flash-attention/hopper/mainloop_fwd_sm90_tma_gmma_ws.hpp

1031 lines
52 KiB
C++

/******************************************************************************
* Copyright (c) 2024, Jay Shah, Ganesh Bikshandi, Ying Zhang, Vijay Thakkar, Pradeep Ramani, Tri Dao.
******************************************************************************/
#pragma once
#include <cutlass/cutlass.h>
#include <cutlass/array.h>
#include <cutlass/numeric_types.h>
#include <cutlass/numeric_conversion.h>
#include "cutlass/pipeline/pipeline.hpp"
#include "cute/tensor.hpp"
#include "cutlass/gemm/collective/collective_builder.hpp"
#include "named_barrier.hpp"
#include "utils.h"
namespace flash {
using namespace cute;
// 4 warps
struct SmemTransposeFp8_64x64 {
using Element = cutlass::float_e4m3_t;
using ldsm_thread_shape = Shape<_4, _1, _8, _4>;
using ldsm_value_shape = Shape<_2, _8, _2, _1>;
using ldsm_value_stride = Stride<_2, _4, _1, _0>;
using TiledCopyLDSM = decltype(make_tiled_copy(
Copy_Atom<SM75_U16x8_LDSM_T, Element>{}, Layout<ldsm_thread_shape>{},
Layout<ldsm_value_shape, ldsm_value_stride>{}));
TiledCopyLDSM tiled_copy_ldsm;
using stsm_thread_shape = Shape<_4, _1, _8, _4>;
// using stsm_thread_stride = Stride<_1, _0, _4, _32>;
#ifndef NO_FP8_COLUMN_PERMUTE
using stsm_value_shape = Shape<_4, _4, _1, _2>;
using stsm_value_stride = Stride<_1, _8, _0, _4>;
#else
using stsm_value_shape = Shape<_4, _4, _2, _1>;
using stsm_value_stride = Stride<_1, _8, _4, _0>;
#endif
using TiledCopySTSM =
decltype(make_tiled_copy(Copy_Atom<SM90_U32x4_STSM_N, Element>{},
Layout<stsm_thread_shape>{},
Layout<stsm_value_shape, stsm_value_stride>{}));
TiledCopySTSM tiled_copy_stsm;
template <class SmemTensor, class SmemTensorOut>
CUTLASS_DEVICE void operator()(SmemTensor &&s_in, SmemTensorOut &&s_out) {
using namespace cute;
auto tid = threadIdx.x;
auto thr_copy_ldsm = tiled_copy_ldsm.get_thread_slice(tid);
auto thr_copy_stsm = tiled_copy_stsm.get_thread_slice(tid);
auto tXsX = thr_copy_ldsm.partition_S(s_in);
auto tXrX = make_tensor<Element>(shape(tXsX));
auto tXsX_out = thr_copy_stsm.partition_D(s_out);
cute::copy(tiled_copy_ldsm, tXsX, tXrX);
auto data = tXrX.data();
// size(tXrX) == 32
CUTLASS_PRAGMA_UNROLL
for (int n = 0; n < size(tXrX); n += 8) {
uint32_t *data_32bit = reinterpret_cast<uint32_t *>(&data[n]);
auto upper = data_32bit[0];
auto lower = data_32bit[1];
data_32bit[0] = __byte_perm(upper, lower, 0x6420);
data_32bit[1] = __byte_perm(upper, lower, 0x7531);
}
cute::copy(tiled_copy_stsm, tXrX, tXsX_out);
}
};
template <typename Ktraits, bool Is_causal, typename Seqlen_traits>
struct CollectiveMainloopFwd {
using Element = typename Ktraits::Element;
using TileShape_MNK = typename Ktraits::TileShape_MNK;
using ClusterShape = typename Ktraits::ClusterShape_MNK;
static constexpr int kStages = Ktraits::kStages;
static constexpr int kHeadDim = Ktraits::kHeadDim;
using GmemTiledCopyQ = cute::SM90_TMA_LOAD;
using GmemTiledCopyKV = decltype(cutlass::gemm::collective::detail::sm90_cluster_shape_to_tma_atom(shape<0>(ClusterShape{})));
using SmemLayoutQ = typename Ktraits::SmemLayoutQ;
using SmemLayoutK = typename Ktraits::SmemLayoutK;
using SmemLayoutV = typename Ktraits::SmemLayoutV;
using SmemLayoutVt = typename Ktraits::SmemLayoutVt;
using TMA_Q = decltype(make_tma_copy(
GmemTiledCopyQ{},
make_tensor(
make_gmem_ptr(static_cast<Element const*>(nullptr)),
repeat_like(typename Seqlen_traits::StrideT{}, int32_t(0)),
typename Seqlen_traits::StrideT{}
),
SmemLayoutQ{},
select<0, 2>(TileShape_MNK{}),
_1{})); // no mcast for Q
using TMA_K = decltype(make_tma_copy(
GmemTiledCopyKV{},
make_tensor(
make_gmem_ptr(static_cast<Element const*>(nullptr)),
repeat_like(typename Seqlen_traits::StrideT{}, int32_t(0)),
typename Seqlen_traits::StrideT{}
),
take<0, 2>(SmemLayoutK{}),
select<1, 2>(TileShape_MNK{}),
size<0>(ClusterShape{}))); // mcast along M mode for this N load, if any
// TMA_V may differ from TMA_K for fp8 kernel (e.g. swizzling mode)
using TMA_V = decltype(make_tma_copy(
GmemTiledCopyKV{},
make_tensor(
make_gmem_ptr(static_cast<Element const*>(nullptr)),
repeat_like(typename Seqlen_traits::StrideT{}, int32_t(0)),
typename Seqlen_traits::StrideT{}
),
take<0, 2>(SmemLayoutV{}),
select<1, 2>(TileShape_MNK{}),
size<0>(ClusterShape{}))); // mcast along M mode for this N load, if any
static constexpr int NumMmaThreads = size(typename Ktraits::TiledMma0{});
using MainloopPipeline = typename Ktraits::MainloopPipeline;
using MainloopPipelineNoTMA = typename Ktraits::MainloopPipelineNoTMA;
using PipelineParams = typename MainloopPipeline::Params;
using PipelineState = typename MainloopPipeline::PipelineState;
// Set the bytes transferred in this TMA transaction (may involve multiple issues)
static constexpr uint32_t TmaTransactionBytesQ = static_cast<uint32_t>(size(SmemLayoutQ{}) * cutlass::sizeof_bits_v<Element> / 8);
static constexpr uint32_t TmaTransactionBytesK = static_cast<uint32_t>(size(take<0, 2>(SmemLayoutK{})) * cutlass::sizeof_bits_v<Element> / 8);
// static constexpr bool UseSchedulerBarrier = kHeadDim <= 128;
static constexpr bool UseSchedulerBarrier =
cutlass::sizeof_bits_v<Element> == 8 ? kHeadDim >= 128
: kHeadDim <= 128;
// Host side kernel arguments
struct Arguments {
Element const* ptr_Q;
typename Seqlen_traits::LayoutT layout_Q;
Element const* ptr_K;
typename Seqlen_traits::LayoutT layout_K;
Element const* ptr_V;
typename Seqlen_traits::LayoutT layout_V;
float const softmax_scale_log2;
float const* descale_q_ptr;
float const* descale_k_ptr;
float const* descale_v_ptr;
};
// Device side kernel params
struct Params {
typename Seqlen_traits::LayoutT layout_Q;
typename Seqlen_traits::LayoutT layout_K;
typename Seqlen_traits::LayoutT layout_V;
cutlass::FastDivmod qhead_per_khead_divmod;
TMA_Q tma_load_Q;
TMA_K tma_load_K;
TMA_V tma_load_V;
float const softmax_scale_log2;
float const* descale_q_ptr;
float const* descale_k_ptr;
float const* descale_v_ptr;
};
static Params
to_underlying_arguments(Arguments const& args) {
Tensor mQ = make_tensor(make_gmem_ptr(args.ptr_Q), args.layout_Q);
TMA_Q tma_load_Q = make_tma_copy(
GmemTiledCopyQ{},
mQ,
SmemLayoutQ{},
select<0, 2>(TileShape_MNK{}),
_1{}); // no mcast for Q
Tensor mK = make_tensor(make_gmem_ptr(args.ptr_K), args.layout_K);
TMA_K tma_load_K = make_tma_copy(
GmemTiledCopyKV{},
mK,
SmemLayoutK{}(_, _, _0{}),
select<1, 2>(TileShape_MNK{}),
size<0>(ClusterShape{})); // mcast along M mode for this N load, if any
Tensor mV = make_tensor(make_gmem_ptr(args.ptr_V), args.layout_V);
TMA_V tma_load_V = make_tma_copy(
GmemTiledCopyKV{},
mV,
SmemLayoutV{}(_, _, _0{}),
select<1, 2>(TileShape_MNK{}),
size<0>(ClusterShape{})); // mcast along M mode for this N load, if any
return {args.layout_Q, args.layout_K, args.layout_V,
cutlass::FastDivmod(cute::ceil_div(get<2>(args.layout_Q.shape()), get<2>(args.layout_K.shape()))),
tma_load_Q, tma_load_K, tma_load_V,
args.softmax_scale_log2,
args.descale_q_ptr, args.descale_k_ptr, args.descale_v_ptr};
}
/// Issue Tma Descriptor Prefetch -- ideally from a single thread for best performance
CUTLASS_DEVICE
static void prefetch_tma_descriptors(Params const& mainloop_params) {
cute::prefetch_tma_descriptor(mainloop_params.tma_load_Q.get_tma_descriptor());
cute::prefetch_tma_descriptor(mainloop_params.tma_load_K.get_tma_descriptor());
cute::prefetch_tma_descriptor(mainloop_params.tma_load_V.get_tma_descriptor());
}
CUTLASS_DEVICE
int get_n_block_max(
Params const& mainloop_params, int m_block,
const Seqlen_traits& seqlen_traits_q,
const Seqlen_traits& seqlen_traits_k
) {
static constexpr int kBlockM = get<0>(TileShape_MNK{});
static constexpr int kBlockN = get<1>(TileShape_MNK{});
int const seqlen_q = Seqlen_traits::kUseVarSeqLen ? seqlen_traits_q.actual_seq_len : shape<0>(mainloop_params.layout_Q);
int const seqlen_k = Seqlen_traits::kUseVarSeqLen ? seqlen_traits_k.actual_seq_len : shape<0>(mainloop_params.layout_K);
int n_block_max = cute::ceil_div(seqlen_k, kBlockN);
if constexpr (Is_causal) {
n_block_max = std::min(n_block_max,
cute::ceil_div((m_block + 1) * kBlockM + seqlen_k - seqlen_q, kBlockN));
}
return n_block_max;
}
template <typename Scheduler, typename SharedStorage>
CUTLASS_DEVICE void
load(Params const& mainloop_params,
MainloopPipeline pipeline_k,
MainloopPipeline pipeline_v,
PipelineState& smem_pipe_write_k,
PipelineState& smem_pipe_write_v,
SharedStorage &shared_storage,
Scheduler& scheduler,
typename Scheduler::Params const& scheduler_params,
typename Scheduler::WorkTileInfo& work_tile_info,
cute::tuple<int32_t, int32_t, int32_t> block_coord,
int work_idx,
const Seqlen_traits& seqlen_traits_q,
const Seqlen_traits& seqlen_traits_k
) {
Tensor sQ = make_tensor(make_smem_ptr(shared_storage.smem_q.data()), SmemLayoutQ{});
Tensor sK = make_tensor(make_smem_ptr(shared_storage.smem_k.data()), SmemLayoutK{});
Tensor sV = make_tensor(make_smem_ptr(shared_storage.smem_v.data()), SmemLayoutV{});
Tensor mQ = mainloop_params.tma_load_Q.get_tma_tensor(mainloop_params.layout_Q.shape());
Tensor mK = mainloop_params.tma_load_K.get_tma_tensor(mainloop_params.layout_K.shape());
Tensor mV = mainloop_params.tma_load_V.get_tma_tensor(mainloop_params.layout_V.shape());
auto [m_block, bidh, bidb] = block_coord;
int bidh_kv = mainloop_params.qhead_per_khead_divmod.divide(bidh);
// Prepare the TMA loads
uint32_t block_rank_in_cluster = cute::block_rank_in_cluster();
constexpr uint32_t cluster_shape_x = get<0>(ClusterShape());
uint2 cluster_local_block_id = {block_rank_in_cluster % cluster_shape_x, block_rank_in_cluster / cluster_shape_x};
Tensor gQ = seqlen_traits_q.get_local_tile_tensor(
mQ, select<0, 2>(TileShape_MNK{}), bidh, bidb)(_, _, m_block); // (M, K)
Tensor gK = seqlen_traits_k.get_local_tile_tensor(
mK, select<1, 2>(TileShape_MNK{}), bidh_kv, bidb); // (N, K, _)
Tensor gV = seqlen_traits_k.get_local_tile_tensor(
mV, select<1, 2>(TileShape_MNK{}), bidh_kv, bidb); // (N, K, _)
Tensor sQ_x = make_tensor(sQ.data(), make_layout(sQ.layout(), Layout<_1>{}));
Tensor gQ_x = make_tensor(gQ.data(), make_layout(gQ.layout(), Layout<_1>{}));
auto [tQgQ, tQsQ] = tma_partition(mainloop_params.tma_load_Q, _0{}, Layout<_1>{},
group_modes<0, 2>(sQ_x), group_modes<0, 2>(gQ_x)); // (TMA), (TMA)
auto [tKgK, tKsK] = tma_partition(mainloop_params.tma_load_K, block_rank_in_cluster, Layout<ClusterShape>{},
group_modes<0, 2>(sK), group_modes<0, 2>(gK)); // (TMA, k), (TMA, PIPE)
auto [tVgV, tVsV] = tma_partition(mainloop_params.tma_load_V, block_rank_in_cluster, Layout<ClusterShape>{},
group_modes<0, 2>(sV), group_modes<0, 2>(gV)); // (TMA, k), (TMA, PIPE)
uint16_t mcast_mask_kv = 0;
if constexpr (cute::is_same_v<GmemTiledCopyKV, SM90_TMA_LOAD_MULTICAST>) {
auto block_layout = Layout<ClusterShape>{}; // (m,n) -> block_id
for (int m = 0; m < size<0>(block_layout); ++m) {
mcast_mask_kv |= (uint16_t(1) << block_layout(m, cluster_local_block_id.y, _0{}));
}
}
int n_block_max = get_n_block_max(mainloop_params, m_block, seqlen_traits_q, seqlen_traits_k);
int n_block = n_block_max - 1;
int lane_predicate = cute::elect_one_sync();
if (lane_predicate) {
pipeline_k.producer_acquire(smem_pipe_write_k);
copy(mainloop_params.tma_load_K.with(*pipeline_k.producer_get_barrier(smem_pipe_write_k), mcast_mask_kv),
tKgK(_, n_block), tKsK(_, smem_pipe_write_k.index()));
++smem_pipe_write_k;
}
// Wait for the MMA warpgroups to say that smem_q is ready
cutlass::arch::NamedBarrier::sync(NumMmaThreads + cutlass::NumThreadsPerWarp, static_cast<int>(FwdNamedBarriers::QueryEmpty) /*id*/);
if (lane_predicate) {
shared_storage.barrier_Q.arrive_and_expect_tx(TmaTransactionBytesQ);
copy(mainloop_params.tma_load_Q.with(reinterpret_cast<cutlass::arch::ClusterTransactionBarrier::ValueType&>(shared_storage.barrier_Q), 0 /*mcast_mask*/), tQgQ, tQsQ);
}
// Wait for warp 1 to signal that smem_v are ready and V can be copied from gmem
// Need ClusterBarrier, not just NamedBarrier. Otherwise we might have CTA 0 finishing the
// TMA store on O first, call TMA multicast load on V, before CTA 1 can finishing TMA store on O.
shared_storage.barrier_O.wait((work_idx + 1) % 2);
if (lane_predicate) {
// CUTLASS_PRAGMA_NO_UNROLL
#pragma unroll 2
for (; n_block > 0; --n_block) {
pipeline_k.producer_acquire(smem_pipe_write_k);
copy(mainloop_params.tma_load_K.with(*pipeline_k.producer_get_barrier(smem_pipe_write_k), mcast_mask_kv),
tKgK(_, n_block - 1), tKsK(_, smem_pipe_write_k.index()));
++smem_pipe_write_k;
pipeline_v.producer_acquire(smem_pipe_write_v);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write_v), mcast_mask_kv),
tVgV(_, n_block), tVsV(_, smem_pipe_write_v.index()));
++smem_pipe_write_v;
}
}
scheduler.prefetch_next_work(scheduler_params, work_tile_info);
if (lane_predicate) {
pipeline_v.producer_acquire(smem_pipe_write_v);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write_v), mcast_mask_kv),
tVgV(_, n_block), tVsV(_, smem_pipe_write_v.index()));
++smem_pipe_write_v;
}
scheduler.broadcast_next_work(work_tile_info);
}
template <typename Scheduler, typename SharedStorage>
CUTLASS_DEVICE void
load_fp8(Params const& mainloop_params,
MainloopPipeline pipeline_k,
MainloopPipeline pipeline_v,
MainloopPipelineNoTMA pipeline_vt,
PipelineState& smem_pipe_write,
PipelineState& smem_pipe_read,
SharedStorage &shared_storage,
Scheduler& scheduler,
typename Scheduler::Params const& scheduler_params,
typename Scheduler::WorkTileInfo& work_tile_info,
cute::tuple<int32_t, int32_t, int32_t> block_coord,
int work_idx,
const Seqlen_traits& seqlen_traits_q,
const Seqlen_traits& seqlen_traits_k
) {
using SmemLayoutTransposeV = typename Ktraits::SmemLayoutTransposeV;
using SmemLayoutTransposeVt = typename Ktraits::SmemLayoutTransposeVt;
Tensor sQ = make_tensor(make_smem_ptr(shared_storage.smem_q.data()), SmemLayoutQ{});
Tensor sK = make_tensor(make_smem_ptr(shared_storage.smem_k.data()), SmemLayoutK{});
Tensor sV = make_tensor(make_smem_ptr(shared_storage.smem_v.data()), SmemLayoutV{});
Tensor sV_divide = as_position_independent_swizzle_tensor(make_tensor(make_smem_ptr(shared_storage.smem_v.data()), SmemLayoutTransposeV{}));
Tensor sVt_divide = as_position_independent_swizzle_tensor(make_tensor(make_smem_ptr(shared_storage.smem_v_out.data()), SmemLayoutTransposeVt{}));
auto smem_transpose_V = SmemTransposeFp8_64x64();
auto do_transpose_V = [&](int stage) {
CUTLASS_PRAGMA_UNROLL
for (int j = 0; j < shape<2>(SmemLayoutTransposeV{}); ++j) {
CUTLASS_PRAGMA_UNROLL
for (int i = 0; i < shape<1>(SmemLayoutTransposeV{}); ++i) {
smem_transpose_V(flatten(sV_divide(_, i, j, stage)),
flatten(sVt_divide(_, i, j, stage)));
}
}
cutlass::arch::NamedBarrier::sync(cutlass::NumThreadsPerWarpGroup, static_cast<int>(FwdNamedBarriers::ProducerWG) /*id*/);
};
Tensor mQ = mainloop_params.tma_load_Q.get_tma_tensor(mainloop_params.layout_Q.shape());
Tensor mK = mainloop_params.tma_load_K.get_tma_tensor(mainloop_params.layout_K.shape());
Tensor mV = mainloop_params.tma_load_V.get_tma_tensor(mainloop_params.layout_V.shape());
auto [m_block, bidh, bidb] = block_coord;
int bidh_kv = mainloop_params.qhead_per_khead_divmod.divide(bidh);
// Prepare the TMA loads
uint32_t block_rank_in_cluster = cute::block_rank_in_cluster();
constexpr uint32_t cluster_shape_x = get<0>(ClusterShape());
uint2 cluster_local_block_id = {block_rank_in_cluster % cluster_shape_x, block_rank_in_cluster / cluster_shape_x};
Tensor gQ = seqlen_traits_q.get_local_tile_tensor(
mQ, select<0, 2>(TileShape_MNK{}), bidh, bidb)(_, _, m_block); // (M, K)
Tensor gK = seqlen_traits_k.get_local_tile_tensor(
mK, select<1, 2>(TileShape_MNK{}), bidh_kv, bidb); // (N, K, _)
Tensor gV = seqlen_traits_k.get_local_tile_tensor(
mV, select<1, 2>(TileShape_MNK{}), bidh_kv, bidb); // (N, K, _)
Tensor sQ_x = make_tensor(sQ.data(), make_layout(sQ.layout(), Layout<_1>{}));
Tensor gQ_x = make_tensor(gQ.data(), make_layout(gQ.layout(), Layout<_1>{}));
auto [tQgQ, tQsQ] = tma_partition(mainloop_params.tma_load_Q, _0{}, Layout<_1>{},
group_modes<0, 2>(sQ_x), group_modes<0, 2>(gQ_x)); // (TMA), (TMA)
auto [tKgK, tKsK] = tma_partition(mainloop_params.tma_load_K, block_rank_in_cluster, Layout<ClusterShape>{},
group_modes<0, 2>(sK), group_modes<0, 2>(gK)); // (TMA, k), (TMA, PIPE)
auto [tVgV, tVsV] = tma_partition(mainloop_params.tma_load_V, block_rank_in_cluster, Layout<ClusterShape>{},
group_modes<0, 2>(sV), group_modes<0, 2>(gV)); // (TMA, k), (TMA, PIPE)
uint16_t mcast_mask_kv = 0;
if constexpr (cute::is_same_v<GmemTiledCopyKV, SM90_TMA_LOAD_MULTICAST>) {
auto block_layout = Layout<ClusterShape>{}; // (m,n) -> block_id
for (int m = 0; m < size<0>(block_layout); ++m) {
mcast_mask_kv |= (uint16_t(1) << block_layout(m, cluster_local_block_id.y, _0{}));
}
}
int n_block_max = get_n_block_max(mainloop_params, m_block, seqlen_traits_q, seqlen_traits_k);
int n_block = n_block_max - 1;
int lane_predicate = cute::elect_one_sync();
int warp_idx_in_warpgroup = __shfl_sync(0xffffffff, (threadIdx.x / 32) % 4, 0);
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
pipeline_k.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_K.with(*pipeline_k.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tKgK(_, n_block), tKsK(_, smem_pipe_write.index()));
}
// Wait for the MMA warpgroups to say that smem_q is ready
// for fp8, change from NumThreadsPerWarp to NumThreadsPerWarpGroup
cutlass::arch::NamedBarrier::sync(NumMmaThreads + cutlass::NumThreadsPerWarpGroup, static_cast<int>(FwdNamedBarriers::QueryEmpty) /*id*/);
if constexpr(Is_causal) {
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
shared_storage.barrier_Q.arrive_and_expect_tx(TmaTransactionBytesQ);
copy(mainloop_params.tma_load_Q.with(reinterpret_cast<cutlass::arch::ClusterTransactionBarrier::ValueType&>(shared_storage.barrier_Q), 0 /*mcast_mask*/), tQgQ, tQsQ);
pipeline_v.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tVgV(_, n_block), tVsV(_, smem_pipe_write.index()));
}
shared_storage.barrier_O.wait((work_idx + 1) % 2);
CUTLASS_PRAGMA_UNROLL
for (int iter = 0; iter < kStages && n_block > 0; ++iter, --n_block) {
pipeline_v.consumer_wait(smem_pipe_read);
// pipeline_vt.producer_acquire(smem_pipe_write);
do_transpose_V(smem_pipe_read.index());
pipeline_vt.producer_commit(smem_pipe_write);
pipeline_v.consumer_release(smem_pipe_read);
++smem_pipe_write;
++smem_pipe_read;
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
pipeline_k.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_K.with(*pipeline_k.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tKgK(_, n_block-1), tKsK(_, smem_pipe_write.index()));
pipeline_v.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tVgV(_, n_block-1), tVsV(_, smem_pipe_write.index()));
}
}
#pragma unroll 2
for (; n_block > 0; --n_block) {
pipeline_v.consumer_wait(smem_pipe_read);
pipeline_vt.producer_acquire(smem_pipe_write);
do_transpose_V(smem_pipe_read.index());
pipeline_vt.producer_commit(smem_pipe_write);
pipeline_v.consumer_release(smem_pipe_read);
++smem_pipe_write;
++smem_pipe_read;
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
pipeline_k.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_K.with(*pipeline_k.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tKgK(_, n_block-1), tKsK(_, smem_pipe_write.index()));
pipeline_v.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tVgV(_, n_block-1), tVsV(_, smem_pipe_write.index()));
}
}
scheduler.prefetch_next_work(scheduler_params, work_tile_info);
scheduler.broadcast_next_work(work_tile_info);
pipeline_v.consumer_wait(smem_pipe_read);
if (n_block_max > kStages)
pipeline_vt.producer_acquire(smem_pipe_write);
do_transpose_V(smem_pipe_read.index());
pipeline_vt.producer_commit(smem_pipe_write);
pipeline_v.consumer_release(smem_pipe_read);
++smem_pipe_write;
++smem_pipe_read;
} else {
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
shared_storage.barrier_Q.arrive_and_expect_tx(TmaTransactionBytesQ);
copy(mainloop_params.tma_load_Q.with(reinterpret_cast<cutlass::arch::ClusterTransactionBarrier::ValueType&>(shared_storage.barrier_Q), 0 /*mcast_mask*/), tQgQ, tQsQ);
pipeline_v.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tVgV(_, n_block), tVsV(_, smem_pipe_write.index()));
}
// With fp8 kernel, smem_o is in union with smem_v_out,
// so could use NamedBarrier instead of ClusterBarrier.
// But, this doesn't appear to have any benefit.
shared_storage.barrier_O.wait((work_idx + 1) % 2);
pipeline_v.consumer_wait(smem_pipe_read);
// pipeline_vt.producer_acquire(smem_pipe_write);
do_transpose_V(smem_pipe_read.index());
pipeline_vt.producer_commit(smem_pipe_write);
pipeline_v.consumer_release(smem_pipe_read);
++smem_pipe_write;
++smem_pipe_read;
--n_block;
constexpr int extra_iterations = kStages - 1;
CUTLASS_PRAGMA_UNROLL
for (int iter = 0; iter < extra_iterations && n_block >= 0; ++iter) {
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
pipeline_k.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_K.with(*pipeline_k.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tKgK(_, n_block), tKsK(_, smem_pipe_write.index()));
pipeline_v.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tVgV(_, n_block), tVsV(_, smem_pipe_write.index()));
}
pipeline_v.consumer_wait(smem_pipe_read);
// pipeline_vt.producer_acquire(smem_pipe_write);
do_transpose_V(smem_pipe_read.index());
pipeline_vt.producer_commit(smem_pipe_write);
pipeline_v.consumer_release(smem_pipe_read);
++smem_pipe_write;
++smem_pipe_read;
--n_block;
}
// CUTLASS_PRAGMA_NO_UNROLL
#pragma unroll 2
for (; n_block >= 0; --n_block) {
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
pipeline_k.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_K.with(*pipeline_k.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tKgK(_, n_block), tKsK(_, smem_pipe_write.index()));
pipeline_v.producer_acquire(smem_pipe_write);
copy(mainloop_params.tma_load_V.with(*pipeline_v.producer_get_barrier(smem_pipe_write), mcast_mask_kv),
tVgV(_, n_block), tVsV(_, smem_pipe_write.index()));
}
pipeline_v.consumer_wait(smem_pipe_read);
pipeline_vt.producer_acquire(smem_pipe_write);
do_transpose_V(smem_pipe_read.index());
pipeline_vt.producer_commit(smem_pipe_write);
pipeline_v.consumer_release(smem_pipe_read);
++smem_pipe_write;
++smem_pipe_read;
}
// scheduler.prefetch_next_work(scheduler_params, work_tile_info);
// scheduler.broadcast_next_work(work_tile_info);
}
}
/// Perform a Producer Epilogue to prevent early exit of blocks in a Cluster
CUTLASS_DEVICE void
load_tail(MainloopPipeline pipeline_k, MainloopPipeline pipeline_v,
PipelineState& smem_pipe_write_k, PipelineState& smem_pipe_write_v) {
int lane_predicate = cute::elect_one_sync();
int warp_idx_in_warpgroup = __shfl_sync(0xffffffff, (threadIdx.x / 32) % 4, 0);
// Issue the epilogue waits
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
/* This helps avoid early exit of blocks in Cluster
* Waits for all stages to either be released (all Consumer UNLOCKs), or if the stage was never used
* then would just be acquired since the phase was still inverted from make_producer_start_state
*/
pipeline_k.producer_tail(smem_pipe_write_k);
pipeline_v.producer_tail(smem_pipe_write_v);
}
}
/// Perform a Producer Epilogue to prevent early exit of blocks in a Cluster
CUTLASS_DEVICE void
load_tail_one_write(MainloopPipeline pipeline_k, MainloopPipeline pipeline_v,
PipelineState& smem_pipe_write) {
int lane_predicate = cute::elect_one_sync();
int warp_idx_in_warpgroup = __shfl_sync(0xffffffff, (threadIdx.x / 32) % 4, 0);
// Issue the epilogue waits
if (warp_idx_in_warpgroup == 0 && lane_predicate) {
/* This helps avoid early exit of blocks in Cluster
* Waits for all stages to either be released (all Consumer UNLOCKs), or if the stage was never used
* then would just be acquired since the phase was still inverted from make_producer_start_state
*/
pipeline_k.producer_tail(smem_pipe_write);
pipeline_v.producer_tail(smem_pipe_write);
}
}
CUTLASS_DEVICE void
warp_scheduler_barrier_sync() {
if constexpr (UseSchedulerBarrier) {
cutlass::arch::NamedBarrier::sync(NumMmaThreads, static_cast<int>(FwdNamedBarriers::WarpSchedulerWG1) - 1 + cutlass::canonical_warp_group_idx() /*id*/);
}
}
CUTLASS_DEVICE void
warp_scheduler_barrier_arrive() {
if constexpr (!UseSchedulerBarrier) { return; }
static_assert(NumMmaThreads == 2 * cutlass::NumThreadsPerWarpGroup || NumMmaThreads == 3 * cutlass::NumThreadsPerWarpGroup);
if constexpr (NumMmaThreads == 2 * cutlass::NumThreadsPerWarpGroup) {
cutlass::arch::NamedBarrier::arrive(NumMmaThreads, static_cast<int>(FwdNamedBarriers::WarpSchedulerWG1) - 1 + (3 - cutlass::canonical_warp_group_idx()) /*id*/);
} else {
cutlass::arch::NamedBarrier::arrive(NumMmaThreads, static_cast<int>(FwdNamedBarriers::WarpSchedulerWG1) - 1 + (cutlass::canonical_warp_group_idx() <= 2 ? cutlass::canonical_warp_group_idx() + 1 : cutlass::canonical_warp_group_idx() + 1 - 3) /*id*/);
cutlass::arch::NamedBarrier::arrive(NumMmaThreads, static_cast<int>(FwdNamedBarriers::WarpSchedulerWG1) - 1 + (cutlass::canonical_warp_group_idx() <= 1 ? cutlass::canonical_warp_group_idx() + 2 : cutlass::canonical_warp_group_idx() + 2 - 3) /*id*/);
}
}
CUTLASS_DEVICE void
mma_init() {
// Tell producer (warp 0) that smem_q is ready
cutlass::arch::NamedBarrier::arrive(NumMmaThreads + Ktraits::NumProducerThreads, static_cast<int>(FwdNamedBarriers::QueryEmpty) /*id*/);
if constexpr (!UseSchedulerBarrier) { return; }
static_assert(NumMmaThreads == 2 * cutlass::NumThreadsPerWarpGroup || NumMmaThreads == 3 * cutlass::NumThreadsPerWarpGroup);
if (cutlass::canonical_warp_group_idx() > 1) {
cutlass::arch::NamedBarrier::arrive(NumMmaThreads, static_cast<int>(FwdNamedBarriers::WarpSchedulerWG1) - 1 + 1 /*id*/);
}
if constexpr (NumMmaThreads == 3 * cutlass::NumThreadsPerWarpGroup) {
if (cutlass::canonical_warp_group_idx() > 2) {
cutlass::arch::NamedBarrier::arrive(NumMmaThreads, static_cast<int>(FwdNamedBarriers::WarpSchedulerWG1) - 1 + 2 /*id*/);
}
}
}
template <typename SharedStorage, typename FrgTensorO, typename Softmax>
CUTLASS_DEVICE void
mma(Params const& mainloop_params,
MainloopPipeline pipeline_k,
MainloopPipeline pipeline_v,
PipelineState& smem_pipe_read_k,
PipelineState& smem_pipe_read_v,
FrgTensorO& tOrO,
Softmax& softmax,
int n_block_count,
int thread_idx,
int work_idx,
int m_block,
SharedStorage& shared_storage,
const Seqlen_traits& seqlen_traits_q,
const Seqlen_traits& seqlen_traits_k
) {
static_assert(is_rmem<FrgTensorO>::value, "O tensor must be rmem resident.");
static constexpr int kBlockM = get<0>(TileShape_MNK{});
static constexpr int kBlockN = get<1>(TileShape_MNK{});
Tensor sQ = make_tensor(make_smem_ptr(shared_storage.smem_q.data()), SmemLayoutQ{});
Tensor sK = make_tensor(make_smem_ptr(shared_storage.smem_k.data()), SmemLayoutK{});
Tensor sVt = make_tensor(make_smem_ptr(shared_storage.smem_v.data()), SmemLayoutVt{});
typename Ktraits::TiledMma0 tiled_mma0;
typename Ktraits::TiledMma1 tiled_mma1;
auto threadMma0 = tiled_mma0.get_thread_slice(thread_idx);
auto threadMma1 = tiled_mma1.get_thread_slice(thread_idx);
// Allocate "fragments/descriptors" for first matmul.
Tensor tSrQ = threadMma0.partition_fragment_A(sQ);
Tensor tSrK = threadMma0.partition_fragment_B(sK);
// Allocate "fragments/descriptors" for second matmul.
// Note: S becomes P.
Tensor tOrV = threadMma1.partition_fragment_B(sVt);
auto consumer_wait = [](auto& pipeline, auto& smem_pipe_read) {
auto barrier_token = pipeline.consumer_try_wait(smem_pipe_read);
pipeline.consumer_wait(smem_pipe_read, barrier_token);
};
tiled_mma1.accumulate_ = GMMA::ScaleOut::Zero;
int const seqlen_q = seqlen_traits_q.actual_seq_len;
int const seqlen_k = seqlen_traits_k.actual_seq_len;
int n_block = n_block_count - 1;
cutlass::ConsumerToken barrier_token = static_cast<cutlass::BarrierStatus>(shared_storage.barrier_Q.try_wait(work_idx % 2));
if (barrier_token == cutlass::BarrierStatus::WaitAgain) { shared_storage.barrier_Q.wait(work_idx % 2); }
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read_k);
warp_scheduler_barrier_sync();
flash::gemm</*zero_init=*/true, /*wg_wait=*/-1>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read_k.index()), tSrS);
warp_scheduler_barrier_arrive();
if (work_idx != 0) {
int lane_predicate = cute::elect_one_sync();
if (cutlass::canonical_warp_idx_sync() == Ktraits::kNWarps - 1 && lane_predicate) {
tma_store_wait<0>();
#pragma unroll
for (uint32_t cta_id = 0; cta_id < size(ClusterShape{}); ++cta_id) {
shared_storage.barrier_O.arrive(cta_id, lane_predicate);
}
}
}
warpgroup_wait<0>();
pipeline_k.consumer_release(smem_pipe_read_k);
++smem_pipe_read_k;
auto col_limit_causal = [&](int row, int n_block) {
return row + 1 + seqlen_k - n_block * kBlockN - seqlen_q + m_block * kBlockM;
};
{
Tensor cS = cute::make_identity_tensor(select<0, 1>(TileShape_MNK{}));
Tensor tScS = threadMma0.partition_C(cS);
#pragma unroll
for (int i = 0; i < size(tSrS); ++i) {
if constexpr (!Is_causal) { // Just masking based on col
if (int(get<1>(tScS(i))) >= int(seqlen_k - n_block * kBlockN)) { tSrS(i) = -INFINITY; }
} else { // mask based on both row and col
// using std::min is faster than doing col >= limit0 or col >= limit1
// Need to cast get<1>(tScS(i)) to (signed) int since by default it's unsigned, and the
// right hand side can be negative and might be converted to a very large unsigned integer.
if (int(get<1>(tScS(i))) >= std::min(seqlen_k - n_block * kBlockN,
col_limit_causal(int(get<0>(tScS(i))), n_block))) {
tSrS(i) = -INFINITY;
}
}
}
}
softmax.template online_softmax</*Is_first=*/true>(tSrS);
Tensor tOrP = make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs<typename Ktraits::TiledMma1>(tSrS.layout()));
Tensor scores_scale = make_fragment_like(softmax.row_max);
clear(scores_scale);
constexpr int n_masking_steps = !Is_causal ? 1 : cute::ceil_div(kBlockM, kBlockN) + 1;
// Only go through these if Is_causal, since n_masking_steps = 1 when !Is_causal
#pragma unroll
for (int masking_step = 0; masking_step < n_masking_steps - 1 && n_block > 0; ++masking_step, --n_block) {
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read_k);
warp_scheduler_barrier_sync();
flash::gemm</*zero_init=*/true, /*wg_wait=*/-1>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read_k.index()), tSrS);
if (masking_step > 0) { softmax.rescale_o(tOrO, scores_scale); }
consumer_wait(pipeline_v, smem_pipe_read_v);
flash::gemm</*zero_init=*/false, /*wg_wait=*/-1>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read_v.index()), tOrO);
warp_scheduler_barrier_arrive();
warpgroup_wait<1>();
pipeline_k.consumer_release(smem_pipe_read_k); // release K
Tensor cS = cute::make_identity_tensor(select<0, 1>(TileShape_MNK{}));
Tensor tScS = threadMma0.partition_C(cS);
#pragma unroll
for (int i = 0; i < size(tSrS); ++i) {
if (int(get<1>(tScS(i))) >= col_limit_causal(int(get<0>(tScS(i))), n_block - 1)) {
tSrS(i) = -INFINITY;
}
}
cute::copy(softmax.template max</*Is_first=*/false, /*Check_inf=*/true>(tSrS), scores_scale);
softmax.template online_softmax</*Is_first=*/false, /*Check_inf=*/true>(tSrS);
warpgroup_wait<0>();
pipeline_v.consumer_release(smem_pipe_read_v); // release V
++smem_pipe_read_k;
++smem_pipe_read_v;
cute::copy(make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs<typename Ktraits::TiledMma1>(tSrS.layout())), tOrP);
}
#pragma unroll 1
for (; n_block > 0; --n_block) {
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read_k);
warp_scheduler_barrier_sync();
flash::gemm</*zero_init=*/true, /*wg_wait=*/-1>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read_k.index()), tSrS);
softmax.rescale_o(tOrO, scores_scale);
consumer_wait(pipeline_v, smem_pipe_read_v);
flash::gemm</*zero_init=*/false, /*wg_wait=*/-1>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read_v.index()), tOrO);
warp_scheduler_barrier_arrive();
warpgroup_wait<1>();
pipeline_k.consumer_release(smem_pipe_read_k); // release K
// auto scores_scale = softmax.template max</*Is_first=*/false>(tSrS);
cute::copy(softmax.template max</*Is_first=*/false>(tSrS), scores_scale);
softmax.template online_softmax</*Is_first=*/false>(tSrS);
warpgroup_wait<0>();
pipeline_v.consumer_release(smem_pipe_read_v); // release V
++smem_pipe_read_k;
++smem_pipe_read_v;
// softmax.rescale_o(tOrO, scores_scale);
cute::copy(make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs<typename Ktraits::TiledMma1>(tSrS.layout())), tOrP);
}
// Tell warp 0 that smem_q is ready
cutlass::arch::NamedBarrier::arrive(NumMmaThreads + cutlass::NumThreadsPerWarp, static_cast<int>(FwdNamedBarriers::QueryEmpty) /*id*/);
softmax.rescale_o(tOrO, scores_scale);
consumer_wait(pipeline_v, smem_pipe_read_v);
flash::gemm</*zero_init=*/false, /*wg_wait=*/-1>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read_v.index()), tOrO);
cute::copy(softmax.template finalize</*Check_inf=*/Is_causal>(tSrS), scores_scale);
warpgroup_wait<0>();
pipeline_v.consumer_release(smem_pipe_read_v); // release V, otherwise producers will hang
++smem_pipe_read_v;
softmax.rescale_o(tOrO, scores_scale);
return;
}
template <bool Delay_V_release = false, typename SharedStorage, typename FrgTensorO, typename Softmax>
CUTLASS_DEVICE void
mma_fp8(Params const& mainloop_params,
MainloopPipeline pipeline_k,
MainloopPipelineNoTMA pipeline_vt,
PipelineState& smem_pipe_read,
PipelineState& smem_pipe_release,
FrgTensorO& tOrO,
Softmax& softmax,
int n_block_count,
int thread_idx,
int work_idx,
int m_block,
SharedStorage& shared_storage,
const Seqlen_traits& seqlen_traits_q,
const Seqlen_traits& seqlen_traits_k
) {
static_assert(is_rmem<FrgTensorO>::value, "O tensor must be rmem resident.");
static constexpr int kBlockM = get<0>(TileShape_MNK{});
static constexpr int kBlockN = get<1>(TileShape_MNK{});
Tensor sQ = make_tensor(make_smem_ptr(shared_storage.smem_q.data()), SmemLayoutQ{});
Tensor sK = make_tensor(make_smem_ptr(shared_storage.smem_k.data()), SmemLayoutK{});
Tensor sVt = make_tensor(make_smem_ptr(shared_storage.smem_v_out.data()), SmemLayoutVt{});
typename Ktraits::TiledMma0 tiled_mma0;
typename Ktraits::TiledMma1 tiled_mma1;
auto threadMma0 = tiled_mma0.get_thread_slice(thread_idx);
auto threadMma1 = tiled_mma1.get_thread_slice(thread_idx);
// Allocate "fragments/descriptors" for first matmul.
Tensor tSrQ = threadMma0.partition_fragment_A(sQ);
Tensor tSrK = threadMma0.partition_fragment_B(sK);
// Allocate "fragments/descriptors" for second matmul.
Tensor tOrV = threadMma1.partition_fragment_B(sVt);
auto consumer_wait = [](auto& pipeline, auto& smem_pipe_read) {
auto barrier_token = pipeline.consumer_try_wait(smem_pipe_read);
pipeline.consumer_wait(smem_pipe_read, barrier_token);
};
tiled_mma1.accumulate_ = GMMA::ScaleOut::Zero;
// workaround for fp8 only perf regression pending change to seqlen traits class
int const seqlen_q = Seqlen_traits::kUseVarSeqLen ? seqlen_traits_q.actual_seq_len : shape<0>(mainloop_params.layout_Q);
int const seqlen_k = Seqlen_traits::kUseVarSeqLen ? seqlen_traits_k.actual_seq_len : shape<0>(mainloop_params.layout_K);
int n_block = n_block_count - 1;
cutlass::ConsumerToken barrier_token = static_cast<cutlass::BarrierStatus>(shared_storage.barrier_Q.try_wait(work_idx % 2));
if (barrier_token == cutlass::BarrierStatus::WaitAgain) { shared_storage.barrier_Q.wait(work_idx % 2); }
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read);
warp_scheduler_barrier_sync();
flash::gemm</*zero_init=*/true, /*wg_wait=*/-1>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read.index()), tSrS);
if (work_idx != 0) {
int lane_predicate = cute::elect_one_sync();
if (cutlass::canonical_warp_idx_sync() == Ktraits::kNWarps - 1 && lane_predicate) {
tma_store_wait<0>();
#pragma unroll
for (uint32_t cta_id = 0; cta_id < size(ClusterShape{}); ++cta_id) {
shared_storage.barrier_O.arrive(cta_id, lane_predicate);
}
}
}
warpgroup_wait<0>();
warp_scheduler_barrier_arrive();
pipeline_k.consumer_release(smem_pipe_read);
auto col_limit_causal = [&](int row, int n_block) {
return row + 1 + seqlen_k - n_block * kBlockN - seqlen_q + m_block * kBlockM;
};
{
Tensor cS = cute::make_identity_tensor(select<0, 1>(TileShape_MNK{}));
Tensor tScS = threadMma0.partition_C(cS);
#pragma unroll
for (int i = 0; i < size(tSrS); ++i) {
if constexpr (!Is_causal) { // Just masking based on col
if (int(get<1>(tScS(i))) >= int(seqlen_k - n_block * kBlockN)) { tSrS(i) = -INFINITY; }
} else { // mask based on both row and col
if (int(get<1>(tScS(i))) >= std::min(seqlen_k - n_block * kBlockN,
col_limit_causal(int(get<0>(tScS(i))), n_block))) {
tSrS(i) = -INFINITY;
}
}
}
}
softmax.template online_softmax</*Is_first=*/true>(tSrS);
Tensor tOrP = make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs_fp8(tSrS.layout()));
permute_regs_A_to_C(tOrP);
Tensor scores_scale = make_fragment_like(softmax.row_max);
clear(scores_scale);
consumer_wait(pipeline_vt, smem_pipe_read);
flash::gemm</*zero_init=*/true, /*wg_wait=*/0>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read.index()), tOrO);
if constexpr(!Delay_V_release) { pipeline_vt.consumer_release(smem_pipe_read); }
++smem_pipe_read;
--n_block;
constexpr int extra_iterations = !Is_causal ? kStages - 1 : cute::ceil_div(kBlockM, kBlockN);
if constexpr(Is_causal) {
CUTLASS_PRAGMA_UNROLL
for (int iter = 0; iter < extra_iterations && n_block >= 0; ++iter, --n_block) {
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read);
warp_scheduler_barrier_sync();
flash::gemm</*zero_init=*/true, /*wg_wait=*/0>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read.index()), tSrS);
Tensor cS = cute::make_identity_tensor(select<0, 1>(TileShape_MNK{}));
Tensor tScS = threadMma0.partition_C(cS);
#pragma unroll
for (int i = 0; i < size(tSrS); ++i) {
if (int(get<1>(tScS(i))) >= col_limit_causal(int(get<0>(tScS(i))), n_block)) {
tSrS(i) = -INFINITY;
}
}
warp_scheduler_barrier_arrive();
pipeline_k.consumer_release(smem_pipe_read);
if constexpr(Delay_V_release) {
pipeline_vt.consumer_release(smem_pipe_release);
++smem_pipe_release;
}
consumer_wait(pipeline_vt, smem_pipe_read);
cute::copy(softmax.template max</*Is_first=*/false, /*Check_inf=*/true>(tSrS), scores_scale);
softmax.rescale_o(tOrO, scores_scale);
softmax.template online_softmax</*Is_first=*/false, /*Check_inf=*/true>(tSrS);
Tensor tOrP = make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs_fp8(tSrS.layout()));
permute_regs_A_to_C(tOrP);
flash::gemm</*zero_init=*/false, /*wg_wait=*/0>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read.index()), tOrO);
if constexpr(!Delay_V_release) { pipeline_vt.consumer_release(smem_pipe_read); }
++smem_pipe_read;
}
} else {
CUTLASS_PRAGMA_UNROLL
for (int iter = 0; iter < extra_iterations && n_block >= 0; ++iter, --n_block) {
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read);
if constexpr(Delay_V_release) {
pipeline_vt.consumer_release(smem_pipe_release);
++smem_pipe_release;
}
warp_scheduler_barrier_sync();
flash::gemm</*zero_init=*/true, /*wg_wait=*/0>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read.index()), tSrS);
warp_scheduler_barrier_arrive();
if constexpr(!Delay_V_release) { pipeline_k.consumer_release(smem_pipe_read); }
else { consumer_wait(pipeline_vt, smem_pipe_read); }
cute::copy(softmax.template max</*Is_first=*/false>(tSrS), scores_scale);
softmax.rescale_o(tOrO, scores_scale);
softmax.template online_softmax</*Is_first=*/false>(tSrS);
Tensor tOrP = make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs_fp8(tSrS.layout()));
permute_regs_A_to_C(tOrP);
if constexpr (Delay_V_release) { pipeline_k.consumer_release(smem_pipe_read); }
else { consumer_wait(pipeline_vt, smem_pipe_read); }
flash::gemm</*zero_init=*/false, /*wg_wait=*/0>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read.index()), tOrO);
if constexpr(!Delay_V_release) { pipeline_vt.consumer_release(smem_pipe_read); }
++smem_pipe_read;
}
}
if constexpr(Delay_V_release) {
warp_scheduler_barrier_sync();
CUTLASS_PRAGMA_NO_UNROLL
for (; n_block >= 0; --n_block) {
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read);
flash::gemm</*zero_init=*/true, /*wg_wait=*/0>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read.index()), tSrS);
warp_scheduler_barrier_arrive();
pipeline_k.consumer_release(smem_pipe_read);
pipeline_vt.consumer_release(smem_pipe_release);
cute::copy(softmax.template max</*Is_first=*/false>(tSrS), scores_scale);
softmax.rescale_o(tOrO, scores_scale);
softmax.template online_softmax</*Is_first=*/false>(tSrS);
Tensor tOrP = make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs_fp8(tSrS.layout()));
permute_regs_A_to_C(tOrP);
consumer_wait(pipeline_vt, smem_pipe_read);
flash::gemm</*zero_init=*/false, /*wg_wait=*/0>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read.index()), tOrO);
warp_scheduler_barrier_sync();
++smem_pipe_read;
++smem_pipe_release;
}
warp_scheduler_barrier_arrive();
pipeline_vt.consumer_release(smem_pipe_release);
++smem_pipe_release;
} else {
if constexpr (kHeadDim == 128) { warp_scheduler_barrier_sync(); }
CUTLASS_PRAGMA_NO_UNROLL
for (; n_block >= 0; --n_block) {
Tensor tSrS = partition_fragment_C(tiled_mma0, select<0, 1>(TileShape_MNK{}));
consumer_wait(pipeline_k, smem_pipe_read);
if constexpr (kHeadDim == 256) { warp_scheduler_barrier_sync(); }
flash::gemm</*zero_init=*/true, /*wg_wait=*/0>(tiled_mma0, tSrQ, tSrK(_, _, _, smem_pipe_read.index()), tSrS);
warp_scheduler_barrier_arrive();
pipeline_k.consumer_release(smem_pipe_read);
cute::copy(softmax.template max</*Is_first=*/false>(tSrS), scores_scale);
softmax.rescale_o(tOrO, scores_scale);
softmax.template online_softmax</*Is_first=*/false>(tSrS);
Tensor tOrP = make_tensor(convert_type<Element>(tSrS).data(), convert_layout_acc_Aregs_fp8(tSrS.layout()));
permute_regs_A_to_C(tOrP);
consumer_wait(pipeline_vt, smem_pipe_read);
if constexpr (kHeadDim == 128) { warp_scheduler_barrier_sync(); }
flash::gemm</*zero_init=*/false, /*wg_wait=*/0>(tiled_mma1, tOrP, tOrV(_, _, _, smem_pipe_read.index()), tOrO);
pipeline_vt.consumer_release(smem_pipe_read);
++smem_pipe_read;
}
if constexpr (kHeadDim == 128) { warp_scheduler_barrier_arrive(); }
}
cutlass::arch::NamedBarrier::arrive(NumMmaThreads + cutlass::NumThreadsPerWarpGroup, static_cast<int>(FwdNamedBarriers::QueryEmpty) /*id*/);
cute::copy(softmax.template finalize</*Check_inf=*/Is_causal>(tSrS, shared_storage.descale_v), scores_scale);
softmax.rescale_o(tOrO, scores_scale);
return;
}
};
} // namespace flash