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Composable Kernel: /home/docs/checkouts/readthedocs.org/user_builds/advanced-micro-devices-composable-kernel/checkouts/docs-7.0.0/include/ck_tile/ops/flatmm/kernel/flatmm_kernel.hpp Source File
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 // SPDX-License-Identifier: MIT
 // Copyright (c) 2018-2025, Advanced Micro Devices, Inc. All rights reserved.
  
 #pragma once
  
 #include <iostream>
 #include <string>
  
 #include "ck_tile/core.hpp"
 #include "ck_tile/ops/common.hpp"
 #include "ck_tile/ops/gemm/pipeline/gemm_pipeline_ag_bg_cr_scheduler.hpp"
  
 namespace ck_tile {
  
 struct FlatmmProblem
 {
     CK_TILE_HOST FlatmmProblem() = default;
     CK_TILE_HOST FlatmmProblem(
         index_t M_, index_t N_, index_t K_, index_t stride_A_, index_t stride_B_, index_t stride_C_)
         : M(M_), N(N_), K(K_), stride_A(stride_A_), stride_B(stride_B_), stride_C(stride_C_)
     {
     }
  
     index_t M;
     index_t N;
     index_t K;
     index_t stride_A;
     index_t stride_B;
     index_t stride_C;
 };
  
 struct FlatmmHostArgs : public FlatmmProblem
 {
     CK_TILE_HOST FlatmmHostArgs() = default;
     CK_TILE_HOST FlatmmHostArgs(const void* a_ptr_,
                                 const void* b_shuffle_ptr_,
                                 void* c_ptr_,
                                 index_t k_batch_,
                                 index_t M_,
                                 index_t N_,
                                 index_t K_,
                                 index_t stride_A_,
                                 index_t stride_B_,
                                 index_t stride_C_)
         : FlatmmProblem(M_, N_, K_, stride_A_, stride_B_, stride_C_),
           a_ptr(a_ptr_),
           b_shuffle_ptr(b_shuffle_ptr_),
           c_ptr(c_ptr_),
           k_batch(k_batch_)
     {
     }
  
     const void* a_ptr;
     const void* b_shuffle_ptr;
     void* c_ptr;
     index_t k_batch;
 };
  
 template <typename TilePartitioner_, typename FlatmmPipeline_, typename EpiloguePipeline_>
 struct FlatmmKernel
 {
     using TilePartitioner = remove_cvref_t<TilePartitioner_>;
     using FlatmmPipeline  = remove_cvref_t<FlatmmPipeline_>;
     using BlockGemmShape =
         remove_cvref_t<typename FlatmmPipeline::BlockGemmShape>; // TileFlatmmShape
     using EpiloguePipeline                   = remove_cvref_t<EpiloguePipeline_>;
     using ALayout                            = remove_cvref_t<typename FlatmmPipeline::ALayout>;
     using BLayout                            = remove_cvref_t<typename FlatmmPipeline::BLayout>;
     using CLayout                            = remove_cvref_t<typename FlatmmPipeline::CLayout>;
     static constexpr index_t KernelBlockSize = FlatmmPipeline::BlockSize;
  
     using ADataType = remove_cvref_t<typename FlatmmPipeline::ADataType>;
     using BDataType = remove_cvref_t<typename FlatmmPipeline::BDataType>;
     // Below type is actually accumulation data type - the output of block GEMM.
     using CDataType = remove_cvref_t<typename EpiloguePipeline::ODataType>;
  
     static constexpr auto I0   = number<0>();
     static constexpr auto I1   = number<1>();
     static constexpr auto I2   = number<2>();
     static constexpr auto idxM = I0;
     static constexpr auto idxN = I1;
     static constexpr auto idxK = I2;
  
     [[nodiscard]] CK_TILE_HOST static const std::string GetName()
     {
         // clang-format off
         return concat('_', "gemm", gemm_prec_str<ADataType, BDataType>, FlatmmPipeline::GetName());
         // clang-format on
     }
  
     CK_TILE_HOST static constexpr auto GridSize(index_t M, index_t N, index_t KBatch)
     {
         return dim3(TilePartitioner::GridSize(M, N), 1, KBatch);
     }
  
     CK_TILE_HOST static constexpr auto BlockSize() { return dim3(KernelBlockSize); }
  
     struct FlatmmKernelArgs
     {
         const void* a_ptr;
         const void* b_shuffle_ptr;
         void* c_ptr;
         index_t M;
         index_t N;
         index_t K;
         index_t stride_A;
         index_t stride_B;
         index_t stride_C;
         index_t k_batch;
     };
  
     CK_TILE_HOST static constexpr FlatmmKernelArgs MakeKernelArgs(const FlatmmHostArgs& hostArgs)
     {
         return FlatmmKernelArgs{hostArgs.a_ptr,
                                 hostArgs.b_shuffle_ptr,
                                 hostArgs.c_ptr,
                                 hostArgs.M,
                                 hostArgs.N,
                                 hostArgs.K,
                                 hostArgs.stride_A,
                                 hostArgs.stride_B,
                                 hostArgs.stride_C,
                                 hostArgs.k_batch};
     }
  
     CK_TILE_HOST_DEVICE static constexpr index_t GetSmemSize()
     {
         return max(FlatmmPipeline::GetSmemSize(), EpiloguePipeline::GetSmemSize());
     }
  
     struct SplitKBatchOffset
     {
         __device__ SplitKBatchOffset(const FlatmmKernelArgs& kargs,
                                      const std::size_t k_id = blockIdx.z)
         {
             constexpr auto K1   = TilePartitioner::BlockGemmShape::WarpTile::at(number<2>{});
             const index_t K_t   = kargs.k_batch * K1;
             const index_t KRead = (kargs.K + K_t - 1) / K_t * K1;
  
             if constexpr(std::is_same_v<tensor_layout::gemm::RowMajor, ALayout>)
             {
                 a_k_split_offset = k_id * KRead;
             }
             else if constexpr(std::is_same_v<tensor_layout::gemm::ColumnMajor, ALayout>)
             {
                 a_k_split_offset = k_id * KRead * kargs.stride_A;
             }
  
             if constexpr(std::is_same_v<tensor_layout::gemm::RowMajor, BLayout>)
             {
                 b_k_split_offset = k_id * KRead * kargs.stride_B;
             }
             else if constexpr(std::is_same_v<tensor_layout::gemm::ColumnMajor, BLayout>)
             {
                 b_k_split_offset = k_id * KRead;
             }
  
             if(k_id < static_cast<uint32_t>(kargs.k_batch - 1))
             {
                 splitted_k = KRead;
             }
             else
             {
                 splitted_k = kargs.K - KRead * (kargs.k_batch - 1);
             }
         }
  
         index_t a_k_split_offset;
         index_t b_k_split_offset;
         index_t splitted_k;
     };
  
     CK_TILE_HOST static bool IsSupportedArgument(const FlatmmKernelArgs& kargs)
     {
         if constexpr(EpiloguePipeline::GetVectorSizeC() % 2 != 0 &&
                      is_any_of<CDataType, fp16_t, bf16_t>::value)
         {
             if(kargs.k_batch != 1)
             {
                 std::cerr << "Conditions not met for Kbatch >1 !" << std::endl;
                 return false;
             }
         }
  
         if constexpr(std::is_same_v<ALayout, tensor_layout::gemm::RowMajor>)
         {
             if(kargs.K % TilePartitioner::KPerBlock != 0 && FlatmmPipeline::kPadK == false)
             {
                 std::cerr << "Can't support K that is not a multiple of KPerBlock"
                              " without padding!"
                           << std::endl;
                 return false;
             }
             if(kargs.K % FlatmmPipeline::GetVectorSizeA() != 0)
             {
                 std::cerr << "K is not a multiple of vector load size for A tensor!" << std::endl;
                 return false;
             }
         }
         else
         {
             if(kargs.M % TilePartitioner::MPerBlock != 0 && FlatmmPipeline::kPadM == false)
             {
                 std::cerr << "Can't support M that is not a multiple of MPerBlock"
                              " without padding!"
                           << std::endl;
                 return false;
             }
             if(kargs.M % FlatmmPipeline::GetVectorSizeA() != 0)
             {
                 std::cerr << "M is not a multiple of vector load size for A tensor!" << std::endl;
                 return false;
             }
         }
  
         if constexpr(std::is_same_v<BLayout, tensor_layout::gemm::RowMajor>)
         {
             if(kargs.N % TilePartitioner::NPerBlock != 0 && FlatmmPipeline::kPadN == false)
             {
                 std::cerr << "Can't support N that is not a multiple of NPerBlock"
                              " without padding!"
                           << std::endl;
                 return false;
             }
             if(kargs.N % FlatmmPipeline::GetVectorSizeB() != 0)
             {
                 std::cerr << "N is not a multiple of vector load size for B tensor!" << std::endl;
                 return false;
             }
         }
         else
         {
             if(kargs.K % TilePartitioner::KPerBlock != 0 && FlatmmPipeline::kPadK == false)
             {
                 std::cerr << "Can't support K that is not a multiple of KPerBlock"
                              " without padding!"
                           << std::endl;
                 return false;
             }
             if(kargs.K % FlatmmPipeline::GetVectorSizeB() != 0)
             {
                 std::cerr << "K is not a multiple of vector load size for B tensor!" << std::endl;
                 return false;
             }
         }
  
         if constexpr(std::is_same_v<CLayout, tensor_layout::gemm::RowMajor>)
         {
             if(kargs.N % TilePartitioner::NPerBlock != 0 && FlatmmPipeline::kPadN == false)
             {
                 std::cerr << "Can't support N that is not a multiple of NPerBlock"
                              " without padding!"
                           << std::endl;
                 return false;
             }
             if(kargs.N % EpiloguePipeline::GetVectorSizeC() != 0)
             {
                 std::cerr << "N is not a multiple of vector load size for C tensor!" << std::endl;
                 return false;
             }
         }
         else
         {
             if(kargs.M % TilePartitioner::MPerBlock != 0 && FlatmmPipeline::kPadM == false)
             {
                 std::cerr << "Can't support M that is not a multiple of MPerBlock"
                              " without padding!"
                           << std::endl;
                 return false;
             }
             if(kargs.M % EpiloguePipeline::GetVectorSizeC() != 0)
             {
                 std::cerr << "M is not a multiple of vector load size for C tensor!" << std::endl;
                 return false;
             }
         }
         return true;
     }
  
     template <memory_operation_enum DstInMemOp = memory_operation_enum::set>
     CK_TILE_DEVICE static auto MakeGemmTensorViews(const ADataType* a_ptr,
                                                    const BDataType* b_flat_ptr,
                                                    CDataType* c_ptr,
                                                    const FlatmmKernelArgs& kargs,
                                                    const SplitKBatchOffset& splitk_batch_offset)
     {
         const auto& a_tensor_view = [&]() {
             if constexpr(std::is_same_v<ALayout, tensor_layout::gemm::RowMajor>)
             {
                 return make_naive_tensor_view<address_space_enum::global>(
                     a_ptr,
                     make_tuple(kargs.M, splitk_batch_offset.splitted_k),
                     make_tuple(kargs.stride_A, 1),
                     number<FlatmmPipeline::GetVectorSizeA()>{},
                     number<1>{});
             }
             else
             {
                 return make_naive_tensor_view<address_space_enum::global>(
                     a_ptr,
                     make_tuple(splitk_batch_offset.splitted_k, kargs.M),
                     make_tuple(kargs.stride_A, 1),
                     number<FlatmmPipeline::GetVectorSizeA()>{},
                     number<1>{});
             }
         }();
  
         index_t kFlatK = FlatmmPipeline::flatKPerWarp * (splitk_batch_offset.splitted_k /
                                                          BlockGemmShape::WarpTile::at(number<2>{}));
         index_t kFlatN = kargs.N * kargs.K / kFlatK;
         const auto& b_flat_tensor_view = [&]() {
             return make_naive_tensor_view<address_space_enum::global>(
                 b_flat_ptr,
                 make_tuple(kFlatN, kFlatK),
                 make_tuple(kFlatK, 1),
                 number<FlatmmPipeline::GetVectorSizeB()>{},
                 number<1>{});
         }();
  
         // TODO: enable vector write for C in ColMajor
         const auto& c_tensor_view = [&]() {
             if constexpr(std::is_same_v<CLayout, tensor_layout::gemm::RowMajor>)
             {
                 return make_naive_tensor_view<address_space_enum::global>(
                     c_ptr,
                     make_tuple(kargs.M, kargs.N),
                     make_tuple(kargs.stride_C, 1),
                     number<EpiloguePipeline::GetVectorSizeC()>{},
                     number<1>{});
             }
             else
             {
                 return make_naive_tensor_view<address_space_enum::global>(
                     c_ptr,
                     make_tuple(kargs.M, kargs.N),
                     make_tuple(1, kargs.stride_C),
                     number<1>{},
                     number<1>{});
             }
         }();
  
         return make_tuple(a_tensor_view, b_flat_tensor_view, c_tensor_view);
     }
  
     template <typename TensorView>
     CK_TILE_DEVICE static auto MakeGemmPadViews(const TensorView& views)
     {
         const auto& a_pad_view = [&]() {
             const auto& a_tensor_view = views.at(I0);
             if constexpr(std::is_same_v<ALayout, tensor_layout::gemm::RowMajor>)
             {
                 return pad_tensor_view(a_tensor_view,
                                        make_tuple(number<TilePartitioner::MPerBlock>{},
                                                   number<TilePartitioner::KPerBlock>{}),
                                        sequence<false, FlatmmPipeline::kPadK>{});
             }
             else
             {
                 return pad_tensor_view(a_tensor_view,
                                        make_tuple(number<TilePartitioner::KPerBlock>{},
                                                   number<TilePartitioner::MPerBlock>{}),
                                        sequence<false, FlatmmPipeline::kPadM>{});
             }
         }();
  
         const auto& b_flat_tensor_view = views.at(I1);
  
         // TODO vector write in for C in ColMajor
         const auto& c_pad_view = [&]() {
             const auto& c_tensor_view = views.at(I2);
             if constexpr(std::is_same_v<CLayout, tensor_layout::gemm::RowMajor>)
             {
                 return pad_tensor_view(c_tensor_view,
                                        make_tuple(number<TilePartitioner::MPerBlock>{},
                                                   number<TilePartitioner::NPerBlock>{}),
                                        sequence<false, FlatmmPipeline::kPadN>{});
             }
             else
             {
                 return pad_tensor_view(c_tensor_view,
                                        make_tuple(number<TilePartitioner::MPerBlock>{},
                                                   number<TilePartitioner::NPerBlock>{}),
                                        sequence<FlatmmPipeline::kPadM, false>{});
             }
         }();
  
         return make_tuple(a_pad_view, b_flat_tensor_view, c_pad_view);
     }
  
     template <typename PadView>
     CK_TILE_DEVICE static auto
     MakeGemmTileWindows(const PadView& views, const index_t i_m, const index_t i_n)
     {
         const auto& a_pad_view      = views.at(I0);
         const auto& b_flat_pad_view = views.at(I1);
         const auto& c_pad_view      = views.at(I2);
  
         const auto& a_block_window = [&]() {
             if constexpr(std::is_same_v<ALayout, tensor_layout::gemm::RowMajor>)
             {
                 return make_tile_window(a_pad_view,
                                         make_tuple(number<TilePartitioner::MPerBlock>{},
                                                    number<TilePartitioner::KPerBlock>{}),
                                         {i_m, 0});
             }
             else
             {
                 return make_tile_window(a_pad_view,
                                         make_tuple(number<TilePartitioner::KPerBlock>{},
                                                    number<TilePartitioner::MPerBlock>{}),
                                         {0, i_m});
             }
         }();
  
         const auto& b_flat_block_window =
             make_tile_window(b_flat_pad_view,
                              make_tuple(number<FlatmmPipeline::flatNPerWarp>{},
                                         number<FlatmmPipeline::flatKPerWarp>{}),
                              {static_cast<int>(i_n / BlockGemmShape::WarpTile::at(idxN)), 0});
  
         auto c_block_window = make_tile_window(
             c_pad_view,
             make_tuple(number<TilePartitioner::MPerBlock>{}, number<TilePartitioner::NPerBlock>{}),
             {i_m, i_n});
  
         return make_tuple(a_block_window, b_flat_block_window, c_block_window);
     }
  
     CK_TILE_DEVICE static void RunFlatmm(const ADataType* a_ptr,
                                          const BDataType* b_flat_ptr,
                                          CDataType* c_ptr,
                                          void* smem_ptr,
                                          const FlatmmKernelArgs& kargs,
                                          const SplitKBatchOffset& splitk_batch_offset,
                                          const index_t block_idx_m,
                                          const index_t block_idx_n)
     {
         // Create Gemm tensor views, pad views and tile windows
         const auto& gemm_tensor_views_tuple =
             MakeGemmTensorViews<EpiloguePipeline::MemoryOperation>(
                 a_ptr, b_flat_ptr, c_ptr, kargs, splitk_batch_offset);
         const auto& gemm_pad_views = MakeGemmPadViews(gemm_tensor_views_tuple);
         auto gemm_tile_windows     = MakeGemmTileWindows(gemm_pad_views, block_idx_m, block_idx_n);
  
         const index_t num_loop = TilePartitioner::GetLoopNum(splitk_batch_offset.splitted_k);
  
         // Run GEMM cooperatively by whole workgroup.
         const auto& a_block_window      = gemm_tile_windows.at(I0);
         const auto& b_flat_block_window = gemm_tile_windows.at(I1);
         const auto& d_block_window      = gemm_tile_windows.at(I2);
         const auto& c_block_tile        = FlatmmPipeline{}.template operator()(
             a_block_window, b_flat_block_window, num_loop, smem_ptr);
  
         // Run Epilogue Pipeline
         auto& c_block_window = gemm_tile_windows.at(I2);
  
         EpiloguePipeline{}.template operator()<decltype(c_block_window), decltype(c_block_tile)>(
             c_block_window, c_block_tile, d_block_window, smem_ptr);
     }
  
     CK_TILE_DEVICE void operator()(FlatmmKernelArgs kargs) const
     {
         const auto [iM, iN] = TilePartitioner{kargs.M, kargs.N}.GetOutputTileIndex(blockIdx.x);
         const index_t i_m   = __builtin_amdgcn_readfirstlane(iM * TilePartitioner::MPerBlock);
         const index_t i_n   = __builtin_amdgcn_readfirstlane(iN * TilePartitioner::NPerBlock);
  
         const SplitKBatchOffset splitk_batch_offset(kargs);
         // options
         const ADataType* a_ptr =
             static_cast<const ADataType*>(kargs.a_ptr) + splitk_batch_offset.a_k_split_offset;
         const BDataType* b_flat_ptr = static_cast<const BDataType*>(kargs.b_shuffle_ptr) +
                                       splitk_batch_offset.b_k_split_offset;
         CDataType* c_ptr = static_cast<CDataType*>(kargs.c_ptr);
  
         // allocate LDS
         __shared__ char smem_ptr[GetSmemSize()];
  
         if constexpr(!(EpiloguePipeline::MemoryOperation == memory_operation_enum::atomic_add &&
                        EpiloguePipeline::GetVectorSizeC() % 2 != 0 &&
                        is_any_of<CDataType, fp16_t, bf16_t>::value))
         {
             RunFlatmm(a_ptr, b_flat_ptr, c_ptr, smem_ptr, kargs, splitk_batch_offset, i_m, i_n);
         }
     }
 };
  
 } // namespace ck_tile