vllm/csrc/quantization/gptq_allspark/allspark_qgemm_w8a16.cu

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#include "allspark_utils.cuh"
#include <torch/all.h>
#include "core/registration.h"
#include <cublas_v2.h>
at::Tensor as_g_workspace;
#if defined(__CUDA_ARCH__) && __CUDA_ARCH__ < 800
torch::Tensor allspark_w8a16_gemm(
torch::Tensor const& a, torch::Tensor const& b_qweight,
torch::Tensor const& b_scales, c10::optional<torch::Tensor> const& b_qzeros,
int64_t n, int64_t group_size, int64_t sm_count, int64_t sm_version,
int64_t CUBLAS_M_THRESHOLD, bool has_zp, bool n32k16_reorder) {
TORCH_CHECK_NOT_IMPLEMENTED(
false, "allspark_w8a16_gemm(..) requires CUDA_ARCH >= 8.0");
return torch::empty({1, 1});
}
#else
namespace allspark {
/*
* GemmTile manage data movement from Global Memory to Shared Memory
* requiring N % 8 == 0 K % 16 == 0 by loading uint
* BN is obtained by padding the original N to a multiple of 32
* weight B is rearranged as N32K16 order,
* i.e. a initial data block of size 32(n)x16(k) is reordered as n8k4n4k4
* in order to put data loaded by the same thread of 32x16 data block together
* continuously (see
* https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#matrix-fragments-for-mma-m16n8k16-with-floating-point-type)
*/
template <typename FType, typename QType, int Mtile, int Ntile, int NStage,
int BLOCK>
struct GmemTile_W8A16_PerC_MtilexNtilex32_multistage_SM8x_SplitK {
// element num loaded by a LDG inst.
static constexpr int LDG_ELEMENT_CNT_A = 8;
static constexpr int LDG_ELEMENT_CNT_B = 16;
static constexpr int WARP_SIZE = 32;
static constexpr int M_SIZE_ONE_LOAD = (BLOCK * LDG_ELEMENT_CNT_A) / 32;
static constexpr int N_SIZE_ONE_LOAD = (BLOCK * LDG_ELEMENT_CNT_B) / 32;
__device__ GmemTile_W8A16_PerC_MtilexNtilex32_multistage_SM8x_SplitK(
const SM8x_GEMM_W8A16_Splitk_Params<FType, QType>& k_params,
const uint32_t& A_smem_addr, const uint32_t& BQ_smem_addr,
const uint32_t& A_stage_stride, const uint32_t& BQ_stage_stride)
: params(k_params),
A_smem_base_addr(A_smem_addr),
BQ_smem_base_addr(BQ_smem_addr),
A_smem_stage_stride(A_stage_stride),
BQ_smem_stage_stride(BQ_stage_stride) {
this_block_A_base_ptr = params.A_ptr + blockIdx.x * Mtile * params.K +
blockIdx.z * params.SplitK;
// here B is rearranged as N32K16 order, i.e. 4 continuous N-direction
// 8(N)x16(K) size data blocks are packed together
this_block_B_base_ptr = params.B_ptr + blockIdx.y * Ntile * params.K +
blockIdx.z * params.SplitK * 4;
const auto lane_id = threadIdx.x % WARP_SIZE;
// For matrix A, a block load/store Mtile(row) x 32(col) elements in
// multiple iters, 8x4 warp load/store 8(row) x 32(col) elements per iter
const auto Aldg_row_base_idx = threadIdx.x / 4;
Aldg_col_idx = (threadIdx.x % 4) * LDG_ELEMENT_CNT_A;
const int Aldg_base_offset = Aldg_row_base_idx * params.K + Aldg_col_idx;
// For matrix B, a block load/store elements of (Ntile / 4) row x 128 col
// elements of N32K16 packing in multiple iters, 4x8 warp load/store 4(row)
// * 128(col) per iter
Bldg_col_idx = (threadIdx.x % 8) * LDG_ELEMENT_CNT_B;
const auto Bldg_row_base_idx = threadIdx.x / 8;
const int Bldg_base_offset =
Bldg_row_base_idx * params.K * 4 + Bldg_col_idx;
this_block_A_base_ptr += Aldg_base_offset;
this_block_B_base_ptr += Bldg_base_offset;
const int sts_a_base_offset =
(threadIdx.x / 4) * 32 +
((lane_id % 4) ^ ((lane_id / 4) % 4) ^ ((lane_id / 4) / 4)) *
LDG_ELEMENT_CNT_A;
const int sts_bq_base_offset =
Bldg_row_base_idx * 32 * 4 +
((threadIdx.x % 8) ^ (((threadIdx.x / 8) % 2) * 4)) * LDG_ELEMENT_CNT_B;
A_smem_base_addr += sts_a_base_offset * sizeof(FType);
BQ_smem_base_addr += sts_bq_base_offset * sizeof(uint8_t);
A_ldg_guard = 0;
B_ldg_guard = 0;
#pragma unroll
for (int i = 0; i < (Mtile + M_SIZE_ONE_LOAD - 1) / M_SIZE_ONE_LOAD; ++i) {
auto m_idx = blockIdx.x * Mtile + Aldg_row_base_idx + i * M_SIZE_ONE_LOAD;
if (m_idx < params.M) {
A_ldg_guard |= (1u << i);
}
}
const int N_padded = (params.N + 31) / 32 * 32;
#pragma unroll
for (int i = 0; i < (Ntile + N_SIZE_ONE_LOAD - 1) / N_SIZE_ONE_LOAD; ++i) {
auto n_idx = blockIdx.y * Ntile + (Bldg_row_base_idx / 8) * 32 +
i * N_SIZE_ONE_LOAD;
if (n_idx < N_padded) {
B_ldg_guard |= (1u << i);
}
}
}
__device__ void ldgsts_first_ktiles(const int& first_k_tile,
const int& k_tiles) {
// load first k_tile
// load A
const int A_src_size = Aldg_col_idx < first_k_tile ? 16 : 0;
#pragma unroll
for (int i = 0; i < (Mtile + M_SIZE_ONE_LOAD - 1) / M_SIZE_ONE_LOAD; ++i) {
cp_async<16>(
A_smem_base_addr + (i * M_SIZE_ONE_LOAD * 32) * sizeof(FType),
this_block_A_base_ptr + i * M_SIZE_ONE_LOAD * params.K, A_src_size,
(A_ldg_guard & (1u << i)) != 0);
}
// load B
const int B_src_size = (Bldg_col_idx / 4) < first_k_tile ? 16 : 0;
#pragma unroll
for (int i = 0; i < (Ntile + N_SIZE_ONE_LOAD - 1) / N_SIZE_ONE_LOAD; ++i) {
cp_async<16>(
BQ_smem_base_addr + (i * N_SIZE_ONE_LOAD * 32) * sizeof(uint8_t),
this_block_B_base_ptr + i * N_SIZE_ONE_LOAD * params.K, B_src_size,
(B_ldg_guard & (1u << i)) != 0);
}
cp_async_commit_group();
this_block_A_base_ptr += first_k_tile;
this_block_B_base_ptr += (first_k_tile * 4);
// load second to (N-stage - 1) k_tiles
for (int stage_idx = 1; stage_idx < NStage - 1; ++stage_idx) {
if (stage_idx < k_tiles) {
#pragma unroll
for (int i = 0; i < (Mtile + M_SIZE_ONE_LOAD - 1) / M_SIZE_ONE_LOAD;
++i) {
cp_async<16>(A_smem_base_addr + stage_idx * A_smem_stage_stride +
(i * M_SIZE_ONE_LOAD * 32) * sizeof(FType),
this_block_A_base_ptr + i * M_SIZE_ONE_LOAD * params.K,
16, (A_ldg_guard & (1u << i)) != 0);
}
#pragma unroll
for (int i = 0; i < (Ntile + N_SIZE_ONE_LOAD - 1) / N_SIZE_ONE_LOAD;
++i) {
cp_async<16>(BQ_smem_base_addr + stage_idx * BQ_smem_stage_stride +
(i * N_SIZE_ONE_LOAD * 32) * sizeof(uint8_t),
this_block_B_base_ptr + i * N_SIZE_ONE_LOAD * params.K,
16, (B_ldg_guard & (1u << i)) != 0);
}
this_block_A_base_ptr += 32;
this_block_B_base_ptr += (32 * 4);
}
cp_async_commit_group();
}
}
__device__ void ldgsts(const int& sts_stage_idx) {
const int a_stage_offset = sts_stage_idx * A_smem_stage_stride;
const int bq_stage_offset = sts_stage_idx * BQ_smem_stage_stride;
#pragma unroll
for (int i = 0; i < (Mtile + M_SIZE_ONE_LOAD - 1) / M_SIZE_ONE_LOAD; ++i) {
cp_async<16>(A_smem_base_addr + a_stage_offset +
(i * M_SIZE_ONE_LOAD * 32) * sizeof(FType),
this_block_A_base_ptr + i * M_SIZE_ONE_LOAD * params.K, 16,
(A_ldg_guard & (1u << i)) != 0);
}
#pragma unroll
for (int i = 0; i < (Ntile + N_SIZE_ONE_LOAD - 1) / N_SIZE_ONE_LOAD; ++i) {
cp_async<16>(BQ_smem_base_addr + bq_stage_offset +
(i * N_SIZE_ONE_LOAD * 32) * sizeof(uint8_t),
this_block_B_base_ptr + i * N_SIZE_ONE_LOAD * params.K, 16,
(B_ldg_guard & (1u << i)) != 0);
}
cp_async_commit_group();
this_block_A_base_ptr += 32;
this_block_B_base_ptr += (32 * 4);
}
const FType* this_block_A_base_ptr = nullptr;
const QType* this_block_B_base_ptr = nullptr;
int Aldg_col_idx;
int Bldg_col_idx;
uint32_t A_ldg_guard;
uint32_t B_ldg_guard;
uint32_t A_smem_base_addr, BQ_smem_base_addr;
const uint32_t A_smem_stage_stride, BQ_smem_stage_stride;
const SM8x_GEMM_W8A16_Splitk_Params<FType, QType>& params;
};
/*
* requiring N % 8 == 0
*/
template <typename FType, typename QType, int Mtile, int Ntile, int BLOCK,
bool EnableFuse, bool has_zp>
struct ComputeTile_W8A16_PerC_MtilexNtilex32_multistage_SM8x_SplitK {
static constexpr int WARP_SIZE = 32;
static constexpr int WARP_CNT = BLOCK / WARP_SIZE;
static constexpr int WARP_NTILE = Ntile / WARP_CNT;
static constexpr int WARP_NITER = WARP_NTILE / 8; // hmma16816
static_assert(WARP_NTILE == 32 or WARP_NTILE == 64,
"now only support WARP_NTILE = 32 or 64!");
__device__ ComputeTile_W8A16_PerC_MtilexNtilex32_multistage_SM8x_SplitK(
const SM8x_GEMM_W8A16_Splitk_Params<FType, QType>& k_params,
const uint32_t& A_smem_addr, const uint32_t& BQ_smem_addr,
const uint32_t& A_stage_stride, const uint32_t& BQ_stage_stride)
: params(k_params),
A_smem_base_addr(A_smem_addr),
BQ_smem_base_addr(BQ_smem_addr),
A_smem_stage_stride(A_stage_stride),
BQ_smem_stage_stride(BQ_stage_stride) {
warp_id = threadIdx.x / WARP_SIZE;
lane_id = threadIdx.x % WARP_SIZE;
load_a_base_offset[0] =
(lane_id % 16) * 32 +
((lane_id / 16) ^ (lane_id % 4) ^ ((lane_id / 4) % 2)) * 8;
load_a_base_offset[1] =
(lane_id % 16) * 32 +
((lane_id / 16 + 2) ^ (lane_id % 4) ^ ((lane_id / 4) % 2)) * 8;
load_b_base_offset[0] =
(lane_id / 4 + warp_id * (WARP_NTILE / 4)) * 32 * 4 +
(lane_id % 4) * 16 + ((lane_id / 4) % 2) * 16 * 4;
load_b_base_offset[1] =
(lane_id / 4 + warp_id * (WARP_NTILE / 4)) * 32 * 4 +
(lane_id % 4) * 16 + (((lane_id / 4) % 2) ^ 1) * 16 * 4;
sts_c_base_offset = warp_id * Mtile * WARP_NTILE +
(lane_id / 4) * WARP_NTILE + (lane_id % 4) * 2;
if (EnableFuse) {
this_block_C_base_ptr =
params.C_ptr + blockIdx.x * Mtile * params.N + blockIdx.y * Ntile;
} else {
this_block_C_base_ptr =
params.C_split_ptr + blockIdx.z * params.M * params.N +
blockIdx.x * Mtile * params.N + blockIdx.y * Ntile;
}
int store_thds_in_row = WARP_NTILE / 8;
store_c_row_base_idx = lane_id / store_thds_in_row;
store_c_col_idx = warp_id * WARP_NTILE + (lane_id % store_thds_in_row) * 8;
store_c_base_offset = store_c_row_base_idx * params.N + store_c_col_idx;
#pragma unroll
for (int i = 0; i < Mtile / 16; ++i) {
#pragma unroll
for (int j = 0; j < WARP_NITER; ++j) {
#pragma unroll
for (int k = 0; k < 4; ++k) {
C_frag[i][j][k] = 0.f;
}
}
}
params_n_idx =
blockIdx.y * Ntile + warp_id * WARP_NTILE + (lane_id / 4) * 4;
}
__device__ void lds(const int& smem_stage_idx, const int& reg_buf_idx,
const int& k_phase_idx) {
uint32_t A_smem_addr =
A_smem_base_addr + A_smem_stage_stride * smem_stage_idx;
uint32_t B_smem_addr =
BQ_smem_base_addr + BQ_smem_stage_stride * smem_stage_idx;
#pragma unroll
for (int i = 0; i < Mtile / 16; ++i) {
ldsm_4(A_frag[reg_buf_idx][i][0], A_frag[reg_buf_idx][i][1],
A_frag[reg_buf_idx][i][2], A_frag[reg_buf_idx][i][3],
A_smem_addr + (load_a_base_offset[k_phase_idx] + i * 16 * 32) *
sizeof(FType));
}
#pragma unroll
for (int i = 0; i < WARP_NTILE / 32; ++i) {
lds128(BQ_frag[reg_buf_idx][4 * i + 0], BQ_frag[reg_buf_idx][4 * i + 1],
BQ_frag[reg_buf_idx][4 * i + 2], BQ_frag[reg_buf_idx][4 * i + 3],
B_smem_addr + (load_b_base_offset[k_phase_idx] + i * 32 * 32) *
sizeof(uint8_t));
}
// dequant B
#pragma unroll
for (int i = 0; i < WARP_NITER / 2; ++i) {
cvt_8bx4_to_16bx4_bias128(BQ_frag[reg_buf_idx][2 * i],
BF_frag[reg_buf_idx][2 * i]);
if (has_zp) {
BF_frag[reg_buf_idx][2 * i][0] =
__hsub2(BF_frag[reg_buf_idx][2 * i][0], num2num2(B_zero[i].x));
BF_frag[reg_buf_idx][2 * i][1] =
__hsub2(BF_frag[reg_buf_idx][2 * i][1], num2num2(B_zero[i].x));
}
BF_frag[reg_buf_idx][2 * i][0] =
__hmul2(BF_frag[reg_buf_idx][2 * i][0], num2num2(B_scale[i].x));
BF_frag[reg_buf_idx][2 * i][1] =
__hmul2(BF_frag[reg_buf_idx][2 * i][1], num2num2(B_scale[i].x));
cvt_8bx4_to_16bx4_bias128(BQ_frag[reg_buf_idx][2 * i + 1],
BF_frag[reg_buf_idx][2 * i + 1]);
if (has_zp) {
BF_frag[reg_buf_idx][2 * i + 1][0] =
__hsub2(BF_frag[reg_buf_idx][2 * i + 1][0], num2num2(B_zero[i].y));
BF_frag[reg_buf_idx][2 * i + 1][1] =
__hsub2(BF_frag[reg_buf_idx][2 * i + 1][1], num2num2(B_zero[i].y));
}
BF_frag[reg_buf_idx][2 * i + 1][0] =
__hmul2(BF_frag[reg_buf_idx][2 * i + 1][0], num2num2(B_scale[i].y));
BF_frag[reg_buf_idx][2 * i + 1][1] =
__hmul2(BF_frag[reg_buf_idx][2 * i + 1][1], num2num2(B_scale[i].y));
}
}
__device__ void ldg_params() {
const int N_padded = (params.N + 31) / 32 * 32;
// load B scale and zero_point
#pragma unroll
for (int i = 0; i < WARP_NTILE / 32; ++i) {
ldg64_ca(B_scale[2 * i + 0], B_scale[2 * i + 1],
params.B_scale_ptr + params_n_idx + i * 32,
(params_n_idx + i * 32) < N_padded);
if (has_zp) {
ldg64_ca(B_zero[2 * i + 0], B_zero[2 * i + 1],
params.B_zero_ptr + params_n_idx + i * 32,
(params_n_idx + i * 32) < N_padded);
}
}
}
__device__ void mma(const int& reg_buf_idx) {
#pragma unroll
for (int m_idx = 0; m_idx < Mtile / 16; ++m_idx) {
#pragma unroll
for (int n_idx = 0; n_idx < WARP_NITER; ++n_idx) {
hmma16816_f32<FType>(
C_frag[m_idx][n_idx], A_frag[reg_buf_idx][m_idx],
reinterpret_cast<uint32_t(&)[2]>(BF_frag[reg_buf_idx][n_idx]));
}
}
}
__device__ void fused_splitk_reduce() {
// need splitk-reduce if enable splitk
if (gridDim.z > 1) {
auto blk_red_idx = blockIdx.x * gridDim.y + blockIdx.y;
// Wait for all previous blocks in the splitk direction to accumulate the
// results into C_tmp
if (threadIdx.x == 0) {
uint32_t* red_count_ptr = params.red_count_ptr + blk_red_idx;
uint32_t count;
do {
// make sure the ld.cg inside the do-wile loop
__threadfence_block();
asm volatile("ld.global.cg.b32 %0, [%1];"
: "=r"(count)
: "l"(red_count_ptr));
} while (count != blockIdx.z);
}
__syncthreads();
auto C_tmp_base_offset = blk_red_idx * Mtile * Ntile + threadIdx.x * 4;
if (blockIdx.z != 0) {
// expecting that temporary register here reuses the previous A&B frag
// register
float temp_frag[Mtile / 16][WARP_NITER][4];
#pragma unroll
for (int m_idx = 0; m_idx < Mtile / 16; ++m_idx) {
#pragma unroll
for (int n_idx = 0; n_idx < WARP_NITER; ++n_idx) {
int offset =
C_tmp_base_offset + (m_idx * WARP_NITER + n_idx) * BLOCK * 4;
*reinterpret_cast<int4*>(temp_frag[m_idx][n_idx]) =
*reinterpret_cast<int4*>(params.C_tmp_ptr + offset);
}
}
#pragma unroll
for (int m_idx = 0; m_idx < Mtile / 16; ++m_idx) {
#pragma unroll
for (int n_idx = 0; n_idx < WARP_NITER; ++n_idx) {
#pragma unroll
for (int idx = 0; idx < 4; ++idx) {
C_frag[m_idx][n_idx][idx] += temp_frag[m_idx][n_idx][idx];
}
}
}
}
// first splitk - 1 blocks need to write partial results into C_tmp
if (blockIdx.z != gridDim.z - 1) {
#pragma unroll
for (int m_idx = 0; m_idx < Mtile / 16; ++m_idx) {
#pragma unroll
for (int n_idx = 0; n_idx < WARP_NITER; ++n_idx) {
int offset =
C_tmp_base_offset + (m_idx * WARP_NITER + n_idx) * BLOCK * 4;
asm volatile(
"{st.global.cg.v4.b32 [%0], {%1, %2, %3, %4};}\n"
:
: "l"(params.C_tmp_ptr + offset), "f"(C_frag[m_idx][n_idx][0]),
"f"(C_frag[m_idx][n_idx][1]), "f"(C_frag[m_idx][n_idx][2]),
"f"(C_frag[m_idx][n_idx][3]));
}
}
__threadfence();
__syncthreads();
if (threadIdx.x == 0) {
uint32_t* red_count_ptr = params.red_count_ptr + blk_red_idx;
atomicInc(red_count_ptr, gridDim.z);
}
}
}
}
__device__ void stg(char* smem) {
if (EnableFuse) {
if (blockIdx.z != gridDim.z - 1) return;
}
uint32_t* C_sts_ptr =
reinterpret_cast<uint32_t*>(smem + sts_c_base_offset * sizeof(FType));
// C_tile sts
#pragma unroll
for (int m_idx = 0; m_idx < Mtile / 16; ++m_idx) {
#pragma unroll
for (int n_idx = 0; n_idx < WARP_NITER; ++n_idx) {
#pragma unroll
for (int k_idx = 0; k_idx < 2; ++k_idx) {
FType low16 =
ScalarType<FType>::float2num(C_frag[m_idx][n_idx][k_idx * 2]);
FType high16 =
ScalarType<FType>::float2num(C_frag[m_idx][n_idx][k_idx * 2 + 1]);
uint32_t tmp = (reinterpret_cast<uint32_t&>(low16) & 0xffff) |
(reinterpret_cast<uint32_t&>(high16) << 16);
int sts_offset =
m_idx * 16 * (WARP_NTILE / 2) +
(((lane_id / (32 / WARP_NITER)) + n_idx) % WARP_NITER) * (8 / 2) +
k_idx * 8 * (WARP_NTILE / 2);
C_sts_ptr[sts_offset] = tmp;
}
}
}
__syncthreads();
FType* C_base_ptr = this_block_C_base_ptr + store_c_base_offset;
// C_tile lds and stg
auto m_base_idx = store_c_row_base_idx + blockIdx.x * Mtile;
bool n_guard = (store_c_col_idx + blockIdx.y * Ntile) < params.N;
if (WARP_NTILE == 32) {
int lds_c_base_offset = warp_id * Mtile * WARP_NTILE +
(lane_id / 4) * WARP_NTILE +
((lane_id % 4 + lane_id / 8) % 4) * 8;
uint4* C_lds_ptr =
reinterpret_cast<uint4*>(smem + lds_c_base_offset * sizeof(FType));
#pragma unroll
for (int i = 0; i < (Mtile / 16) * (WARP_NITER / 2); ++i) {
uint4 stg_reg = C_lds_ptr[i * 8 * 4];
stg128(stg_reg.x, stg_reg.y, stg_reg.z, stg_reg.w,
C_base_ptr + i * 8 * params.N,
(m_base_idx + i * 8) < params.M && n_guard);
}
} else if (WARP_NTILE == 64) {
int lds_c_base_offset =
warp_id * Mtile * WARP_NTILE + (lane_id / 8) * WARP_NTILE;
#pragma unroll
for (int i = 0; i < (Mtile / 16) * (WARP_NITER / 2); ++i) {
int lds_c_offset = lds_c_base_offset + i * 4 * WARP_NTILE +
((lane_id % 8 + lane_id / 8 + (i % 2) * 4) % 8) * 8;
uint4 stg_reg =
*reinterpret_cast<uint4*>(smem + lds_c_offset * sizeof(FType));
stg128(stg_reg.x, stg_reg.y, stg_reg.z, stg_reg.w,
C_base_ptr + i * 4 * params.N,
(m_base_idx + i * 4) < params.M && n_guard);
}
}
}
const SM8x_GEMM_W8A16_Splitk_Params<FType, QType>& params;
int load_a_base_offset[2];
int load_b_base_offset[2];
int sts_c_base_offset;
int store_c_base_offset;
int store_c_row_base_idx, store_c_col_idx;
FType* this_block_C_base_ptr = nullptr;
int params_n_idx;
const uint32_t A_smem_base_addr, BQ_smem_base_addr;
const uint32_t A_smem_stage_stride, BQ_smem_stage_stride;
int lane_id;
int warp_id;
// first 2 denotes double buffer, second dim denotes M direction
uint32_t A_frag[2][Mtile / 16][4];
typename HalfType<FType>::T2 B_scale[WARP_NITER / 2];
typename HalfType<FType>::T2 B_zero[WARP_NITER / 2];
uint32_t BQ_frag[2][WARP_NITER];
// first 2 denotes double buffer, second dim denotes N direction, last 2
// denotes K direction
typename HalfType<FType>::T2 BF_frag[2][WARP_NITER][2];
// first dim denotes M direction, second dim denotes N direction
float C_frag[Mtile / 16][WARP_NITER][4];
};
/*
* @brief W8A16 Perchannel Quantization GEMM,
* requires N % 8 == 0, K % 16 == 0
* accumulator precision: FP32
* @tparam FType: DataType for A, B_scale, B_zero, and C, supports half or
* nv_bfloat16
* @tparam QType: DataType for B, support uint8(bias128)
* @tparam Mtile: M-dimensional size of the gemm block tile, supports 16, 32,
* 48 or 64
* @tparam Ntile: N-dimensional size of the gemm block tile, supports 128 or
* 256
* @tparam NStage: Num of stages for async copy
* @tparam BLOCK: BLOCK size
* @tparam EnableFuse: If true, use fused splitk-reduce, otherwise use
* non-fused splitk-reduce
* @tparam has_zp: whether to use zero_point
*
* @fparam params struct consists of following parameters:
* @param A_ptr: Matrix A value ptr, A = (M, K)
* @param B_ptr: Matrix B value ptr, B = (N32_align, K) (N32K16 special
* format), N32_align = (N + 32 - 1) / 32 * 32
* @param B_scale_ptr: B_scale value ptr, B_scale = (N32_align,) (N32K16
* special format)
* @param B_zero_ptr: B_zero value ptr, B_zero = (N32_align,) (N32K16
* special format)
* @param C_ptr: Matrix C value ptr, C = (M, N)
* @param M: dimnesion m
* @param N: dimnesion n
* @param K: dimnesion k
* @param SplitK: split size along K-dimension
* @param C_split_ptr: Matrix C_split value ptr, used only in non-fused
* splitk-reduce
* @param C_tmp_ptr: Matrix C_tmp value ptr, used only in fused
* splitk-reduce
* @param red_count_ptr: 1-D red_count value ptr, used only in fused
* splitk-reduce
*/
template <typename FType, typename QType, int Mtile, int Ntile, int NStage,
int BLOCK, bool EnableFuse, bool has_zp>
__global__ void __launch_bounds__(BLOCK)
ampere_hgemm_W8A16_perc_f16_f16_MtilexNtilex32_hmma16816_multistage_AN_BTN32K16_CN_splitk_kernel(
const SM8x_GEMM_W8A16_Splitk_Params<FType, QType> params) {
// A smem size = 64 * 32 * 2B/elem * 4(stage) = 16KB
// B smem size = 128 * 32 * 1B/elem * 4(stage) = 16KB
constexpr int smem_size_one_stage = Mtile * 32 * 2 + Ntile * 32;
__shared__ char smem[NStage * smem_size_one_stage];
char* A_smem = smem;
char* BQ_smem = smem + Mtile * 32 * 2 * NStage;
uint32_t A_smem_addr = smem_u32addr(A_smem);
uint32_t BQ_smem_addr = smem_u32addr(BQ_smem);
uint32_t A_smem_stage_stride = Mtile * 32 * 2;
uint32_t BQ_smem_stage_stride = Ntile * 32;
// initialize the data move process from GM to SMEM for this block
GmemTile_W8A16_PerC_MtilexNtilex32_multistage_SM8x_SplitK<
FType, QType, Mtile, Ntile, NStage, BLOCK>
gmem_tile(params, A_smem_addr, BQ_smem_addr, A_smem_stage_stride,
BQ_smem_stage_stride);
int sts_stage_idx = 0;
int lds_stage_idx = 0;
auto tb_k_slice = blockIdx.z * params.SplitK + params.SplitK <= params.K
? params.SplitK
: params.K - blockIdx.z * params.SplitK;
int k_tiles = (tb_k_slice + 31) / 32;
int first_k_tile = tb_k_slice - (k_tiles - 1) * 32;
// load first three tiles to shared memory
gmem_tile.ldgsts_first_ktiles(first_k_tile, k_tiles);
sts_stage_idx += (NStage - 2);
ComputeTile_W8A16_PerC_MtilexNtilex32_multistage_SM8x_SplitK<
FType, QType, Mtile, Ntile, BLOCK, EnableFuse, has_zp>
compute_tile(params, A_smem_addr, BQ_smem_addr, A_smem_stage_stride,
BQ_smem_stage_stride);
compute_tile.ldg_params();
cp_asyc_wait_group<NStage - 2>();
__syncthreads();
compute_tile.lds(lds_stage_idx, 0, 0);
int reg_buf_idx = 1;
// main loop
for (; k_tiles > NStage - 1; --k_tiles) {
// load next A&B tile
sts_stage_idx = sts_stage_idx < NStage - 1 ? sts_stage_idx + 1 : 0;
gmem_tile.ldgsts(sts_stage_idx);
#pragma unroll
for (int k_phase_idx = 0; k_phase_idx < 2; k_phase_idx++) {
// dequantize next B tile
if (k_phase_idx == 1) {
cp_asyc_wait_group<NStage - 2>();
__syncthreads();
lds_stage_idx = lds_stage_idx < NStage - 1 ? lds_stage_idx + 1 : 0;
}
compute_tile.lds(lds_stage_idx, reg_buf_idx, (k_phase_idx + 1) % 2);
compute_tile.mma(reg_buf_idx ^ 1);
reg_buf_idx ^= 1;
}
}
// last NStage-1 tiles
for (; k_tiles > 0; --k_tiles) {
cp_async_commit_group();
#pragma unroll
for (int k_phase_idx = 0; k_phase_idx < 2; k_phase_idx++) {
// dequantize next B tile
if (k_phase_idx == 1) {
cp_asyc_wait_group<NStage - 2>();
__syncthreads();
lds_stage_idx = lds_stage_idx < NStage - 1 ? lds_stage_idx + 1 : 0;
}
compute_tile.lds(lds_stage_idx, reg_buf_idx, (k_phase_idx + 1) % 2);
compute_tile.mma(reg_buf_idx ^ 1);
reg_buf_idx ^= 1;
}
}
if (EnableFuse) {
compute_tile.fused_splitk_reduce();
}
compute_tile.stg(smem);
}
#define __CALL_IF(MTILE, NTILE, NUM_THREADS, ENABLE_FUSE, HAS_ZP) \
else if (Mtile == MTILE && Ntile == NTILE && BLOCK == NUM_THREADS && \
enable_fuse == ENABLE_FUSE && has_zp == HAS_ZP) { \
ampere_hgemm_W8A16_perc_f16_f16_MtilexNtilex32_hmma16816_multistage_AN_BTN32K16_CN_splitk_kernel< \
FType, QType, MTILE, NTILE, 4, NUM_THREADS, ENABLE_FUSE, HAS_ZP> \
<<<grid, block, 0, stream>>>(params); \
}
template <typename FType, typename QType>
void ampere_hgemm_W8A16_perc_f16_f16_MtilexNtilex32_mma16816_multistage_AN_BTN32K16_CN_splitk(
const FType* A, const QType* B, const FType* B_scale, const FType* B_zero,
FType* C, const int M, const int N, const int K, void* workspace,
const int sm_version, const BlockTileSplitkParams& fused_gemm_params,
cudaStream_t stream) {
int Mtile = fused_gemm_params.Mtile;
int grid_x = (M + Mtile - 1) / Mtile;
int Ntile = fused_gemm_params.Ntile;
int grid_y = (N + Ntile - 1) / Ntile;
int SplitK = fused_gemm_params.SplitK;
int grid_z = (K + SplitK - 1) / SplitK;
int BLOCK = (Ntile == 256) ? 256 : 128;
dim3 grid(grid_x, grid_y, grid_z);
dim3 block(BLOCK);
bool enable_fuse = fused_gemm_params.EnableFuse;
bool has_zp = B_zero != nullptr;
if (enable_fuse) {
float* C_tmp = reinterpret_cast<float*>(workspace);
uint32_t* red_count = reinterpret_cast<uint32_t*>(
(char*)workspace + grid_x * Mtile * grid_y * Ntile * sizeof(float));
CHECK_CUDA(cudaMemsetAsync(red_count, 0, grid_x * grid_y * sizeof(uint32_t),
stream));
SM8x_GEMM_W8A16_Splitk_Params<FType, QType> params{
A, B, B_scale, B_zero, C, M, N,
K, SplitK, 0, -1, nullptr, C_tmp, red_count};
if (false) {
}
// Select the template parameters for kernel launch
// according to the above settings. Tuning is not supported.
__CALL_IF(16, 256, 256, true, false)
__CALL_IF(32, 256, 256, true, false)
__CALL_IF(48, 256, 256, true, false)
__CALL_IF(64, 128, 128, true, false)
__CALL_IF(64, 256, 256, true, false)
__CALL_IF(16, 256, 256, true, true)
__CALL_IF(32, 256, 256, true, true)
__CALL_IF(48, 256, 256, true, true)
__CALL_IF(64, 128, 128, true, true)
__CALL_IF(64, 256, 256, true, true)
} else {
FType* C_split = reinterpret_cast<FType*>(workspace);
SM8x_GEMM_W8A16_Splitk_Params<FType, QType> params{
A, B, B_scale, B_zero, C, M, N,
K, SplitK, 0, -1, C_split, nullptr, nullptr};
if (false) {
}
// Select the template parameters for kernel launch
// according to the above settings. Tuning is not supported.
__CALL_IF(16, 256, 256, false, false)
__CALL_IF(32, 256, 256, false, false)
__CALL_IF(48, 256, 256, false, false)
__CALL_IF(64, 128, 128, false, false)
__CALL_IF(64, 256, 256, false, false)
__CALL_IF(16, 256, 256, false, true)
__CALL_IF(32, 256, 256, false, true)
__CALL_IF(48, 256, 256, false, true)
__CALL_IF(64, 128, 128, false, true)
__CALL_IF(64, 256, 256, false, true)
// SplitK reduce
f16_gemm_splitk_reduce(C_split, C, M, N, grid_z, stream);
}
}
size_t allspark_qgemm_w8a16_perc_n32k16_ampere_workspace_size(
int m, int n, int k, int sm_count,
BlockTileSplitkParams& fused_gemm_params) {
// Determine the block tile and splitk strategy
int m16_times = (m + 16 - 1) / 16;
int Mtile = m16_times <= 4 ? m16_times * 16 : 64;
int grid_x = (m + Mtile - 1) / Mtile;
int Ntile =
(float(grid_x * ((n + 127) / 128)) / sm_count > 10) || (Mtile < 64) ? 256
: 128;
int grid_y = (n + Ntile - 1) / Ntile;
int grid_z;
// split-k
const float SPLIT_THRESHOLD = 0.8;
int n_slice;
for (n_slice = 1; n_slice < k / 256; ++n_slice) {
int n_block = grid_x * grid_y * n_slice;
if (n_block >= sm_count * SPLIT_THRESHOLD &&
(n_block % sm_count == 0 || n_block % sm_count >= sm_count * 0.5)) {
break;
}
}
int k_slice =
(k / n_slice) % 32 == 0 ? k / n_slice : k / n_slice / 32 * 32 + 32;
grid_z = (k + k_slice - 1) / k_slice;
bool enable_fuse = float(grid_x * grid_y) / sm_count >= 0.5 ? 1 : 0;
size_t ws_size;
if (enable_fuse) {
ws_size = grid_x * Mtile * grid_y * Ntile * sizeof(float) // For C_tmp
+ grid_x * grid_y * sizeof(uint32_t); // For red_count
} else {
ws_size = grid_z * m * n * sizeof(__half);
}
fused_gemm_params.Mtile = Mtile;
fused_gemm_params.Ntile = Ntile;
fused_gemm_params.SplitK = k_slice;
fused_gemm_params.EnableFuse = enable_fuse;
return ws_size;
}
// restore from N32K16 order to original N-major order
// K % 16 == 0, N % 8 == 0
// each block process 64(k) * 32(n) result elements
template <typename FT, typename QT>
__global__ void restore_N32_K16_dequantize_rhs_w8a16_perc_kernel(
const QT* qdata, const FT* scales, const FT* zeros, FT* fdata,
const int N_32align, const int N, const int K) {
__shared__ FT smem[64 * 32];
auto warp_id = threadIdx.x / 32;
auto lane_id = threadIdx.x % 32;
const auto src_row_idx = blockIdx.x * 8 + lane_id / 4;
const int src_col_idx =
blockIdx.y * 64 * 4 + warp_id * 16 * 4 + (lane_id % 4) * 16;
const int src_offset = src_row_idx * K * 4 + src_col_idx;
auto params_nidx = blockIdx.x * 32 + (lane_id / 4) * 4;
QT qval_reg[16];
const QT* pdata = qdata + src_offset;
if (src_col_idx < (K * 4)) {
*(reinterpret_cast<uint4*>(qval_reg)) =
*(reinterpret_cast<const uint4*>(qdata + src_offset));
}
FT scale_reg[4];
*(reinterpret_cast<uint2*>(scale_reg)) =
*(reinterpret_cast<const uint2*>(scales + params_nidx));
FT zero_reg[4];
if (zeros != nullptr) {
*(reinterpret_cast<uint2*>(zero_reg)) =
*(reinterpret_cast<const uint2*>(zeros + params_nidx));
}
FT fval_reg[16];
const int sts_base_offset =
(warp_id * 16 + (lane_id % 4) * 2) * 32 + lane_id / 4;
#pragma unroll
for (int ni = 0; ni < 4; ++ni) {
cvt_8bx4_to_16bx4_bias128(
*reinterpret_cast<uint32_t*>(&qval_reg[ni * 4]),
reinterpret_cast<typename HalfType<FT>::T2*>(&(fval_reg[ni * 4])));
#pragma unroll
for (int ki = 0; ki < 4; ++ki) {
if (zeros != nullptr) {
fval_reg[ni * 4 + ki] = __hsub(fval_reg[ni * 4 + ki], zero_reg[ni]);
}
fval_reg[ni * 4 + ki] = __hmul(fval_reg[ni * 4 + ki], scale_reg[ni]);
int sts_offset = sts_base_offset + ((ki / 2) * 8 + (ki % 2)) * 32 +
((ni + lane_id % 4) % 4) * 8;
smem[sts_offset] = fval_reg[ni * 4 + ki];
}
}
__syncthreads();
const int lds_base_offset =
(threadIdx.x / 4) * 32 + ((threadIdx.x % 4 + threadIdx.x / 8) % 4) * 8;
#pragma unroll
for (int i = 0; i < 2; ++i) {
*reinterpret_cast<uint4*>(fval_reg + i * 8) =
*reinterpret_cast<uint4*>(smem + lds_base_offset + i * 32 * 32);
}
const auto dst_row_base_kidx = blockIdx.y * 64 + threadIdx.x / 4;
const auto dst_col_nidx = blockIdx.x * 32 + (threadIdx.x % 4) * 8;
#pragma unroll
for (int i = 0; i < 2; ++i) {
int dst_row_kidx = dst_row_base_kidx + i * 32;
int dst_offset = dst_row_kidx * N + dst_col_nidx;
if (dst_row_kidx < K && dst_col_nidx < N) {
*reinterpret_cast<uint4*>(fdata + dst_offset) =
*reinterpret_cast<uint4*>(fval_reg + i * 8);
}
}
}
template <typename FT, typename QT>
void restore_N32_K16_dequantize_rhs_w8a16(const QT* qdata, const FT* scales,
const FT* zeros, FT* fdata,
const int N_32align, const int N,
const int K, const int GroupSize,
cudaStream_t stream) {
TORCH_CHECK(N % 8 == 0 && K % 16 == 0 && N_32align % 32 == 0,
"Unsupported shape");
if (GroupSize == -1) {
const int BLOCK = 128;
dim3 grid(N_32align / 32, ((K / 16) + 3) / 4);
restore_N32_K16_dequantize_rhs_w8a16_perc_kernel<FT, QT>
<<<grid, BLOCK, 0, stream>>>(qdata, scales, zeros, fdata, N_32align, N,
K);
}
// TODO: Support SubChannel
else {
TORCH_CHECK(false, "Now only support PerChannel");
}
}
template <typename FT, typename QT>
void w8a16_gemm_dq_cublas(const FT* in, const QT* rhs_qdata_ptr,
const FT* rhs_scales_ptr, const FT* rhs_zeros_ptr,
FT* out, void* workspace, const int M,
const int N_32align, const int N, const int K,
const int group_size, cudaStream_t stream,
cublasHandle_t handle) {
static_assert(
std::is_same<FT, half>::value || std::is_same<FT, nv_bfloat16>::value,
"only float16 and bfloat16 is supported");
// Dequant
FT* rhs_fdata_ptr = static_cast<FT*>(workspace);
restore_N32_K16_dequantize_rhs_w8a16(rhs_qdata_ptr, rhs_scales_ptr,
rhs_zeros_ptr, rhs_fdata_ptr, N_32align,
N, K, group_size, stream);
// cuBLAS GEMM
int lda = K;
int ldb = N;
int ldc = N;
const float alpha = 1.0f;
const float beta = 0.0f;
cudaDataType_t cuda_type;
if (std::is_same<FT, __half>::value) {
cuda_type = CUDA_R_16F;
} else {
cuda_type = CUDA_R_16BF;
}
CHECK_CUBLAS(cublasGemmEx(handle, CUBLAS_OP_N, CUBLAS_OP_N, N, M, K, &alpha,
rhs_fdata_ptr, cuda_type, ldb, in, cuda_type, lda,
&beta, out, cuda_type, ldc, CUDA_R_32F,
CUBLAS_GEMM_DEFAULT_TENSOR_OP));
}
template <typename FType, typename QType>
void allspark_qgemm_w8a16_perc_ampere(
const FType* A, const QType* B, const FType* B_scale, const FType* B_zero,
FType* C, const int M, const int N_32align, const int N, const int K,
void* workspace, const BlockTileSplitkParams& fused_gemm_params,
const int group_size, int CUBLAS_M_THRESHOLD, const int sm_version,
cudaStream_t stream, cublasHandle_t handle) {
if (M > CUBLAS_M_THRESHOLD) {
w8a16_gemm_dq_cublas<FType, QType>(A, B, B_scale, B_zero, C, workspace, M,
N_32align, N, K, group_size, stream,
handle);
} else {
ampere_hgemm_W8A16_perc_f16_f16_MtilexNtilex32_mma16816_multistage_AN_BTN32K16_CN_splitk<
FType, QType>(A, B, B_scale, B_zero, C, M, N, K, workspace, sm_version,
fused_gemm_params, stream);
}
}
} // namespace allspark
torch::Tensor allspark_w8a16_gemm(
torch::Tensor const& a, torch::Tensor const& b_qweight,
torch::Tensor const& b_scales, c10::optional<torch::Tensor> const& b_qzeros,
int64_t n, int64_t group_size, int64_t sm_count, int64_t sm_version,
int64_t CUBLAS_M_THRESHOLD, bool has_zp, bool n32k16_reorder) {
// Verify device and strides
TORCH_CHECK(a.device().is_cuda(), "A is not on GPU");
TORCH_CHECK(a.is_contiguous(), "A is not contiguous");
TORCH_CHECK(b_qweight.device().is_cuda(), "b_qweight is not on GPU");
TORCH_CHECK(b_qweight.is_contiguous(), "b_qweight is not contiguous");
TORCH_CHECK(b_scales.device().is_cuda(), "b_scales is not on GPU");
TORCH_CHECK(b_scales.is_contiguous(), "b_scales is not contiguous");
if (has_zp) {
TORCH_CHECK(b_qzeros.value().device().is_cuda(), "b_qzeros is not on GPU");
TORCH_CHECK(b_qzeros.value().is_contiguous(), "b_qzeros is not contiguous");
}
int m = a.size(0);
int n_32align = (n + 32 - 1) / 32 * 32;
int k = a.size(1);
// Verify shape
TORCH_CHECK(b_qweight.size(0) == n_32align,
"Shape mismatch: b_qweight.size(0) = ", b_qweight.size(0),
", n_32align = ", n_32align);
TORCH_CHECK(b_qweight.size(1) == k,
"Shape mismatch: b_qweight.size(1) = ", b_qweight.size(1),
", k = ", k);
TORCH_CHECK(group_size == -1, "Currently only supports group_size = -1");
const at::cuda::OptionalCUDAGuard device_guard(device_of(a));
const void* a_ptr = reinterpret_cast<const void*>(a.data_ptr());
const uint8_t* b_ptr = reinterpret_cast<const uint8_t*>(b_qweight.data_ptr());
const void* b_scale_ptr = reinterpret_cast<const void*>(b_scales.data_ptr());
const void* b_zero_ptr = nullptr;
if (b_qzeros.has_value()) {
b_zero_ptr = reinterpret_cast<const void*>(b_qzeros.value().data_ptr());
}
auto c_options = torch::TensorOptions().dtype(a.dtype()).device(a.device());
torch::Tensor c = torch::empty({m, n}, c_options);
void* c_ptr = reinterpret_cast<void*>(c.data_ptr());
cudaStream_t stream = at::cuda::getCurrentCUDAStream();
cublasHandle_t handle = at::cuda::getCurrentCUDABlasHandle();
allspark::BlockTileSplitkParams fused_gemm_params;
size_t ws_size = 0;
if (m > CUBLAS_M_THRESHOLD) {
ws_size = k * n * 2; // sizeof(f16)==2
} else {
ws_size = allspark::allspark_qgemm_w8a16_perc_n32k16_ampere_workspace_size(
m, n, k, sm_count, fused_gemm_params);
}
auto ws_options = torch::TensorOptions().dtype(at::kChar).device(a.device());
if (as_g_workspace.numel() <
ws_size) { // ws_options: kChar, so numel() is bytes
as_g_workspace = torch::empty({long(ws_size)}, ws_options);
}
void* ws = reinterpret_cast<void*>(as_g_workspace.data_ptr());
if (a.dtype() == at::ScalarType::Half) {
allspark::allspark_qgemm_w8a16_perc_ampere<__half, uint8_t>(
reinterpret_cast<const __half*>(a_ptr), b_ptr,
reinterpret_cast<const __half*>(b_scale_ptr),
reinterpret_cast<const __half*>(b_zero_ptr),
reinterpret_cast<__half*>(c_ptr), m, n_32align, n, k, ws,
fused_gemm_params, group_size, CUBLAS_M_THRESHOLD, sm_version, stream,
handle);
} else if (a.dtype() == at::ScalarType::BFloat16) {
allspark::allspark_qgemm_w8a16_perc_ampere<__nv_bfloat16, uint8_t>(
reinterpret_cast<const __nv_bfloat16*>(a_ptr), b_ptr,
reinterpret_cast<const __nv_bfloat16*>(b_scale_ptr),
reinterpret_cast<const __nv_bfloat16*>(b_zero_ptr),
reinterpret_cast<__nv_bfloat16*>(c_ptr), m, n_32align, n, k, ws,
fused_gemm_params, group_size, CUBLAS_M_THRESHOLD, sm_version, stream,
handle);
}
return c;
}
#endif
TORCH_LIBRARY_IMPL_EXPAND(TORCH_EXTENSION_NAME, CUDA, m) {
m.impl("allspark_w8a16_gemm", &allspark_w8a16_gemm);
}