Use xor transform to implement Q/K Lds descriptor for kKpack == 8 cases

This commit is contained in:
Qianfeng Zhang
2025-08-21 13:59:32 +00:00
parent 19fc2a9051
commit d4f43f0653

View File

@@ -178,7 +178,7 @@ struct HstuAttentionFwdPipelineQRKSVSDefaultPolicy
{
static_assert(kKVector == kKPack);
return kKPerBlock * kNPerBlock + kKPerBlock;
return kKPerBlock * kNPerBlock;
}
else
{
@@ -220,18 +220,47 @@ struct HstuAttentionFwdPipelineQRKSVSDefaultPolicy
{
static_assert(kKVector == kKPack);
using QDataType = remove_cvref_t<typename Problem::QKVDataType>;
constexpr index_t DataTypeSize = sizeof(QDataType);
// 128 contiguous bytes mapped to 32 banks with each bank 4 contiguous bytes
constexpr auto MLdsLayer =
(32 * 4 / kKPerBlock / DataTypeSize) < 1 ? 1 : (32 * 4 / kKPerBlock / DataTypeSize);
constexpr auto q_lds_block_desc_0 = make_naive_tensor_descriptor(
make_tuple(number<kKPerBlock / kKPack>{}, number<kMPerBlock>{}, number<kKPack>{}),
make_tuple(number<kMPerBlock * kKPack + kKPack>{}, number<kKPack>{}, number<1>{}),
make_tuple(number<kMPerBlock / MLdsLayer>{},
number<kKPerBlock / kKPack * MLdsLayer>{},
number<kKPack>{}),
make_tuple(number<kKPerBlock * MLdsLayer>{}, number<kKPack>{}, number<1>{}),
number<kKPack>{},
number<1>{});
constexpr auto q_lds_block_desc = transform_tensor_descriptor(
constexpr auto q_lds_block_desc_permuted = transform_tensor_descriptor(
q_lds_block_desc_0,
make_tuple(make_pass_through_transform(number<kMPerBlock>{}),
make_merge_transform(
make_tuple(
make_xor_transform(make_tuple(number<kMPerBlock / MLdsLayer>{},
number<kKPerBlock / kKPack * MLdsLayer>{})),
make_pass_through_transform(number<kKPack>{})),
make_tuple(sequence<0, 1>{}, sequence<2>{}),
make_tuple(sequence<0, 1>{}, sequence<2>{}));
constexpr auto q_lds_block_desc_k0_mldslayer_m_k1 = transform_tensor_descriptor(
q_lds_block_desc_permuted,
make_tuple(make_pass_through_transform(number<kMPerBlock / MLdsLayer>{}),
make_unmerge_transform(
make_tuple(number<kKPerBlock / kKPack>{}, number<MLdsLayer>{})),
make_pass_through_transform(number<kKPack>{})),
make_tuple(sequence<0>{}, sequence<1>{}, sequence<2>{}),
make_tuple(sequence<0>{}, sequence<1, 2>{}, sequence<3>{}));
constexpr auto q_lds_block_desc = transform_tensor_descriptor(
q_lds_block_desc_k0_mldslayer_m_k1,
make_tuple(make_merge_transform_v3_division_mod(
make_tuple(number<kMPerBlock / MLdsLayer>{}, number<MLdsLayer>{})),
make_merge_transform_v3_division_mod(
make_tuple(number<kKPerBlock / kKPack>{}, number<kKPack>{}))),
make_tuple(sequence<1>{}, sequence<0, 2>{}),
make_tuple(sequence<0, 2>{}, sequence<1, 3>{}),
make_tuple(sequence<0>{}, sequence<1>{}));
return q_lds_block_desc;
@@ -310,31 +339,55 @@ struct HstuAttentionFwdPipelineQRKSVSDefaultPolicy
{
static_assert(kKVector == kKPack);
constexpr index_t KSingleSmemElementSpaceSize = kKPerBlock * kNPerBlock + kKPerBlock;
using KDataType = remove_cvref_t<typename Problem::QKVDataType>;
static_assert(KSingleSmemElementSpaceSize == GetKSingleSmemElementSpaceSize<Problem>());
constexpr index_t DataTypeSize = sizeof(KDataType);
constexpr index_t SingleSmemElementSpaceSize = GetSingleSmemElementSpaceSize<Problem>();
// 128 contiguous bytes mapped to 32 banks with each bank 4 contiguous bytes
constexpr auto NLdsLayer =
(32 * 4 / kKPerBlock / DataTypeSize) < 1 ? 1 : (32 * 4 / kKPerBlock / DataTypeSize);
constexpr auto k_lds_block_desc_0 =
make_naive_tensor_descriptor(make_tuple(number<NumKLdsBuffers>{},
number<kKPerBlock / kKPack>{},
number<kNPerBlock>{},
number<kNPerBlock / NLdsLayer>{},
number<kKPerBlock / kKPack * NLdsLayer>{},
number<kKPack>{}),
make_tuple(number<SingleSmemElementSpaceSize>{},
number<kNPerBlock * kKPack + kKPack>{},
make_tuple(number<kKPerBlock * kNPerBlock>{},
number<kKPerBlock * NLdsLayer>{},
number<kKPack>{},
number<1>{}),
number<kKPack>{},
number<1>{});
constexpr auto k_lds_block_desc = transform_tensor_descriptor(
constexpr auto k_lds_block_desc_permuted = transform_tensor_descriptor(
k_lds_block_desc_0,
make_tuple(make_merge_transform(
make_tuple(number<NumKLdsBuffers>{}, number<kNPerBlock>{})),
make_merge_transform(
make_tuple(number<kKPerBlock / kKPack>{}, number<kKPack>{}))),
make_tuple(sequence<0, 2>{}, sequence<1, 3>{}),
make_tuple(
make_pass_through_transform(number<NumKLdsBuffers>{}),
make_xor_transform(make_tuple(number<kNPerBlock / NLdsLayer>{},
number<kKPerBlock / kKPack * NLdsLayer>{})),
make_pass_through_transform(number<kKPack>{})),
make_tuple(sequence<0>{}, sequence<1, 2>{}, sequence<3>{}),
make_tuple(sequence<0>{}, sequence<1, 2>{}, sequence<3>{}));
constexpr auto k_lds_block_desc_k0_nldslayer_n_k1 = transform_tensor_descriptor(
k_lds_block_desc_permuted,
make_tuple(make_pass_through_transform(number<NumKLdsBuffers>{}),
make_pass_through_transform(number<kNPerBlock / NLdsLayer>{}),
make_unmerge_transform(
make_tuple(number<kKPerBlock / kKPack>{}, number<NLdsLayer>{})),
make_pass_through_transform(number<kKPack>{})),
make_tuple(sequence<0>{}, sequence<1>{}, sequence<2>{}, sequence<3>{}),
make_tuple(sequence<0>{}, sequence<1>{}, sequence<2, 3>{}, sequence<4>{}));
constexpr auto k_lds_block_desc = transform_tensor_descriptor(
k_lds_block_desc_k0_nldslayer_n_k1,
make_tuple(
make_merge_transform_v3_division_mod(
make_tuple(number<kNPerBlock / NLdsLayer>{}, number<NLdsLayer>{})),
make_merge_transform_v3_division_mod(make_tuple(number<NumKLdsBuffers>{},
number<kKPerBlock / kKPack>{},
number<kKPack>{}))),
make_tuple(sequence<1, 3>{}, sequence<0, 2, 4>{}),
make_tuple(sequence<0>{}, sequence<1>{}));
return k_lds_block_desc;