Normalization/split k (#615)

example/27_layernorm/CMakeLists.txt

-add_example_executable(example_layernorm_blockwise layernorm_blockwise.cpp)
+add_example_executable(example_layernorm_fp16 layernorm_fp16.cpp)
+add_example_executable(example_layernorm_splitk_fp16 layernorm_splitk_fp16.cpp)

example/27_layernorm/common.hpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include <iostream>
+#include <numeric>
+#include <initializer_list>
+#include <cstdlib>
+#include <getopt.h>
+
+#include "ck/ck.hpp"
+#include "ck/tensor_operation/gpu/device/impl/device_normalization_impl.hpp"
+#include "ck/tensor_operation/gpu/device/impl/device_normalization_splitk_impl.hpp"
+
+#include "ck/library/utility/check_err.hpp"
+#include "ck/library/utility/device_memory.hpp"
+#include "ck/library/utility/host_common_util.hpp"
+#include "ck/library/utility/host_tensor.hpp"
+#include "ck/library/utility/host_tensor_generator.hpp"
+#include "ck/library/utility/literals.hpp"
+#include "ck/library/reference_tensor_operation/cpu/reference_layernorm.hpp"

example/27_layernorm/layernorm_fp16.cpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#include "common.hpp"
+
+using XDataType       = ck::half_t;
+using GammaDataType   = ck::half_t;
+using BetaDataType    = ck::half_t;
+using YDataType       = ck::half_t;
+using ComputeDataType = float;
+using PassThrough     = ck::tensor_operation::element_wise::PassThrough;
+
+constexpr int Rank         = 2;
+constexpr int NumReduceDim = 1;
+
+using DeviceInstance =
+    ck::tensor_operation::device::DeviceNormalizationImpl<XDataType,
+                                                          GammaDataType,
+                                                          BetaDataType,
+                                                          ComputeDataType,
+                                                          YDataType,
+                                                          PassThrough,
+                                                          Rank,
+                                                          NumReduceDim,
+                                                          256, // BlockSize
+                                                          8,   // ClusterM
+                                                          32,  // ClusterK
+                                                          1,   // SliceM
+                                                          8,   // SliceK
+                                                          1,   // XYVectorDim (0=M, 1=K)
+                                                          8,   // SrcScalarPerVector
+                                                          1,   // GammaVecDim (0=M, 1=K)
+                                                          8,   // GammaScalarPerVector
+                                                          1,   // BetaVecDim (0=M, 1=K)
+                                                          8,   // BetaScalarPerVector
+                                                          8>;  // OutScalarPerVector
+#include "run_layernorm_example.inc"
+
+int main() { return run_groupnorm_example<DeviceInstance>(); }

example/27_layernorm/layernorm_splitk_fp16.cpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#include "common.hpp"
+
+using XDataType       = ck::half_t;
+using GammaDataType   = ck::half_t;
+using BetaDataType    = ck::half_t;
+using YDataType       = ck::half_t;
+using ComputeDataType = float;
+using PassThrough     = ck::tensor_operation::element_wise::PassThrough;
+
+constexpr int Rank         = 2;
+constexpr int NumReduceDim = 1;
+
+using DeviceInstance =
+    ck::tensor_operation::device::DeviceNormalizationSplitKImpl<XDataType,
+                                                                GammaDataType,
+                                                                BetaDataType,
+                                                                ComputeDataType,
+                                                                YDataType,
+                                                                PassThrough,
+                                                                Rank,
+                                                                NumReduceDim,
+                                                                256, // BlockSize
+                                                                8,   // ClusterM
+                                                                32,  // ClusterK
+                                                                1,   // SliceM
+                                                                8,   // SliceK
+                                                                1,   // XYVectorDim (0=M, 1=K)
+                                                                8,   // XScalarPerVector
+                                                                1,   // GammaVecDim (0=M, 1=K)
+                                                                8,   // GammaScalarPerVector
+                                                                1,   // BetaVecDim (0=M, 1=K)
+                                                                8,   // BetaScalarPerVector
+                                                                8>;  // YScalarPerVector
+
+#include "run_layernorm_example.inc"
+
+int main() { return run_groupnorm_example<DeviceInstance>(); }

example/27_layernorm/layernorm_blockwise.cpp → example/27_layernorm/run_layernorm_example.inc

 // SPDX-License-Identifier: MIT
 // Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
 
-#include <iostream>
-#include <numeric>
-#include <initializer_list>
-#include <cstdlib>
-#include <getopt.h>
-
-#include "ck/ck.hpp"
-#include "ck/utility/reduction_enums.hpp"
-#include "ck/tensor_operation/gpu/device/impl/device_normalization_impl.hpp"
-#include "ck/tensor_operation/gpu/device/reduction_operator_mapping.hpp"
-
-#include "ck/library/utility/check_err.hpp"
-#include "ck/library/utility/device_memory.hpp"
-#include "ck/library/utility/host_common_util.hpp"
-#include "ck/library/utility/host_tensor.hpp"
-#include "ck/library/utility/host_tensor_generator.hpp"
-#include "ck/library/utility/literals.hpp"
-#include "ck/library/reference_tensor_operation/cpu/reference_layernorm.hpp"
-
-using XDataType       = ck::half_t;
-using GammaDataType   = ck::half_t;
-using BetaDataType    = ck::half_t;
-using YDataType       = ck::half_t;
-using ComputeDataType = float;
-using PassThrough     = ck::tensor_operation::element_wise::PassThrough;
-
-constexpr int Rank         = 2;
-constexpr int NumReduceDim = 1;
-
-using DeviceInstance =
-    ck::tensor_operation::device::DeviceNormalizationImpl<XDataType,
-                                                          GammaDataType,
-                                                          BetaDataType,
-                                                          ComputeDataType,
-                                                          YDataType,
-                                                          PassThrough,
-                                                          Rank,
-                                                          NumReduceDim,
-                                                          256, // BlockSize
-                                                          8,   // ClusterM
-                                                          32,  // ClusterK
-                                                          1,   // SliceM
-                                                          8,   // SliceK
-                                                          1,   // SrcVecDim (0=M, 1=K)
-                                                          8,   // SrcScalarPerVector
-                                                          1,   // GammaVecDim (0=M, 1=K)
-                                                          8,   // GammaScalarPerVector
-                                                          1,   // BetaVecDim (0=M, 1=K)
-                                                          8,   // BetaScalarPerVector
-                                                          8>;  // OutScalarPerVector
-
-int main()
+#pragma once
+
+template <typename DeviceInstance>
+int run_groupnorm_example()
 {
     bool time_kernel = false;
 
@@ -111,6 +63,10 @@ int main()
         return 1;
     };
 
+    size_t workspace_sz = device_instance.GetWorkSpaceSize(argument_ptr.get());
+    DeviceMem workspace_dev(workspace_sz);
+    device_instance.SetWorkSpacePointer(argument_ptr.get(), workspace_dev.GetDeviceBuffer());
+
     auto invoker_ptr = device_instance.MakeInvokerPointer();
     invoker_ptr->Run(argument_ptr.get(), StreamConfig{nullptr, time_kernel});
 
@@ -133,7 +89,8 @@ int main()
         ref_invoker.Run(ref_argument);
 
         y_dev.FromDevice(y.mData.data());
-        pass &= ck::utils::check_err(y, host_y, "Error: Incorrect results d1", 1e-3, 1e-3);
+        pass &= ck::utils::check_err(y, host_y, "Error: Incorrect results", 1e-3, 1e-3);
     }
+
     return (pass ? 0 : 1);
 }

example/42_groupnorm/CMakeLists.txt

 add_example_executable(example_groupnorm_sigmoid_mul_fp16 groupnorm_sigmoid_mul_fp16.cpp)
+add_example_executable(example_groupnorm_splitk_fp16 groupnorm_splitk_fp16.cpp)
 add_example_executable(example_groupnorm_swish_fp16 groupnorm_swish_fp16.cpp)

example/42_groupnorm/common.hpp

@@ -12,6 +12,7 @@
 #include "ck/ck.hpp"
 #include "ck/utility/reduction_enums.hpp"
 #include "ck/tensor_operation/gpu/device/impl/device_normalization_impl.hpp"
+#include "ck/tensor_operation/gpu/device/impl/device_normalization_splitk_impl.hpp"
 #include "ck/tensor_operation/gpu/device/reduction_operator_mapping.hpp"
 
 #include "ck/library/utility/fill.hpp"

example/42_groupnorm/groupnorm_splitk_fp16.cpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#include "common.hpp"
+
+constexpr int Rank         = 5;
+constexpr int NumReduceDim = 3;
+
+using XDataType       = ck::half_t;
+using GammaDataType   = ck::half_t;
+using BetaDataType    = ck::half_t;
+using YDataType       = ck::half_t;
+using ComputeDataType = float;
+using YElementOp      = ck::tensor_operation::element_wise::Swish;
+
+using DeviceInstance =
+    ck::tensor_operation::device::DeviceNormalizationSplitKImpl<XDataType,
+                                                                GammaDataType,
+                                                                BetaDataType,
+                                                                ComputeDataType,
+                                                                YDataType,
+                                                                YElementOp,
+                                                                Rank,
+                                                                NumReduceDim,
+                                                                256, // BlockSize
+                                                                1,   // ClusterM
+                                                                256, // ClusterK
+                                                                1,   // SliceM
+                                                                16,  // SliceK
+                                                                1,   // SrcVecDim (0=M, 1=K)
+                                                                2,   // SrcScalarPerVector
+                                                                1,   // GammaVecDim (0=M, 1=K)
+                                                                2,   // GammaScalarPerVector
+                                                                1,   // BetaVecDim (0=M, 1=K)
+                                                                2,   // BetaScalarPerVector
+                                                                2>;  // OutScalarPerVector
+
+#include "run_groupnorm_example.inc"
+
+int main(int argc, char* argv[]) { run_groupnorm_example(argc, argv); }

example/42_groupnorm/run_groupnorm_example.inc

@@ -73,6 +73,10 @@ int run_groupnorm_example(int argc, char* argv[])
         return 1;
     };
 
+    size_t workspace_sz = device_instance.GetWorkSpaceSize(argument_ptr.get());
+    DeviceMem workspace_dev(workspace_sz);
+    device_instance.SetWorkSpacePointer(argument_ptr.get(), workspace_dev.GetDeviceBuffer());
+
     auto invoker_ptr = device_instance.MakeInvokerPointer();
     float ave_time   = invoker_ptr->Run(argument_ptr.get(), StreamConfig{nullptr, true, true});
 

include/ck/tensor_operation/gpu/device/impl/device_gemm_multiple_d_layernorm_xdl_cshuffle.hpp

@@ -807,7 +807,7 @@ struct DeviceGemmMultipleDLayernorm_Xdl_CShuffle
         // workspace for welford intermediate mean
         workspace_size += gemm_welford_size * sizeof(EMeanVarDataType) + 64;
 
-        // workspace for welford intermediate mean
+        // workspace for welford intermediate variance
         workspace_size += gemm_welford_size * sizeof(EMeanVarDataType) + 64;
 
         // workspace for welford intermediate count

include/ck/tensor_operation/gpu/device/impl/device_normalization_impl.hpp

@@ -10,8 +10,7 @@
 #include "ck/tensor_operation/gpu/device/device_normalization.hpp"
 #include "ck/tensor_operation/gpu/device/device_reduce.hpp"
 #include "ck/tensor_operation/gpu/device/impl/device_reduce_common.hpp"
-#include "ck/tensor_operation/gpu/grid/gridwise_normalization_selector.hpp"
-#include "ck/tensor_operation/gpu/grid/gridwise_set_buffer_value.hpp"
+#include "ck/tensor_operation/gpu/grid/normalization/gridwise_normalization_selector.hpp"
 #include "ck/host_utility/device_prop.hpp"
 #include "ck/host_utility/kernel_launch.hpp"
 
@@ -20,6 +19,10 @@ namespace tensor_operation {
 namespace device {
 
 // Y = Normalization(X, Beta, Gamma)
+// M: Invarient length
+// K: Reduce length (Calculate mean and variance along K dimension)
+// eg. Length = [N, C, H, W], reduce dim = [C, H, W]
+// Then, M = N, K = C * H * W
 template <typename XDataType,
           typename GammaDataType,
           typename BetaDataType,
@@ -68,7 +71,6 @@ struct DeviceNormalizationImpl : public DeviceNormalization<XDataType,
 
     static auto MakeSrc2dDescriptor(const std::vector<index_t>& inLengths,
                                     const std::vector<index_t>& inStrides,
-                                    int blkGroupSize,
                                     int numBlockTileIteration)
     {
         constexpr index_t NumInvariantDim  = Rank - NumReduceDim;
@@ -117,10 +119,9 @@ struct DeviceNormalizationImpl : public DeviceNormalization<XDataType,
         const auto invariantLength = in_grid_desc_m_k.GetLength(Number<0>{});
         const auto reduceLength    = in_grid_desc_m_k.GetLength(Number<1>{});
 
-        const int reduceSizePerBlock = K_BlockTileSize * numBlockTileIteration;
         const auto inPad_M =
             math::integer_least_multiple(invariantLength, M_BlockTileSize) - invariantLength;
-        const auto inPad_K = reduceSizePerBlock * blkGroupSize - reduceLength;
+        const auto inPad_K = K_BlockTileSize * numBlockTileIteration - reduceLength;
 
         auto in_grid_desc_m_k_padded = transform_tensor_descriptor(
             in_grid_desc_m_k,
@@ -132,7 +133,7 @@ struct DeviceNormalizationImpl : public DeviceNormalization<XDataType,
         return (in_grid_desc_m_k_padded);
     };
 
-    using GridDesc_M_K = decltype(MakeSrc2dDescriptor({1}, {1}, 1, 1));
+    using GridDesc_M_K = decltype(MakeSrc2dDescriptor({1}, {1}, 1));
 
     struct Argument : public BaseArgument
     {
@@ -162,26 +163,22 @@ struct DeviceNormalizationImpl : public DeviceNormalization<XDataType,
             gammaStrides_ = shuffle_tensor_dimensions<Rank, NumReduceDim>(gammaStrides, reduceDims);
             betaStrides_  = shuffle_tensor_dimensions<Rank, NumReduceDim>(betaStrides, reduceDims);
 
-            long_index_t invariant_total_length;
-            long_index_t reduce_total_length;
+            long_index_t invariant_length;
+            long_index_t reduce_length;
 
-            std::tie(invariant_total_length, reduce_total_length) =
+            std::tie(invariant_length, reduce_length) =
                 get_2d_lengths<Rank, NumReduceDim>(Lengths_);
 
-            blkGroupSize_          = 1;
-            numBlockTileIteration_ = (reduce_total_length + K_BlockTileSize - 1) / K_BlockTileSize;
+            numBlockTileIteration_ = math::integer_divide_ceil(reduce_length, K_BlockTileSize);
 
-            gridSize_ = math::integer_least_multiple(invariant_total_length, M_BlockTileSize) /
-                        M_BlockTileSize * blkGroupSize_;
+            gridSize_ = math::integer_divide_ceil(invariant_length, M_BlockTileSize);
 
-            x_grid_desc_m_k_ =
-                MakeSrc2dDescriptor(Lengths_, xStrides_, blkGroupSize_, numBlockTileIteration_);
+            x_grid_desc_m_k_ = MakeSrc2dDescriptor(Lengths_, xStrides_, numBlockTileIteration_);
             gamma_grid_desc_m_k_ =
-                MakeSrc2dDescriptor(Lengths_, gammaStrides_, blkGroupSize_, numBlockTileIteration_);
+                MakeSrc2dDescriptor(Lengths_, gammaStrides_, numBlockTileIteration_);
             beta_grid_desc_m_k_ =
-                MakeSrc2dDescriptor(Lengths_, betaStrides_, blkGroupSize_, numBlockTileIteration_);
-            y_grid_desc_m_k_ =
-                MakeSrc2dDescriptor(Lengths_, yStrides_, blkGroupSize_, numBlockTileIteration_);
+                MakeSrc2dDescriptor(Lengths_, betaStrides_, numBlockTileIteration_);
+            y_grid_desc_m_k_ = MakeSrc2dDescriptor(Lengths_, yStrides_, numBlockTileIteration_);
 
             isSweeponce_ =
                 x_grid_desc_m_k_.GetLength(Number<1>{}) <= KThreadClusterSize * KThreadSliceSize;
@@ -202,7 +199,6 @@ struct DeviceNormalizationImpl : public DeviceNormalization<XDataType,
 
         YElementwiseOperation y_elementwise_op_;
 
-        int blkGroupSize_;
         int numBlockTileIteration_;
         size_t gridSize_;
 
@@ -286,6 +282,9 @@ struct DeviceNormalizationImpl : public DeviceNormalization<XDataType,
 
                 if(p_arg_->invariant_lowest_length % XSrcVectorSize != 0)
                     return false;
+
+                if(p_arg_->invariant_lowest_length % YDstVectorSize != 0)
+                    return false;
             };
         }
         else
@@ -295,12 +294,12 @@ struct DeviceNormalizationImpl : public DeviceNormalization<XDataType,
 
             if(p_arg_->Lengths_[Rank - 1] % XSrcVectorSize != 0)
                 return false;
-        };
 
-        if(p_arg_->Lengths_[Rank - 1] % YDstVectorSize != 0)
-        {
-            return false;
-        }
+            if(p_arg_->Lengths_[Rank - 1] % YDstVectorSize != 0)
+            {
+                return false;
+            }
+        };
 
         // if fastest dim is not reduced
         if constexpr(GammaSrcVectorDim == 0)

include/ck/tensor_operation/gpu/grid/gridwise_normalization_selector.hpp → include/ck/tensor_operation/gpu/grid/normalization/gridwise_normalization_selector.hpp

@@ -3,8 +3,8 @@
 
 #pragma once
 
-#include "ck/tensor_operation/gpu/grid/gridwise_normalization_naive_variance.hpp"
-#include "ck/tensor_operation/gpu/grid/gridwise_normalization_welford_variance.hpp"
+#include "ck/tensor_operation/gpu/grid/normalization/gridwise_normalization_naive_variance.hpp"
+#include "ck/tensor_operation/gpu/grid/normalization/gridwise_normalization_welford_variance.hpp"
 
 namespace ck {
 template <typename GridwiseReduction,

include/ck/tensor_operation/gpu/grid/normalization/gridwise_normalization_splitk_1st.hpp

+// SPDX-License-Identifier: MIT
+// Copyright (c) 2018-2022, Advanced Micro Devices, Inc. All rights reserved.
+
+#pragma once
+
+#include "ck/utility/data_type.hpp"
+#include "ck/utility/math.hpp"
+#include "ck/tensor_operation/gpu/block/blockwise_welford.hpp"
+#include "ck/tensor_operation/gpu/thread/threadwise_welford.hpp"
+#include "ck/tensor_operation/gpu/thread/threadwise_tensor_slice_transfer.hpp"
+#include "ck/tensor_operation/gpu/element/element_wise_operation.hpp"
+
+namespace ck {
+
+template <typename XDataType,
+          typename ComputeDataType,
+          typename MeanVarDataType,
+          typename XGridDesc_M_K,
+          typename MeanVarGridDesc_M_KBlock,
+          index_t BlockSize,
+          index_t MThreadClusterSize,
+          index_t KThreadClusterSize,
+          index_t MThreadSliceSize,
+          index_t KThreadSliceSize,
+          index_t XSrcVectorDim,
+          index_t XSrcVectorSize>
+struct GridwiseNormalizationSplitK1st
+{
+    static_assert((XSrcVectorDim == 0 && MThreadSliceSize % XSrcVectorSize == 0) ||
+                      (XSrcVectorDim == 1 && KThreadSliceSize % XSrcVectorSize == 0),
+                  "Invalid thread slice sizes and/or vector sizes configuration, please check!");
+
+    static constexpr bool reorder_thread_cluster = (XSrcVectorDim == 0);
+
+    static constexpr auto I0 = Number<0>{};
+    static constexpr auto I1 = Number<1>{};
+    static constexpr auto I2 = Number<2>{};
+
+    using ThreadClusterLengths_M_K = Sequence<MThreadClusterSize, KThreadClusterSize>;
+
+    using ThreadBufferDimAccessOrder =
+        typename conditional<reorder_thread_cluster, Sequence<1, 0>, Sequence<0, 1>>::type;
+
+    using ThreadClusterArrangeOrder =
+        typename conditional<reorder_thread_cluster, Sequence<1, 0>, Sequence<0, 1>>::type;
+
+    static constexpr auto thread_cluster_desc =
+        make_cluster_descriptor(ThreadClusterLengths_M_K{}, ThreadClusterArrangeOrder{});
+
+    using ThreadBufferLengths_M_K                = Sequence<MThreadSliceSize, XSrcVectorSize>;
+    static constexpr auto thread_buffer_desc_m_k = make_naive_tensor_descriptor_packed(
+        make_tuple(Number<MThreadSliceSize>{}, Number<XSrcVectorSize>{}));
+
+    using ThreadBufferLengths_M_1 = Sequence<MThreadSliceSize, 1>;
+    static constexpr auto thread_buffer_desc_m_1 =
+        make_naive_tensor_descriptor_packed(make_tuple(Number<MThreadSliceSize>{}, I1));
+
+    using ThreadReduceSrcDesc_M_K = decltype(make_naive_tensor_descriptor_packed(
+        make_tuple(Number<MThreadSliceSize>{}, Number<XSrcVectorSize>{})));
+    using ThreadReduceDstDesc_M =
+        decltype(make_naive_tensor_descriptor_packed(make_tuple(Number<MThreadSliceSize>{})));
+
+    using ThreadwiseWelford =
+        ThreadwiseWelford<ComputeDataType, ThreadReduceSrcDesc_M_K, ThreadReduceDstDesc_M>;
+
+    using BlockwiseWelford = BlockwiseWelford<ComputeDataType,
+                                              BlockSize,
+                                              ThreadClusterLengths_M_K,
+                                              ThreadClusterArrangeOrder,
+                                              false>;
+
+    using PassThroughOp = tensor_operation::element_wise::PassThrough;
+
+    static constexpr index_t M_BlockTileSize     = MThreadClusterSize * MThreadSliceSize;
+    static constexpr index_t K_BlockTileSize     = KThreadClusterSize * KThreadSliceSize;
+    static constexpr index_t K_BlockTileStepSize = KThreadClusterSize * XSrcVectorSize;
+
+    static constexpr auto ThreadBufferNumber = Number<KThreadSliceSize / XSrcVectorSize>{};
+
+    __device__ static int
+    GetKPerThread(int kRaw, int kGridSize, int block_k_cluster_id, int thread_k_cluster_id)
+    {
+        bool is_rightmost_block = block_k_cluster_id == kGridSize - 1;
+
+        if(is_rightmost_block)
+        {
+            int left_kPerBlock = math::integer_divide_ceil(kRaw, kGridSize);
+            int kPerBlock      = kRaw % kGridSize == 0 ? left_kPerBlock : kRaw % left_kPerBlock;
+            int kPerThread =
+                kPerBlock < K_BlockTileSize ? 0 : KThreadSliceSize * (kPerBlock / K_BlockTileSize);
+            int kPerBlockTail = kPerBlock - kPerThread * KThreadClusterSize;
+
+            if(kPerBlockTail > 0)
+            {
+                static_for<0, ThreadBufferNumber, 1>{}([&](auto i) {
+                    int thread_max_len =
+                        (thread_k_cluster_id + 1) * XSrcVectorSize + K_BlockTileStepSize * i;
+                    int delta = thread_max_len - kPerBlockTail;
+                    delta     = math::clamp(thread_max_len - kPerBlockTail, 0, XSrcVectorSize);
+                    kPerThread += XSrcVectorSize - delta;
+                });
+            }
+
+            return kPerThread;
+        }
+        else
+        {
+            int kPerBlock = math::integer_divide_ceil(kRaw, kGridSize);
+            return KThreadSliceSize * (kPerBlock / K_BlockTileSize);
+        }
+    }
+
+    // Calculate mean and variance by welford along k dimension
+    __device__ static void Run(const XGridDesc_M_K& x_grid_desc_m_k,
+                               const MeanVarGridDesc_M_KBlock& mean_var_grid_desc_m_kblock,
+                               index_t num_k_block_tile_iteration,
+                               const XDataType* const __restrict__ p_x_global,
+                               MeanVarDataType* const p_mean_global,
+                               MeanVarDataType* const p_variance_global,
+                               int32_t* const p_welford_count_global)
+    {
+        auto x_thread_buf = generate_tuple(
+            [&](auto) {
+                return StaticBuffer<AddressSpaceEnum::Vgpr,
+                                    ComputeDataType,
+                                    MThreadSliceSize * XSrcVectorSize,
+                                    true>{};
+            },
+            Number<ThreadBufferNumber>{});
+
+        StaticBuffer<AddressSpaceEnum::Vgpr, ComputeDataType, MThreadSliceSize, true>
+            mean_thread_buf;
+        StaticBuffer<AddressSpaceEnum::Vgpr, ComputeDataType, MThreadSliceSize, true>
+            var_thread_buf;
+
+        const index_t thread_local_id = get_thread_local_1d_id();
+        const index_t block_global_id = get_block_1d_id();
+
+        const index_t k_grid_size        = mean_var_grid_desc_m_kblock.GetLength(I1);
+        const index_t block_m_cluster_id = block_global_id / k_grid_size;
+        const index_t block_k_cluster_id = block_global_id % k_grid_size;
+
+        const auto thread_cluster_idx =
+            thread_cluster_desc.CalculateBottomIndex(make_multi_index(thread_local_id));
+
+        const auto thread_m_cluster_id = thread_cluster_idx[I0];
+        const auto thread_k_cluster_id = thread_cluster_idx[I1];
+
+        const index_t reduceSizePerBlock = K_BlockTileSize * num_k_block_tile_iteration;
+
+        auto threadwise_x_load = ThreadwiseTensorSliceTransfer_v2<XDataType,
+                                                                  ComputeDataType,
+                                                                  XGridDesc_M_K,
+                                                                  decltype(thread_buffer_desc_m_k),
+                                                                  ThreadBufferLengths_M_K,
+                                                                  ThreadBufferDimAccessOrder,
+                                                                  XSrcVectorDim,
+                                                                  XSrcVectorSize,
+                                                                  1,
+                                                                  true>(
+            x_grid_desc_m_k,
+            make_multi_index(
+                block_m_cluster_id * M_BlockTileSize + thread_m_cluster_id * MThreadSliceSize,
+                block_k_cluster_id * reduceSizePerBlock + thread_k_cluster_id * XSrcVectorSize));
+
+        auto mean_var_count_store_index = make_multi_index(
+            block_m_cluster_id * M_BlockTileSize + thread_m_cluster_id * MThreadSliceSize,
+            block_k_cluster_id);
+
+        auto threadwise_welford_mean_var_store =
+            ThreadwiseTensorSliceTransfer_v1r3<ComputeDataType,
+                                               MeanVarDataType,
+                                               decltype(thread_buffer_desc_m_1),
+                                               MeanVarGridDesc_M_KBlock,
+                                               PassThroughOp,
+                                               ThreadBufferLengths_M_1,
+                                               Sequence<0, 1>,
+                                               1,
+                                               1,
+                                               InMemoryDataOperationEnum::Set,
+                                               1,
+                                               true>(
+                mean_var_grid_desc_m_kblock, mean_var_count_store_index, PassThroughOp{});
+
+        constexpr auto thread_copy_fwd_step_m_k = make_multi_index(0, K_BlockTileStepSize);
+
+        const auto x_global_val_buf = make_dynamic_buffer<AddressSpaceEnum::Global>(
+            p_x_global, x_grid_desc_m_k.GetElementSpaceSize());
+
+        auto mean_global_val_buf = make_dynamic_buffer<AddressSpaceEnum::Global>(
+            p_mean_global, mean_var_grid_desc_m_kblock.GetElementSpaceSize());
+
+        auto var_global_val_buf = make_dynamic_buffer<AddressSpaceEnum::Global>(
+            p_variance_global, mean_var_grid_desc_m_kblock.GetElementSpaceSize());
+
+        auto threadwise_welford = ThreadwiseWelford();
+        int kRaw                = x_grid_desc_m_k.GetTransforms()[I2].GetUpperLengths()[I0];
+        threadwise_welford.max_count_ =
+            GetKPerThread(kRaw, k_grid_size, block_k_cluster_id, thread_k_cluster_id);
+
+        static_for<0, MThreadSliceSize, 1>{}([&](auto I) {
+            mean_thread_buf(I) = type_convert<ComputeDataType>(0.0f);
+            var_thread_buf(I)  = type_convert<ComputeDataType>(0.0f);
+        });
+
+        for(index_t k = 0; k < num_k_block_tile_iteration; ++k)
+        {
+            static_for<0, ThreadBufferNumber, 1>{}([&](auto i) {
+                threadwise_x_load.Run(x_grid_desc_m_k,
+                                      x_global_val_buf,
+                                      thread_buffer_desc_m_k,
+                                      make_tuple(I0, I0),
+                                      x_thread_buf(i));
+                threadwise_x_load.MoveSrcSliceWindow(x_grid_desc_m_k, thread_copy_fwd_step_m_k);
+                threadwise_welford.Run(x_thread_buf[i], mean_thread_buf, var_thread_buf);
+            });
+        }
+
+        int welford_count = 0;
+        static_for<0, MThreadSliceSize, 1>{}([&](auto I) {
+            if constexpr(I > 0)
+                block_sync_lds();
+
+            int count = threadwise_welford.cur_count_;
+            BlockwiseWelford::Run(mean_thread_buf(I), var_thread_buf(I), count);
+
+            // The value of count is same for all I
+            if constexpr(I == MThreadSliceSize - 1)
+                welford_count = count;
+        });
+
+        if(thread_k_cluster_id == 0)
+        {
+            threadwise_welford_mean_var_store.Run(thread_buffer_desc_m_1,
+                                                  make_tuple(I0, I0),
+                                                  mean_thread_buf,
+                                                  mean_var_grid_desc_m_kblock,
+                                                  mean_global_val_buf);
+
+            threadwise_welford_mean_var_store.Run(thread_buffer_desc_m_1,
+                                                  make_tuple(I0, I0),
+                                                  var_thread_buf,
+                                                  mean_var_grid_desc_m_kblock,
+                                                  var_global_val_buf);
+
+            if(block_m_cluster_id == 0 && thread_m_cluster_id == 0)
+                p_welford_count_global[block_k_cluster_id] = welford_count;
+        }
+    }
+};
+
+} // namespace ck