_factor_vec_size(
            ab_dtype, sf_dtype, sf_vec_size, c_dtype
        ):
            can_implement = False
        # Skip unsupported layouts
        if not Sm100BlockScaledPersistentDenseGemmKernel.is_valid_layouts(
            ab_dtype, c_dtype, a_major, b_major, c_major
        ):
            can_implement = False
        # Skip invalid mma tile shape and cluster shape
        if not Sm100BlockScaledPersistentDenseGemmKernel.is_valid_mma_tiler_and_cluster_shape(
            mma_tiler_mn, cluster_shape_mn
        ):
            can_implement = False
        # Skip illegal problem shape for load/store alignment
        if not Sm100BlockScaledPersistentDenseGemmKernel.is_valid_tensor_alignment(
            m, n, k, l, ab_dtype, c_dtype, a_major, b_major, c_major
        ):
            can_implement = False
        return can_implement


# =============================================================================
# Kernel Compilation and Dispatch
# =============================================================================

_compiled_kernel_cache = {}


@dataclass(frozen=True)
class KernelConfig:
    mma_tiler_mn: Tuple[int, int]
    cluster_shape_mn: Tuple[int, int]
    num_ab_stage: int = 0  # 0 => auto (use _compute_stages())
    num_c_stage: int = 0  # 0 => auto (use _compute_stages())
    mma_inst_tile_k: int = 4  # K-tile multiplier: 1, 2, or 4
    max_active_clusters: int = 0  # 0 => auto (use HardwareInfo)


_OPTIMAL_CONFIG = {
    (128, 7168, 16384, 1): KernelConfig(
        (128, 64),
        (1, 2),
        num_ab_stage=7,
        num_c_stage=3,
        mma_inst_tile_k=4,
        max_active_clusters=0,
    ),
    (128, 4096, 7168, 1): KernelConfig(
        (128, 64),
        (1, 2),
        num_ab_stage=7,
        num_c_stage=3,
        mma_inst_tile_k=4,
        max_active_clusters=0,
    ),
    (128, 7168, 2048, 1): KernelConfig(
        (128, 64),
        (1, 2),
        num_ab_stage=7,
        num_c_stage=3,
        mma_inst_tile_k=4,
        max_active_clusters=0,
    ),
}

_DEFAULT_CONFIG = KernelConfig(
    (128, 128),
    (1, 1),
    num_ab_stage=3,
    num_c_stage=1,
    mma_inst_tile_k=4,
    max_active_clusters=0,
)

def _cache_key(
    m: int,
    n: int,
    k: int,
    l: int,
    mma_tiler_mn: Tuple[int, int],
    cluster_shape_mn: Tuple[int, int],
    num_ab_stage: int,
    num_c_stage: int,
    mma_inst_tile_k: int,
    max_active_clusters: int,
) -> Tuple:
    return (
        m,
        n,
        k,
        l,
        mma_tiler_mn,
        cluster_shape_mn,
        num_ab_stage,
        num_c_stage,
        mma_inst_tile_k,
        max_active_clusters,
    )


def _ensure_compiled(
    m: int,
    n: int,
    k: int,
    l: int,
    mma_tiler_mn: Tuple[int, int],
    cluster_shape_mn: Tuple[int, int],
    num_ab_stage: int,
    num_c_stage: int,
    mma_inst_tile_k: int,
    max_active_clusters: int,
) -> None:
    """Compile a single (shape, tiling) variant if it's missing."""
    global _compiled_kernel_cache
    key = _cache_key(
        m,
        n,
        k,
        l,
        mma_tiler_mn,
        cluster_shape_mn,
        num_ab_stage,
        num_c_stage,
        mma_inst_tile_k,
        max_active_clusters,
    )
    if key in _compiled_kernel_cache:
        return

    num_ab_stage_override = None if num_ab_stage <= 0 else num_ab_stage
    num_c_stage_override = None if num_c_stage <= 0 else num_c_stage

    kernel_instance = Sm100BlockScaledPersistentDenseGemmKernel(
        mma_tiler_mn=mma_tiler_mn,
        cluster_shape_mn=cluster_shape_mn,
        num_ab_stage=num_ab_stage_override,
        num_c_stage=num_c_stage_override,
        mma_inst_tile_k=mma_inst_tile_k,
    )
    can_implement = kernel_instance.can_implement(
        ab_dtype,
        sf_dtype,
        16,
        c_dtype,
        mma_tiler_mn,
        cluster_shape_mn,
        m,
        n,
        k,
        l,
        a_major="k",
        b_major="k",
        c_major="n",
    )
    if not can_implement:
        raise RuntimeError(f"Cannot implement kernel for config: {key}")

    a_ptr = make_ptr(ab_dtype, 0, cute.AddressSpace.gmem, assumed_align=16)
    b_ptr = make_ptr(ab_dtype, 0, cute.AddressSpace.gmem, assumed_align=16)
    c_ptr = make_ptr(c_dtype, 0, cute.AddressSpace.gmem, assumed_align=16)
    sfa_ptr = make_ptr(sf_dtype, 0, cute.AddressSpace.gmem, assumed_align=32)
    sfb_ptr = make_ptr(sf_dtype, 0, cute.AddressSpace.gmem, assumed_align=32)

    _compiled_kernel_cache[key] = cute.compile[cute.GenerateLineInfo(True), cute.KeepPTX(True)](
        kernel_instance,
        a_ptr,
        b_ptr,
        sfa_ptr,
        sfb_ptr,
        c_ptr,
        (m, n, k, l),
        max_active_clusters,
    )


_gmem = cute.AddressSpace.gmem


def compile_kernel():
    """Pre-compile ALL required kernel configurations and build runtime cache."""
    global _compiled_kernel_cache, _runtime_cache

    if _compiled_kernel_cache is None:
        _compiled_kernel_cache = {}

    for shape_key, cfg in _OPTIMAL_CONFIG.items():
        m, n, k, l = shape_key
        num_ab_stage = max(0, int(cfg.num_ab_stage))
        num_c_stage = max(0, int(cfg.num_c_stage))
        mma_inst_tile_k = int(cfg.mma_inst_tile_k)
        max_active_clusters = int(cfg.max_active_clusters)
        if max_active_clusters <= 0:
            hardware_info = utils.HardwareInfo()
            max_active_clusters = hardware_info.get_max_active_clusters(
                cfg.cluster_shape_mn[0] * cfg.cluster_shape_mn[1]
            )
        _ensure_compiled(
            m,
            n,
            k,
            l,
            cfg.mma_tiler_mn,
            cfg.cluster_shape_mn,
            num_ab_stage,
            num_c_stage,
            mma_inst_tile_k,
            max_active_clusters,
        )

        # Build runtime cache entry with pre-allocated pointers
        cache_key = _cache_key(
            m, n, k, l,
            cfg.mma_tiler_mn,
            cfg.cluster_shape_mn,
            num_ab_stage,
            num_c_stage,
            mma_inst_tile_k,
            max_active_clusters,
        )
        compiled_kernel = _compiled_kernel_cache[cache_key]

        # Pre-allocate pointers once
        a_ptr = make_ptr(ab_dtype, 16, _gmem, assumed_align=16)
        b_ptr = make_ptr(ab_dtype, 16, _gmem, assumed_align=16)
        sfa_ptr = make_ptr(sf_dtype, 32, _gmem, assumed_align=32)
        sfb_ptr = make_ptr(sf_dtype, 32, _gmem, assumed_align=32)
        c_ptr = make_ptr(c_dtype, 16, _gmem, assumed_align=16)

        _runtime_cache[shape_key] = (compiled_kernel, a_ptr, b_ptr, sfa_ptr, sfb_ptr, c_ptr)


# Pre-built runtime state (initialized by compile_kernel)
_runtime_cache = {}  # shape -> (compiled_kernel, a_ptr, b_ptr, sfa_ptr, sfb_ptr, c_ptr)


def custom_kernel(data: input_t) -> output_t:
    """Execute kernel - minimal overhead, just pointer updates and call."""
    a, b, _, _, sfa_p, sfb_p, c = data

    # Get pre-compiled kernel and pointers for this shape
    m, n, l = c.shape
    k = a.shape[1] << 1
    shape_key = (m, n, k, l)

    # Fast path: use pre-compiled runtime cache
    if shape_key in _runtime_cache:
        kernel, a_ptr, b_ptr, sfa_ptr, sfb_ptr, c_ptr = _runtime_cache[shape_key]
    else:
        # Slow path: compile on-demand for unknown shapes
        kernel, a_ptr, b_ptr, sfa_ptr, sfb_ptr, c_ptr = _compile_for_shape(shape_key)

    # Update pointers (minimal work)
    a_ptr._pointer = a.data_ptr()
    a_ptr._c_pointer = None
    b_ptr._pointer = b.data_ptr()
    b_ptr._c_pointer = None
    sfa_ptr._pointer = sfa_p.data_ptr()
    sfa_ptr._c_pointer = None
    sfb_ptr._pointer = sfb_p.data_ptr()
    sfb_ptr._c_pointer = None
    c_ptr._pointer = c.data_ptr()
    c_ptr._c_pointer = None

    # Call kernel
    kernel(a_ptr, b_ptr, sfa_ptr, sfb_ptr, c_ptr, shape_key)
    return c


def _compile_for_shape(shape_key):
    """Compile kernel for a shape - uses _OPTIMAL_CONFIG if available."""
    global _compiled_kernel_cache, _runtime_cache

    if _compiled_kernel_cache is None:
        _compiled_kernel_cache = {}

    m, n, k, l = shape_key
    cfg = _OPTIMAL_CONFIG.get(shape_key, _DEFAULT_CONFIG)  # Look up optimal config first!

    num_ab_stage = max(0, int(cfg.num_ab_stage))
    num_c_stage = max(0, int(cfg.num_c_stage))
    mma_inst_tile_k = int(cfg.mma_inst_tile_k)
    max_active_clusters = int(cfg.max_active_clusters)
    if max_active_clusters <= 0:
        hardware_info = utils.HardwareInfo()
        max_active_clusters = hardware_info.get_max_active_clusters(
            cfg.cluster_shape_mn[0] * cfg.cluster_shape_mn[1]
        )

    _ensure_compiled(
        m, n, k, l,
        cfg.mma_tiler_mn,
        cfg.cluster_shape_mn,
        num_ab_stage,
        num_c_stage,
        mma_inst_tile_k,
        max_active_clusters,
    )

    cache_key = _cache_key(
        m, n, k, l,
        cfg.mma_tiler_mn,
        cfg.cluster_shape_mn,
        num_ab_stage,
        num_c_stage,
        mma_inst_tile_k,
        max_active_clusters,
    )
    compiled_kernel = _compiled_kernel_cache[cache_key]

    # Pre-allocate pointers
    a_ptr = make_ptr(ab_dtype, 16, _gmem, assumed_align=16)
    b_ptr = make_ptr(ab_dtype, 16, _gmem, assumed_align=16)
    sfa_ptr = make_ptr(sf_dtype, 32, _gmem, assumed_align=32)
    sfb_ptr = make_ptr(sf_dtype, 32, _gmem, assumed_align=32)
    c_ptr = make_ptr(c_dtype, 16, _gmem, assumed_align=16)

    _runtime_cache[shape_key] = (compiled_kernel, a_ptr, b_ptr, sfa_ptr, sfb_ptr, c_ptr)
    return _runtime_cache[shape_key]
scrolls · 2307 lines total

Source code from GPU Mode and the KernelBot dataset · June 9 Researcher Reciprocity License v1.0

Changes from previous submission

Against this author's previous submission submission 179783.

⋯ diff truncated: revisions differ almost entirely

Best evidence level for this revision: reported

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