[1/2] Add Kernel support for Cutlass based Fused FP4 MoE (#6093)

Signed-off-by: Pavani Majety <pmajety@nvidia.com>
This commit is contained in:
Pavani Majety
2025-06-02 13:48:03 -07:00
committed by GitHub
parent df7f61ee7d
commit eb38c7d1ca
12 changed files with 1677 additions and 22 deletions

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@@ -210,6 +210,7 @@ set(SOURCES
"csrc/gemm/fp8_blockwise_gemm_kernel.cu"
"csrc/gemm/fp8_gemm_kernel.cu"
"csrc/gemm/int8_gemm_kernel.cu"
"csrc/gemm/nvfp4_expert_quant.cu"
"csrc/gemm/nvfp4_quant_entry.cu"
"csrc/gemm/nvfp4_quant_kernels.cu"
"csrc/gemm/nvfp4_scaled_mm_entry.cu"
@@ -222,6 +223,7 @@ set(SOURCES
"csrc/moe/moe_align_kernel.cu"
"csrc/moe/moe_fused_gate.cu"
"csrc/moe/moe_topk_softmax_kernels.cu"
"csrc/moe/nvfp4_blockwise_moe.cu"
"csrc/moe/fp8_blockwise_moe_kernel.cu"
"csrc/moe/prepare_moe_input.cu"
"csrc/moe/ep_moe_reorder_kernel.cu"

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@@ -132,6 +132,20 @@ TORCH_LIBRARY_FRAGMENT(sgl_kernel, m) {
" Tensor! output_scale, Tensor! input_scale) -> ()");
m.impl("scaled_fp4_quant", torch::kCUDA, &scaled_fp4_quant);
// Compute NVFP4 experts quantization.
m.def(
"scaled_fp4_experts_quant(Tensor! output, Tensor! output_scale,"
"Tensor input, Tensor input_global_scale, Tensor input_offset_by_experts,"
"Tensor output_scale_offset_by_experts) -> ()");
m.impl("scaled_fp4_experts_quant", torch::kCUDA, &scaled_fp4_experts_quant);
m.def(
"cutlass_fp4_group_mm(Tensor! output, Tensor a, Tensor b,"
"Tensor a_blockscale, Tensor b_blockscale, Tensor alphas,"
"Tensor ab_strides, Tensor c_strides, Tensor problem_sizes,"
" Tensor expert_offsets, Tensor sf_offsets) -> ()");
m.impl("cutlass_fp4_group_mm", torch::kCUDA, &cutlass_fp4_group_mm);
/*
* From csrc/moe
*/
@@ -161,9 +175,14 @@ TORCH_LIBRARY_FRAGMENT(sgl_kernel, m) {
"expert_offsets, Tensor workspace) -> ()");
m.impl("fp8_blockwise_scaled_grouped_mm", torch::kCUDA, &fp8_blockwise_scaled_grouped_mm);
m.def(
"prepare_moe_input(Tensor topk_ids, Tensor expert_offsets, Tensor problem_sizes1, Tensor problem_sizes2, Tensor "
"input_permutation, Tensor output_permutation, int num_experts, int n, int k) -> ()");
"prepare_moe_input(Tensor topk_ids, Tensor expert_offsets, Tensor? blockscale_offsets, Tensor problem_sizes1,"
" Tensor problem_sizes2, Tensor input_permutation, Tensor output_permutation, int num_experts, int n, int k) -> "
"()");
m.impl("prepare_moe_input", torch::kCUDA, &prepare_moe_input);
m.def("shuffle_rows(Tensor input, Tensor dst2src_map, Tensor output) -> ()");
m.impl("shuffle_rows", torch::kCUDA, &shuffle_rows);
/*
* From csrc/speculative
*/

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@@ -0,0 +1,431 @@
#include <ATen/cuda/CUDAContext.h>
#include <c10/cuda/CUDAGuard.h>
#include <cuda_fp8.h>
#include <cuda_runtime.h>
#include <torch/all.h>
template <typename T>
struct TypeConverter {
using Type = half2;
}; // keep for generality
template <>
struct TypeConverter<half2> {
using Type = half;
};
template <>
struct TypeConverter<half> {
using Type = half2;
};
template <>
struct TypeConverter<__nv_bfloat162> {
using Type = __nv_bfloat16;
};
template <>
struct TypeConverter<__nv_bfloat16> {
using Type = __nv_bfloat162;
};
#define ELTS_PER_THREAD 8
constexpr int CVT_FP4_ELTS_PER_THREAD = 8;
constexpr int CVT_FP4_SF_VEC_SIZE = 16;
// Convert 8 float32 values into 8 e2m1 values (represented as one uint32_t).
inline __device__ uint32_t fp32_vec_to_e2m1(float (&array)[8]) {
// PTX instructions used here requires sm100a.
#if CUDA_VERSION >= 12080
#if defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 1000) && __CUDA_ARCH_HAS_FEATURE__(SM100_ALL)
uint32_t val;
asm volatile(
"{\n"
".reg .b8 byte0;\n"
".reg .b8 byte1;\n"
".reg .b8 byte2;\n"
".reg .b8 byte3;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte0, %2, %1;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte1, %4, %3;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte2, %6, %5;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte3, %8, %7;\n"
"mov.b32 %0, {byte0, byte1, byte2, byte3};\n"
"}"
: "=r"(val)
: "f"(array[0]),
"f"(array[1]),
"f"(array[2]),
"f"(array[3]),
"f"(array[4]),
"f"(array[5]),
"f"(array[6]),
"f"(array[7]));
return val;
#else
return 0;
#endif
#endif
}
// Convert 4 float2 values into 8 e2m1 values (represented as one uint32_t).
inline __device__ uint32_t fp32_vec_to_e2m1(float2 (&array)[4]) {
// PTX instructions used here requires sm100a.
#if CUDA_VERSION >= 12080
#if defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 1000) && __CUDA_ARCH_HAS_FEATURE__(SM100_ALL)
uint32_t val;
asm volatile(
"{\n"
".reg .b8 byte0;\n"
".reg .b8 byte1;\n"
".reg .b8 byte2;\n"
".reg .b8 byte3;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte0, %2, %1;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte1, %4, %3;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte2, %6, %5;\n"
"cvt.rn.satfinite.e2m1x2.f32 byte3, %8, %7;\n"
"mov.b32 %0, {byte0, byte1, byte2, byte3};\n"
"}"
: "=r"(val)
: "f"(array[0].x),
"f"(array[0].y),
"f"(array[1].x),
"f"(array[1].y),
"f"(array[2].x),
"f"(array[2].y),
"f"(array[3].x),
"f"(array[3].y));
return val;
#else
return 0;
#endif
#endif
}
// Fast reciprocal.
inline __device__ float reciprocal_approximate_ftz(float a) {
float b;
asm volatile("rcp.approx.ftz.f32 %0, %1;\n" : "=f"(b) : "f"(a));
return b;
}
template <class SFType, int CVT_FP4_NUM_THREADS_PER_SF>
__device__ uint8_t* cvt_quant_to_fp4_get_sf_out_offset(int rowIdx, int colIdx, int numCols, SFType* SFout) {
#if defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 1000)
static_assert(CVT_FP4_NUM_THREADS_PER_SF == 1 || CVT_FP4_NUM_THREADS_PER_SF == 2);
// One pair of threads write one SF to global memory.
// TODO: stage through smem for packed STG.32
// is it better than STG.8 from 4 threads ?
if (threadIdx.x % CVT_FP4_NUM_THREADS_PER_SF == 0) {
// SF vector index (16 elements share one SF in the K dimension).
int32_t kIdx = colIdx / CVT_FP4_NUM_THREADS_PER_SF;
int32_t mIdx = rowIdx;
// SF layout [numMTiles, numKTiles, 32 (mTile), 4 (mTile), 4(kTile)]
// --> index [mTileIdx, kTileIdx, outerMIdx, innerMIdx, innerKIdx]
int32_t mTileIdx = mIdx / (32 * 4);
// SF vector size 16.
int factor = CVT_FP4_SF_VEC_SIZE * 4;
int32_t numKTiles = (numCols + factor - 1) / factor;
int64_t mTileStride = numKTiles * 32 * 4 * 4;
int32_t kTileIdx = (kIdx / 4);
int64_t kTileStride = 32 * 4 * 4;
// M tile layout [32, 4] is column-major.
int32_t outerMIdx = (mIdx % 32);
int64_t outerMStride = 4 * 4;
int32_t innerMIdx = (mIdx % (32 * 4)) / 32;
int64_t innerMStride = 4;
int32_t innerKIdx = (kIdx % 4);
int64_t innerKStride = 1;
// Compute the global offset.
int64_t SFOffset = mTileIdx * mTileStride + kTileIdx * kTileStride + outerMIdx * outerMStride +
innerMIdx * innerMStride + innerKIdx * innerKStride;
return reinterpret_cast<uint8_t*>(SFout) + SFOffset;
}
#endif
return nullptr;
}
// Define a 16 bytes packed data type.
template <class Type>
struct PackedVec {
typename TypeConverter<Type>::Type elts[4];
};
template <>
struct PackedVec<__nv_fp8_e4m3> {
__nv_fp8x2_e4m3 elts[8];
};
// Quantizes the provided PackedVec into the uint32_t output
template <class Type, bool UE8M0_SF = false>
__device__ uint32_t cvt_warp_fp16_to_fp4(PackedVec<Type>& vec, float SFScaleVal, uint8_t* SFout) {
#if defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 1000)
// Get absolute maximum values among the local 8 values.
auto localMax = __habs2(vec.elts[0]);
// Local maximum value.
#pragma unroll
for (int i = 1; i < CVT_FP4_ELTS_PER_THREAD / 2; i++) {
localMax = __hmax2(localMax, __habs2(vec.elts[i]));
}
// Get the absolute maximum among all 16 values (two threads).
localMax = __hmax2(__shfl_xor_sync(uint32_t(-1), localMax, 1), localMax);
// Get the final absolute maximum values.
float vecMax = float(__hmax(localMax.x, localMax.y));
// Get the SF (max value of the vector / max value of e2m1).
// maximum value of e2m1 = 6.0.
// TODO: use half as compute data type.
float SFValue = SFScaleVal * (vecMax * reciprocal_approximate_ftz(6.0f));
// 8 bits representation of the SF.
uint8_t fp8SFVal;
// Write the SF to global memory (STG.8).
if constexpr (UE8M0_SF) {
// Extract the 8 exponent bits from float32.
// float 32bits = 1 sign bit + 8 exponent bits + 23 mantissa bits.
uint32_t tmp = reinterpret_cast<uint32_t&>(SFValue) >> 23;
fp8SFVal = tmp & 0xff;
// Convert back to fp32.
reinterpret_cast<uint32_t&>(SFValue) = tmp << 23;
} else {
// Here SFValue is always positive, so E4M3 is the same as UE4M3.
__nv_fp8_e4m3 tmp = __nv_fp8_e4m3(SFValue);
reinterpret_cast<__nv_fp8_e4m3&>(fp8SFVal) = tmp;
// Convert back to fp32.
SFValue = float(tmp);
}
// Get the output scale.
// Recipe: final_scale = reciprocal(fp32(fp8(SFValue * SFScaleVal))) *
// reciprocal(SFScaleVal))
float outputScale =
SFValue != 0 ? reciprocal_approximate_ftz(SFValue * reciprocal_approximate_ftz(SFScaleVal)) : 0.0f;
if (SFout) {
// Write the SF to global memory (STG.8).
*SFout = fp8SFVal;
}
// Convert the input to float.
float2 fp2Vals[CVT_FP4_ELTS_PER_THREAD / 2];
#pragma unroll
for (int i = 0; i < CVT_FP4_ELTS_PER_THREAD / 2; i++) {
if constexpr (std::is_same_v<Type, half>) {
fp2Vals[i] = __half22float2(vec.elts[i]);
} else {
fp2Vals[i] = __bfloat1622float2(vec.elts[i]);
}
fp2Vals[i].x *= outputScale;
fp2Vals[i].y *= outputScale;
}
// Convert to e2m1 values.
uint32_t e2m1Vec = fp32_vec_to_e2m1(fp2Vals);
// Write the e2m1 values to global memory.
return e2m1Vec;
#else
return 0;
#endif
}
// Use UE4M3 by default.
template <class Type, bool UE8M0_SF = false>
__global__ void
#if defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 1000)
__launch_bounds__(512, 4) cvt_fp16_to_fp4(
#else
cvt_fp16_to_fp4(
#endif
int32_t numRows,
int32_t numCols,
Type const* in,
float const* SFScale,
uint32_t* out,
uint32_t* SFout,
uint32_t* input_offset_by_experts,
uint32_t* output_scale_offset_by_experts,
int n_experts) {
#if defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 1000)
using PackedVec = PackedVec<Type>;
static constexpr int CVT_FP4_NUM_THREADS_PER_SF = (CVT_FP4_SF_VEC_SIZE / CVT_FP4_ELTS_PER_THREAD);
static_assert(sizeof(PackedVec) == sizeof(Type) * CVT_FP4_ELTS_PER_THREAD, "Vec size is not matched.");
// Input tensor row/col loops.
for (int rowIdx = blockIdx.x; rowIdx < numRows; rowIdx += gridDim.x) {
for (int colIdx = threadIdx.x; colIdx < numCols / CVT_FP4_ELTS_PER_THREAD; colIdx += blockDim.x) {
int64_t inOffset = rowIdx * (numCols / CVT_FP4_ELTS_PER_THREAD) + colIdx;
PackedVec in_vec = reinterpret_cast<PackedVec const*>(in)[inOffset];
// Get the output tensor offset.
// Same as inOffset because 8 elements are packed into one uint32_t.
int64_t outOffset = inOffset;
auto& out_pos = out[outOffset];
// Find index within the experts.
int rowIdx_in_expert = 0;
int expert_idx = 0;
for (int i = 0; i < n_experts; i++) {
if (rowIdx >= input_offset_by_experts[i] && rowIdx < input_offset_by_experts[i + 1]) {
rowIdx_in_expert = rowIdx - input_offset_by_experts[i];
expert_idx = i;
break;
}
}
// Get the global scaling factor, which will be applied to the SF.
// Note SFScale is the same as next GEMM's alpha, which is
// (448.f / (Alpha_A / 6.f)).
float const SFScaleVal = SFScale == nullptr ? 1.0f : SFScale[expert_idx];
int factor = CVT_FP4_SF_VEC_SIZE * 4;
// The actual output_scales dim is computed from the padded numCols.
int32_t numCols_padded = (numCols + factor - 1) / factor * factor;
int numCols_SFout = numCols_padded / CVT_FP4_SF_VEC_SIZE / 4;
uint32_t* SFout_in_expert = SFout + output_scale_offset_by_experts[expert_idx] * numCols_SFout;
auto sf_out = cvt_quant_to_fp4_get_sf_out_offset<uint32_t, CVT_FP4_NUM_THREADS_PER_SF>(
rowIdx_in_expert, colIdx, numCols, SFout_in_expert);
out_pos = cvt_warp_fp16_to_fp4<Type, UE8M0_SF>(in_vec, SFScaleVal, sf_out);
}
}
#endif
}
template <typename T>
void quant_impl(
void* output,
void* output_scale,
void* input,
void* input_global_scale,
void* input_offset_by_experts,
void* output_scale_offset_by_experts,
int m_topk,
int k,
int n_experts,
cudaStream_t stream) {
// TODO: this multiProcessorCount should be cached.
int device;
cudaGetDevice(&device);
int multiProcessorCount;
cudaDeviceGetAttribute(&multiProcessorCount, cudaDevAttrMultiProcessorCount, device);
// Grid, Block size.
// Each thread converts 8 values.
dim3 block(std::min(int(k / ELTS_PER_THREAD), 512));
// Get number of blocks per SM (assume we can fully utilize the SM).
int const numBlocksPerSM = 2048 / block.x;
dim3 grid(std::min(int(m_topk), multiProcessorCount * numBlocksPerSM));
cvt_fp16_to_fp4<T, false><<<grid, block, 0, stream>>>(
m_topk,
k,
reinterpret_cast<T*>(input),
reinterpret_cast<float*>(input_global_scale),
reinterpret_cast<uint32_t*>(output),
reinterpret_cast<uint32_t*>(output_scale),
reinterpret_cast<uint32_t*>(input_offset_by_experts),
reinterpret_cast<uint32_t*>(output_scale_offset_by_experts),
n_experts);
}
/*Quantization entry for fp4 experts quantization*/
#define CHECK_TH_CUDA(x, m) TORCH_CHECK(x.is_cuda(), m, "must be a CUDA tensor")
#define CHECK_CONTIGUOUS(x, m) TORCH_CHECK(x.is_contiguous(), m, "must be contiguous")
#define CHECK_INPUT(x, m) \
CHECK_TH_CUDA(x, m); \
CHECK_CONTIGUOUS(x, m);
// constexpr auto FP8 = at::ScalarType::Float8_e4m3fn;
constexpr auto HALF = at::ScalarType::Half;
constexpr auto BF16 = at::ScalarType::BFloat16;
constexpr auto FLOAT = at::ScalarType::Float;
constexpr auto INT = at::ScalarType::Int;
constexpr auto UINT8 = at::ScalarType::Byte;
void scaled_fp4_experts_quant_sm100a(
torch::Tensor& output,
torch::Tensor& output_scale,
torch::Tensor const& input,
torch::Tensor const& input_global_scale,
torch::Tensor const& input_offset_by_experts,
torch::Tensor const& output_scale_offset_by_experts) {
CHECK_INPUT(output, "output must be a CUDA tensor");
CHECK_INPUT(output_scale, "output_scale must be a CUDA tensor");
CHECK_INPUT(input, "input must be a CUDA tensor");
CHECK_INPUT(input_global_scale, "input_global_scale must be a CUDA tensor");
CHECK_INPUT(input_offset_by_experts, "input_offset_by_experts must be a CUDA tensor");
CHECK_INPUT(output_scale_offset_by_experts, "output_scale_offset_by_experts must be a CUDA tensor");
TORCH_CHECK(output.dim() == 2);
TORCH_CHECK(output_scale.dim() == 2);
TORCH_CHECK(input.dim() == 2);
TORCH_CHECK(input_global_scale.dim() == 1);
TORCH_CHECK(input_offset_by_experts.dim() == 1);
TORCH_CHECK(output_scale_offset_by_experts.dim() == 1);
TORCH_CHECK(input.scalar_type() == HALF || input.scalar_type() == BF16);
TORCH_CHECK(input_global_scale.scalar_type() == FLOAT);
TORCH_CHECK(input_offset_by_experts.scalar_type() == INT);
TORCH_CHECK(output_scale_offset_by_experts.scalar_type() == INT);
// output is uint8 (two nvfp4 values are packed into one uint8)
// output_scale is int32 (four fp8 values are packed into one int32)
TORCH_CHECK(output.scalar_type() == UINT8);
TORCH_CHECK(output_scale.scalar_type() == INT);
const int BLOCK_SIZE = 16;
auto m_topk = input.size(0);
auto k = input.size(1);
TORCH_CHECK(k % BLOCK_SIZE == 0, "k must be a multiple of 16");
auto n_experts = input_global_scale.size(0);
TORCH_CHECK(input_offset_by_experts.size(0) == n_experts + 1);
TORCH_CHECK(output_scale_offset_by_experts.size(0) == n_experts + 1);
TORCH_CHECK(output.size(0) == m_topk);
TORCH_CHECK(output.size(1) == k / 2);
int scales_k = k / BLOCK_SIZE;
// 4 means the swizzle requirement by nvidia nvfp4.
int padded_k = (scales_k + (4 - 1)) / 4 * 4;
// 4 means 4 fp8 values are packed into one int32
TORCH_CHECK(output_scale.size(1) * 4 == padded_k);
auto in_dtype = input.dtype();
at::cuda::CUDAGuard device_guard{(char)input.get_device()};
const cudaStream_t stream = at::cuda::getCurrentCUDAStream(input.get_device());
if (in_dtype == at::ScalarType::Half) {
quant_impl<half>(
output.data_ptr(),
output_scale.data_ptr(),
input.data_ptr(),
input_global_scale.data_ptr(),
input_offset_by_experts.data_ptr(),
output_scale_offset_by_experts.data_ptr(),
m_topk,
k,
n_experts,
stream);
} else if (in_dtype == at::ScalarType::BFloat16) {
quant_impl<__nv_bfloat16>(
output.data_ptr(),
output_scale.data_ptr(),
input.data_ptr(),
input_global_scale.data_ptr(),
input_offset_by_experts.data_ptr(),
output_scale_offset_by_experts.data_ptr(),
m_topk,
k,
n_experts,
stream);
} else {
TORCH_CHECK(false, "Expected input data type to be half or bfloat16");
}
}

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@@ -18,6 +18,15 @@ limitations under the License.
#if defined ENABLE_NVFP4 && ENABLE_NVFP4
void scaled_fp4_quant_sm100a(
torch::Tensor& output, torch::Tensor const& input, torch::Tensor& output_sf, torch::Tensor const& input_sf);
void scaled_fp4_experts_quant_sm100a(
torch::Tensor& output,
torch::Tensor& output_scale,
torch::Tensor const& input,
torch::Tensor const& input_global_scale,
torch::Tensor const& input_offset_by_experts,
torch::Tensor const& output_scale_offset_by_experts);
#endif
void scaled_fp4_quant(
@@ -27,3 +36,17 @@ void scaled_fp4_quant(
#endif
TORCH_CHECK_NOT_IMPLEMENTED(false, "No compiled nvfp4 quantization");
}
void scaled_fp4_experts_quant(
torch::Tensor& output,
torch::Tensor& output_scale,
torch::Tensor const& input,
torch::Tensor const& input_global_scale,
torch::Tensor const& input_offset_by_experts,
torch::Tensor const& output_scale_offset_by_experts) {
#if defined ENABLE_NVFP4 && ENABLE_NVFP4
return scaled_fp4_experts_quant_sm100a(
output, output_scale, input, input_global_scale, input_offset_by_experts, output_scale_offset_by_experts);
#endif
TORCH_CHECK_NOT_IMPLEMENTED(false, "No compiled nvfp4 experts quantization kernel");
}

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@@ -0,0 +1,471 @@
#include <ATen/cuda/CUDAContext.h>
#include <c10/cuda/CUDAGuard.h>
#include <c10/cuda/CUDAStream.h>
#include <cutlass/arch/arch.h>
#include <torch/all.h>
#include <cassert>
#include "cute/tensor.hpp"
#include "cutlass/epilogue/collective/collective_builder.hpp"
#include "cutlass/epilogue/collective/default_epilogue.hpp"
#include "cutlass/epilogue/thread/linear_combination.h"
#include "cutlass/gemm/collective/collective_builder.hpp"
#include "cutlass/gemm/device/gemm_universal_adapter.h"
#include "cutlass/gemm/dispatch_policy.hpp"
#include "cutlass/gemm/group_array_problem_shape.hpp"
#include "cutlass/gemm/kernel/gemm_universal.hpp"
#include "cutlass/tensor_ref.h"
#include "cutlass/util/command_line.h"
#include "cutlass/util/distribution.h"
#include "cutlass/util/host_tensor.h"
#include "cutlass/util/packed_stride.hpp"
#include "cutlass/util/reference/device/gemm.h"
#include "cutlass/util/reference/device/tensor_compare.h"
#include "cutlass/util/reference/host/gett.hpp"
#include "cutlass/util/reference/host/tensor_compare.h"
#include "cutlass/util/reference/host/tensor_fill.h"
#include "cutlass/util/reference/host/tensor_norm.h"
#include "cutlass/util/tensor_view_io.h"
using namespace cute;
template <
typename ElementAB,
typename ElementC,
typename ElementSF,
typename ElementAccumulator,
typename LayoutSFA,
typename LayoutSFB,
typename ScaleConfig>
__global__ void __get_group_gemm_starts(
ElementAB** a_offsets,
ElementAB** b_offsets,
ElementC** out_offsets,
ElementSF** a_scales_offsets,
ElementSF** b_scales_offsets,
ElementAccumulator** alpha_offsets,
LayoutSFA* layout_sfa_base_as_int,
LayoutSFB* layout_sfb_base_as_int,
ElementAB* a_base_as_int,
ElementAB* b_base_as_int,
ElementC* out_base_as_int,
ElementSF* a_scales_base_as_int,
ElementSF* b_scales_base_as_int,
ElementAccumulator* alphas_base_as_int,
const int32_t* expert_offsets,
const int32_t* sf_offsets,
const int32_t* problem_sizes_as_shapes,
const int K,
const int N) {
int64_t expert_id = threadIdx.x;
if (expert_id >= gridDim.x * blockDim.x) {
return;
}
// Originally int32_t but upcasting to int64_t to avoid overflow
// during offset calculations
int64_t expert_offset = static_cast<int64_t>(expert_offsets[expert_id]);
int64_t sf_offset = static_cast<int64_t>(sf_offsets[expert_id]);
// size for block in block scale.
int64_t group_size = 16;
int64_t m = static_cast<int64_t>(problem_sizes_as_shapes[expert_id * 3]);
int64_t n = static_cast<int64_t>(problem_sizes_as_shapes[expert_id * 3 + 1]);
int64_t k = static_cast<int64_t>(problem_sizes_as_shapes[expert_id * 3 + 2]);
assert((m >= 0 && n == N && k == K && k % 2 == 0) && "unexpected problem sizes");
int64_t half_k = static_cast<int64_t>(k / 2);
int64_t group_k = static_cast<int64_t>(k / group_size);
// Shape of A as uint8/byte = [M, K // 2]
// Shape of B as uint8/byte = [E, N, K // 2]
a_offsets[expert_id] = a_base_as_int + expert_offset * half_k;
b_offsets[expert_id] = b_base_as_int + expert_id * n * half_k;
// Shape of C = [M, N]
out_offsets[expert_id] = out_base_as_int + expert_offset * n;
// Shape of a_scale = [sum(sf_sizes), K // group_size]
a_scales_offsets[expert_id] = a_scales_base_as_int + sf_offset * group_k;
assert((reinterpret_cast<uintptr_t>(a_scales_offsets[expert_id]) % 128) == 0 && "TMA requires 128-byte alignment");
// Shape of B scale = [E, N, K // group_size]
b_scales_offsets[expert_id] = b_scales_base_as_int + expert_id * n * group_k;
assert((reinterpret_cast<uintptr_t>(b_scales_offsets[expert_id]) % 128) == 0 && "TMA requires 128-byte alignment");
// Shape of alpha = [E]
alpha_offsets[expert_id] = alphas_base_as_int + expert_id;
LayoutSFA* layout_sfa_ptr = layout_sfa_base_as_int + expert_id;
LayoutSFB* layout_sfb_ptr = layout_sfb_base_as_int + expert_id;
*layout_sfa_ptr = ScaleConfig::tile_atom_to_shape_SFA(
cute::make_shape(static_cast<int>(m), static_cast<int>(n), static_cast<int>(k), 1));
*layout_sfb_ptr = ScaleConfig::tile_atom_to_shape_SFB(
cute::make_shape(static_cast<int>(m), static_cast<int>(n), static_cast<int>(k), 1));
}
#define __CALL_GET_STARTS_KERNEL_BLOCKSCALE( \
ELEMENT_AB_TYPE, SF_TYPE, TENSOR_C_TYPE, C_TYPE, LayoutSFA, LayoutSFB, ScaleConfig) \
else if (out_tensors.dtype() == TENSOR_C_TYPE) { \
__get_group_gemm_starts<ELEMENT_AB_TYPE, C_TYPE, SF_TYPE, float, LayoutSFA, LayoutSFB, ScaleConfig> \
<<<1, num_experts, 0, stream>>>( \
static_cast<ELEMENT_AB_TYPE**>(a_starts.data_ptr()), \
static_cast<ELEMENT_AB_TYPE**>(b_starts.data_ptr()), \
static_cast<C_TYPE**>(out_starts.data_ptr()), \
static_cast<SF_TYPE**>(a_scales_starts.data_ptr()), \
static_cast<SF_TYPE**>(b_scales_starts.data_ptr()), \
static_cast<float**>(alpha_starts.data_ptr()), \
reinterpret_cast<LayoutSFA*>(layout_sfa.data_ptr()), \
reinterpret_cast<LayoutSFB*>(layout_sfb.data_ptr()), \
static_cast<ELEMENT_AB_TYPE*>(a_tensors.data_ptr()), \
static_cast<ELEMENT_AB_TYPE*>(b_tensors.data_ptr()), \
static_cast<C_TYPE*>(out_tensors.data_ptr()), \
static_cast<SF_TYPE*>(a_scales.data_ptr()), \
static_cast<SF_TYPE*>(b_scales.data_ptr()), \
static_cast<float*>(alphas.data_ptr()), \
static_cast<int32_t*>(expert_offsets.data_ptr()), \
static_cast<int32_t*>(sf_offsets.data_ptr()), \
static_cast<int32_t*>(problem_sizes.data_ptr()), \
K, \
N); \
}
template <typename LayoutSFA, typename LayoutSFB, typename ScaleConfig>
void run_get_group_gemm_starts(
const torch::Tensor& a_starts,
const torch::Tensor& b_starts,
const torch::Tensor& out_starts,
const torch::Tensor& a_scales_starts,
const torch::Tensor& b_scales_starts,
const torch::Tensor& alpha_starts,
const torch::Tensor& layout_sfa,
const torch::Tensor& layout_sfb,
/*these are used for their base addresses*/
torch::Tensor const& a_tensors,
torch::Tensor const& b_tensors,
torch::Tensor const& out_tensors,
torch::Tensor const& a_scales,
torch::Tensor const& b_scales,
torch::Tensor const& alphas,
torch::Tensor const& expert_offsets,
torch::Tensor const& sf_offsets,
torch::Tensor const& problem_sizes,
int M,
int N,
int K) {
int num_experts = (int)expert_offsets.size(0);
auto stream = at::cuda::getCurrentCUDAStream(a_tensors.device().index());
TORCH_CHECK(out_tensors.size(1) == N, "Output tensor shape doesn't match expected shape");
TORCH_CHECK(
K / 2 == b_tensors.size(2),
"b_tensors(dim = 2) and a_tensors(dim = 1) trailing"
" dimension must match");
if (false) {
}
//(ELEMENT_AB_TYPE, BS_TYPE, TENSOR_C_TYPE, C_TYPE, LayoutSFA, LayoutSFB,
// ScaleConfig)
__CALL_GET_STARTS_KERNEL_BLOCKSCALE(
cutlass::float_e2m1_t,
cutlass::float_ue4m3_t,
torch::kBFloat16,
cutlass::bfloat16_t,
LayoutSFA,
LayoutSFB,
ScaleConfig)
__CALL_GET_STARTS_KERNEL_BLOCKSCALE(
cutlass::float_e2m1_t, cutlass::float_ue4m3_t, torch::kFloat16, half, LayoutSFA, LayoutSFB, ScaleConfig)
else {
TORCH_CHECK(false, "Invalid output type (must be float16 or bfloat16)");
}
}
template <typename OutType>
void run_fp4_blockwise_scaled_group_mm(
torch::Tensor& output,
const torch::Tensor& a,
const torch::Tensor& b,
const torch::Tensor& a_blockscale,
const torch::Tensor& b_blockscales,
const torch::Tensor& alphas,
const torch::Tensor& ab_strides,
const torch::Tensor& c_strides,
const torch::Tensor& problem_sizes,
const torch::Tensor& expert_offsets,
const torch::Tensor& sf_offsets,
int M,
int N,
int K) {
using ProblemShape = cutlass::gemm::GroupProblemShape<Shape<int32_t, int32_t, int32_t>>;
using ElementType = cutlass::float_e2m1_t;
using ElementSFType = cutlass::float_ue4m3_t;
using ElementA = cutlass::nv_float4_t<cutlass::float_e2m1_t>;
using ElementB = cutlass::nv_float4_t<cutlass::float_e2m1_t>;
using ElementC = OutType;
using ElementD = ElementC;
using ElementAccumulator = float;
// Layout definitions
using LayoutA = cutlass::layout::RowMajor;
using LayoutB = cutlass::layout::ColumnMajor;
using LayoutC = cutlass::layout::RowMajor;
using LayoutD = LayoutC;
// Alignment constraints
static constexpr int AlignmentA = 32;
static constexpr int AlignmentB = 32;
static constexpr int AlignmentC = 128 / cutlass::sizeof_bits<ElementC>::value;
static constexpr int AlignmentD = 128 / cutlass::sizeof_bits<ElementD>::value;
// Architecture definitions
using ArchTag = cutlass::arch::Sm100;
using EpilogueOperatorClass = cutlass::arch::OpClassTensorOp; // Epilogue Operator class tag
using MainloopOperatorClass = cutlass::arch::OpClassBlockScaledTensorOp; // Mainloop Operator class tag
using StageCountType = cutlass::gemm::collective::StageCountAuto; // Stage count maximized based
// on the tile size
using ClusterShape = Shape<_1, _1, _1>;
struct MMA1SMConfig {
using MmaTileShape = Shape<_128, _128, _128>;
using KernelSchedule = cutlass::gemm::KernelPtrArrayTmaWarpSpecialized1SmNvf4Sm100; // Kernel to launch
using EpilogueSchedule = cutlass::epilogue::PtrArrayTmaWarpSpecialized1Sm; // Epilogue to launch
};
using CollectiveEpilogue = typename cutlass::epilogue::collective::CollectiveBuilder<
ArchTag,
EpilogueOperatorClass,
typename MMA1SMConfig::MmaTileShape,
ClusterShape,
Shape<_128, _64>,
ElementAccumulator,
ElementAccumulator,
ElementC,
LayoutC*,
AlignmentC,
ElementD,
LayoutC*,
AlignmentD,
typename MMA1SMConfig::EpilogueSchedule>::CollectiveOp;
using CollectiveMainloop = typename cutlass::gemm::collective::CollectiveBuilder<
ArchTag,
MainloopOperatorClass,
ElementA,
LayoutA*,
AlignmentA,
ElementB,
LayoutB*,
AlignmentB,
ElementAccumulator,
typename MMA1SMConfig::MmaTileShape,
ClusterShape,
cutlass::gemm::collective::StageCountAutoCarveout<static_cast<int>(
sizeof(typename CollectiveEpilogue::SharedStorage))>,
typename MMA1SMConfig::KernelSchedule>::CollectiveOp;
using GemmKernel = cutlass::gemm::kernel::GemmUniversal<ProblemShape, CollectiveMainloop, CollectiveEpilogue>;
using Gemm1SM = cutlass::gemm::device::GemmUniversalAdapter<GemmKernel>;
using Gemm = Gemm1SM;
using StrideA = typename Gemm::GemmKernel::InternalStrideA;
using StrideB = typename Gemm::GemmKernel::InternalStrideB;
using StrideC = typename Gemm::GemmKernel::InternalStrideC;
using StrideD = typename Gemm::GemmKernel::InternalStrideD;
using LayoutSFA = typename Gemm::GemmKernel::CollectiveMainloop::InternalLayoutSFA;
using LayoutSFB = typename Gemm::GemmKernel::CollectiveMainloop::InternalLayoutSFB;
using ScaleConfig = typename Gemm::GemmKernel::CollectiveMainloop::Sm1xxBlkScaledConfig;
using UnderlyingProblemShape = ProblemShape::UnderlyingProblemShape;
int num_experts = static_cast<int>(expert_offsets.size(0));
auto options_int = torch::TensorOptions().dtype(torch::kInt64).device(a.device());
torch::Tensor a_ptrs = torch::empty(num_experts, options_int);
torch::Tensor b_ptrs = torch::empty(num_experts, options_int);
torch::Tensor out_ptrs = torch::empty(num_experts, options_int);
torch::Tensor a_scales_ptrs = torch::empty(num_experts, options_int);
torch::Tensor b_scales_ptrs = torch::empty(num_experts, options_int);
torch::Tensor alpha_ptrs = torch::empty(num_experts, options_int);
torch::Tensor layout_sfa = torch::empty({num_experts, 5}, options_int);
torch::Tensor layout_sfb = torch::empty({num_experts, 5}, options_int);
run_get_group_gemm_starts<LayoutSFA, LayoutSFB, ScaleConfig>(
a_ptrs,
b_ptrs,
out_ptrs,
a_scales_ptrs,
b_scales_ptrs,
alpha_ptrs,
layout_sfa,
layout_sfb,
a,
b,
output,
a_blockscale,
b_blockscales,
alphas,
expert_offsets,
sf_offsets,
problem_sizes,
M,
N,
K);
// Create an instance of the GEMM
Gemm gemm_op;
// Initialize problem_sizes_as_shapes correctly
UnderlyingProblemShape* problem_sizes_as_shapes = static_cast<UnderlyingProblemShape*>(problem_sizes.data_ptr());
// Set the Scheduler info
cutlass::KernelHardwareInfo hw_info;
using RasterOrderOptions = typename cutlass::gemm::kernel::detail::PersistentTileSchedulerSm100GroupParams<
typename ProblemShape::UnderlyingProblemShape>::RasterOrderOptions;
typename Gemm::GemmKernel::TileSchedulerArguments scheduler;
scheduler.raster_order = RasterOrderOptions::AlongM;
hw_info.device_id = a.get_device();
static std::unordered_map<int, int> cached_sm_counts;
if (cached_sm_counts.find(hw_info.device_id) == cached_sm_counts.end()) {
cached_sm_counts[hw_info.device_id] =
cutlass::KernelHardwareInfo::query_device_multiprocessor_count(hw_info.device_id);
}
hw_info.sm_count = min(cached_sm_counts[hw_info.device_id], INT_MAX);
// Mainloop Arguments
typename GemmKernel::MainloopArguments mainloop_args{
static_cast<const ElementType**>(a_ptrs.data_ptr()),
static_cast<StrideA*>(ab_strides.data_ptr()),
static_cast<const ElementType**>(b_ptrs.data_ptr()),
static_cast<StrideB*>(ab_strides.data_ptr()),
static_cast<const ElementSFType**>(a_scales_ptrs.data_ptr()),
reinterpret_cast<LayoutSFA*>(layout_sfa.data_ptr()),
static_cast<const ElementSFType**>(b_scales_ptrs.data_ptr()),
reinterpret_cast<LayoutSFB*>(layout_sfb.data_ptr())};
// Epilogue Arguments
typename GemmKernel::EpilogueArguments epilogue_args{
{}, // epilogue.thread
nullptr,
static_cast<StrideC*>(c_strides.data_ptr()),
static_cast<ElementD**>(out_ptrs.data_ptr()),
static_cast<StrideC*>(c_strides.data_ptr())};
auto& fusion_args = epilogue_args.thread;
fusion_args.alpha_ptr_array = reinterpret_cast<float**>(alpha_ptrs.data_ptr());
fusion_args.dAlpha = {_0{}, _0{}, 1};
// Gemm Arguments
typename GemmKernel::Arguments args{
cutlass::gemm::GemmUniversalMode::kGrouped,
{num_experts, problem_sizes_as_shapes, nullptr},
mainloop_args,
epilogue_args,
hw_info,
scheduler};
size_t workspace_size = Gemm::get_workspace_size(args);
auto const workspace_options = torch::TensorOptions().dtype(torch::kUInt8).device(a.device());
auto workspace = torch::empty(workspace_size, workspace_options);
const cudaStream_t stream = at::cuda::getCurrentCUDAStream(a.get_device());
auto can_implement_status = gemm_op.can_implement(args);
TORCH_CHECK(can_implement_status == cutlass::Status::kSuccess, "Failed to implement GEMM");
// Run the GEMM
auto status = gemm_op.initialize(args, workspace.data_ptr());
TORCH_CHECK(status == cutlass::Status::kSuccess, "Failed to initialize GEMM");
status = gemm_op.run(args, workspace.data_ptr(), stream);
TORCH_CHECK(status == cutlass::Status::kSuccess, "Failed to run GEMM");
}
#define CHECK_TYPE(x, st, m) TORCH_CHECK(x.scalar_type() == st, ": Inconsistency of Tensor type:", m)
#define CHECK_TH_CUDA(x, m) TORCH_CHECK(x.is_cuda(), m, ": must be a CUDA tensor.")
#define CHECK_CONTIGUOUS(x, m) TORCH_CHECK(x.is_contiguous(), m, ": must be contiguous.")
#define CHECK_INPUT(x, st, m) \
CHECK_TH_CUDA(x, m); \
CHECK_CONTIGUOUS(x, m); \
CHECK_TYPE(x, st, m)
void cutlass_fp4_group_mm(
torch::Tensor& output,
const torch::Tensor& a,
const torch::Tensor& b,
const torch::Tensor& a_blockscale,
const torch::Tensor& b_blockscales,
const torch::Tensor& alphas,
const torch::Tensor& ab_strides,
const torch::Tensor& c_strides,
const torch::Tensor& problem_sizes,
const torch::Tensor& expert_offsets,
const torch::Tensor& sf_offsets) {
#if defined ENABLE_NVFP4 && ENABLE_NVFP4
constexpr auto FLOAT4_E2M1X2 = at::ScalarType::Byte;
constexpr auto SF_DTYPE = at::ScalarType::Float8_e4m3fn;
// Input validation
CHECK_INPUT(a, FLOAT4_E2M1X2, "a");
CHECK_INPUT(b, FLOAT4_E2M1X2, "b");
CHECK_INPUT(a_blockscale, SF_DTYPE, "a_blockscale");
CHECK_INPUT(b_blockscales, SF_DTYPE, "b_blockscales");
CHECK_INPUT(alphas, at::ScalarType::Float, "alphas");
TORCH_CHECK(
a_blockscale.dim() == 2,
"expected a_blockscale to be of shape [num_experts, rounded_m,"
" k // group_size], observed rank: ",
a_blockscale.dim())
TORCH_CHECK(
b_blockscales.dim() == 3,
"expected b_blockscale to be of shape: "
" [num_experts, n, k // group_size], observed rank: ",
b_blockscales.dim())
TORCH_CHECK(problem_sizes.dim() == 2, "problem_sizes must be a 2D tensor");
TORCH_CHECK(problem_sizes.size(1) == 3, "problem_sizes must have the shape (num_experts, 3)");
TORCH_CHECK(
problem_sizes.size(0) == expert_offsets.size(0), "Number of experts in problem_sizes must match expert_offsets");
TORCH_CHECK(problem_sizes.dtype() == torch::kInt32, "problem_sizes must be int32.");
int M = static_cast<int>(a.size(0));
int N = static_cast<int>(b.size(1));
int E = static_cast<int>(b.size(0));
int K = static_cast<int>(2 * b.size(2));
if (output.scalar_type() == torch::kBFloat16) {
run_fp4_blockwise_scaled_group_mm<cutlass::bfloat16_t>(
output,
a,
b,
a_blockscale,
b_blockscales,
alphas,
ab_strides,
c_strides,
problem_sizes,
expert_offsets,
sf_offsets,
M,
N,
K);
} else {
run_fp4_blockwise_scaled_group_mm<cutlass::half_t>(
output,
a,
b,
a_blockscale,
b_blockscales,
alphas,
ab_strides,
c_strides,
problem_sizes,
expert_offsets,
sf_offsets,
M,
N,
K);
}
#else
TORCH_CHECK_NOT_IMPLEMENTED(
false,
"No compiled cutlass_fp4_group_mm kernel, sgl-kernel must "
"be compiled with ENABLE_NVFP4 for SM100+ and CUDA "
"12.8 or above.");
#endif
}

View File

@@ -4,6 +4,8 @@
#include <iostream>
#include "cutlass/array.h"
constexpr uint64_t THREADS_PER_EXPERT = 512;
__global__ void compute_problem_sizes(
@@ -11,9 +13,9 @@ __global__ void compute_problem_sizes(
int32_t* problem_sizes1,
int32_t* problem_sizes2,
int32_t* atomic_buffer,
const int topk_length,
const int n,
const int k) {
const int64_t topk_length,
const int64_t n,
const int64_t k) {
int expert_id = blockIdx.x;
int occurrences = 0;
@@ -26,11 +28,11 @@ __global__ void compute_problem_sizes(
if (threadIdx.x == 0) {
int final_occurrences = atomic_buffer[expert_id];
problem_sizes1[expert_id * 3] = final_occurrences;
problem_sizes1[expert_id * 3 + 1] = 2 * n;
problem_sizes1[expert_id * 3 + 2] = k;
problem_sizes1[expert_id * 3 + 1] = static_cast<int32_t>(2 * n);
problem_sizes1[expert_id * 3 + 2] = static_cast<int32_t>(k);
problem_sizes2[expert_id * 3] = final_occurrences;
problem_sizes2[expert_id * 3 + 1] = k;
problem_sizes2[expert_id * 3 + 2] = n;
problem_sizes2[expert_id * 3 + 1] = static_cast<int32_t>(k);
problem_sizes2[expert_id * 3 + 2] = static_cast<int32_t>(n);
}
}
@@ -38,7 +40,7 @@ __global__ void compute_expert_offsets(
const int32_t* __restrict__ problem_sizes1,
int32_t* expert_offsets,
int32_t* atomic_buffer,
const int num_experts) {
const int64_t num_experts) {
int32_t tot_offset = 0;
expert_offsets[0] = 0;
for (int i = 0; i < num_experts; ++i) {
@@ -48,13 +50,34 @@ __global__ void compute_expert_offsets(
}
}
__global__ void compute_expert_blockscale_offsets(
const int32_t* __restrict__ problem_sizes1,
int32_t* expert_offsets,
int32_t* blockscale_offsets,
int32_t* atomic_buffer,
const int64_t num_experts) {
int32_t tot_offset = 0;
int32_t tot_rounded_offset = 0;
expert_offsets[0] = 0;
blockscale_offsets[0] = 0;
for (int i = 0; i < num_experts; ++i) {
atomic_buffer[i] = tot_offset;
int num_tokens = problem_sizes1[i * 3];
int rounded_num_tokens = (num_tokens + (128 - 1)) / 128 * 128;
tot_offset += num_tokens;
tot_rounded_offset += rounded_num_tokens;
expert_offsets[i + 1] = tot_offset;
blockscale_offsets[i + 1] = tot_rounded_offset;
}
}
__global__ void compute_arg_sorts(
const int* __restrict__ topk_ids,
const int32_t* __restrict__ topk_ids,
int32_t* input_permutation,
int32_t* output_permutation,
int32_t* atomic_buffer,
const int topk_length,
const int topk) {
const int64_t topk_length,
const int64_t topk) {
int expert_id = blockIdx.x;
for (int i = threadIdx.x; i < topk_length; i += THREADS_PER_EXPERT) {
@@ -69,6 +92,7 @@ __global__ void compute_arg_sorts(
void get_moe_prepare_input_caller(
const torch::Tensor& topk_ids,
torch::Tensor& expert_offsets,
const std::optional<torch::Tensor>& blockscale_offsets,
torch::Tensor& problem_sizes1,
torch::Tensor& problem_sizes2,
torch::Tensor& input_permutation,
@@ -80,8 +104,10 @@ void get_moe_prepare_input_caller(
auto options_int32 = torch::TensorOptions().dtype(torch::kInt32).device(topk_ids.device());
torch::Tensor atomic_buffer = torch::zeros(num_experts, options_int32);
int num_threads = min(THREADS_PER_EXPERT, topk_ids.numel());
compute_problem_sizes<<<num_experts, num_threads, 0, stream>>>(
uint32_t num_threads = static_cast<uint32_t>(min(THREADS_PER_EXPERT, topk_ids.numel()));
uint32_t num_blocks = static_cast<uint32_t>(num_experts);
compute_problem_sizes<<<num_blocks, num_threads, 0, stream>>>(
static_cast<const int32_t*>(topk_ids.data_ptr()),
static_cast<int32_t*>(problem_sizes1.data_ptr()),
static_cast<int32_t*>(problem_sizes2.data_ptr()),
@@ -89,12 +115,21 @@ void get_moe_prepare_input_caller(
topk_ids.numel(),
n,
k);
compute_expert_offsets<<<1, 1, 0, stream>>>(
static_cast<const int32_t*>(problem_sizes1.data_ptr()),
static_cast<int32_t*>(expert_offsets.data_ptr()),
static_cast<int32_t*>(atomic_buffer.data_ptr()),
num_experts);
compute_arg_sorts<<<num_experts, num_threads, 0, stream>>>(
if (blockscale_offsets.has_value()) {
compute_expert_blockscale_offsets<<<1, 1, 0, stream>>>(
static_cast<const int32_t*>(problem_sizes1.data_ptr()),
static_cast<int32_t*>(expert_offsets.data_ptr()),
static_cast<int32_t*>(blockscale_offsets.value().data_ptr()),
static_cast<int32_t*>(atomic_buffer.data_ptr()),
num_experts);
} else {
compute_expert_offsets<<<1, 1, 0, stream>>>(
static_cast<const int32_t*>(problem_sizes1.data_ptr()),
static_cast<int32_t*>(expert_offsets.data_ptr()),
static_cast<int32_t*>(atomic_buffer.data_ptr()),
num_experts);
}
compute_arg_sorts<<<num_blocks, num_threads, 0, stream>>>(
static_cast<const int32_t*>(topk_ids.data_ptr()),
static_cast<int32_t*>(input_permutation.data_ptr()),
static_cast<int32_t*>(output_permutation.data_ptr()),
@@ -106,6 +141,7 @@ void get_moe_prepare_input_caller(
void prepare_moe_input(
const torch::Tensor& topk_ids,
torch::Tensor& expert_offsets,
const std::optional<torch::Tensor>& blockscale_offsets,
torch::Tensor& problem_sizes1,
torch::Tensor& problem_sizes2,
torch::Tensor& input_permutation,
@@ -117,6 +153,7 @@ void prepare_moe_input(
get_moe_prepare_input_caller(
topk_ids,
expert_offsets,
blockscale_offsets,
problem_sizes1,
problem_sizes2,
input_permutation,
@@ -126,3 +163,92 @@ void prepare_moe_input(
k);
return;
}
template <typename T>
__global__ void shuffleRowsKernel(
const T* input,
const int32_t* dst2src_map,
T* output,
int64_t num_src_rows,
int64_t num_dst_rows,
int64_t num_cols) {
int64_t dest_row_idx = blockIdx.x;
int64_t const source_row_idx = dst2src_map[dest_row_idx];
if (blockIdx.x < num_dst_rows) {
// Load 128-bits per thread
constexpr uint64_t ELEM_PER_THREAD = 128 / sizeof(T) / 8;
using DataElem = cutlass::Array<T, ELEM_PER_THREAD>;
// Duplicate and permute rows
auto const* source_row_ptr = reinterpret_cast<DataElem const*>(input + source_row_idx * num_cols);
auto* dest_row_ptr = reinterpret_cast<DataElem*>(output + dest_row_idx * num_cols);
auto const start_offset = threadIdx.x;
auto const stride = blockDim.x;
auto const num_elems_in_col = num_cols / ELEM_PER_THREAD;
for (auto elem_index = start_offset; elem_index < num_elems_in_col; elem_index += stride) {
dest_row_ptr[elem_index] = source_row_ptr[elem_index];
}
}
}
#define DECLARE_SHUFFLE_ROWS(T) \
__global__ void shuffleRowsKernel( \
const T* input, \
const int32_t* dst2src_map, \
T* output, \
int64_t num_src_rows, \
int64_t num_dest_rows, \
int64_t num_cols);
DECLARE_SHUFFLE_ROWS(float);
DECLARE_SHUFFLE_ROWS(half);
DECLARE_SHUFFLE_ROWS(__nv_bfloat16);
DECLARE_SHUFFLE_ROWS(__nv_fp8_e4m3);
DECLARE_SHUFFLE_ROWS(uint8_t);
#define SHUFFLE_ROWS(T) \
shuffleRowsKernel<T><<<blocks, threads, 0, stream>>>( \
reinterpret_cast<const T*>(input), \
static_cast<const int32_t*>(dst2src_map.data_ptr()), \
reinterpret_cast<T*>(output), \
num_src_rows, \
num_dst_rows, \
num_cols)
#define DTYPE_DISPATCH_CASE(T, CUDA_T) \
case T: \
SHUFFLE_ROWS(CUDA_T); \
break;
void shuffle_rows_caller(
const torch::Tensor& input_tensor, const torch::Tensor& dst2src_map, torch::Tensor& output_tensor) {
TORCH_CHECK(
input_tensor.scalar_type() == output_tensor.scalar_type(),
"Input and output tensors must have the same data type");
auto stream = at::cuda::getCurrentCUDAStream().stream();
uint32_t blocks = static_cast<uint32_t>(output_tensor.size(0));
uint32_t threads = 256;
int64_t num_dst_rows = output_tensor.size(0);
int64_t num_src_rows = input_tensor.size(0);
int64_t num_cols = input_tensor.size(1);
const void* input = input_tensor.data_ptr();
void* output = output_tensor.data_ptr();
switch (input_tensor.scalar_type()) {
DTYPE_DISPATCH_CASE(torch::kFloat16, half);
DTYPE_DISPATCH_CASE(torch::kBFloat16, __nv_bfloat16);
DTYPE_DISPATCH_CASE(torch::kFloat32, float);
DTYPE_DISPATCH_CASE(torch::kFloat8_e4m3fn, __nv_fp8_e4m3);
DTYPE_DISPATCH_CASE(torch::kUInt8, uint8_t);
default:
TORCH_CHECK(false, "[moe replicate input] data type dispatch fail!");
}
return;
}
void shuffle_rows(const torch::Tensor& input_tensor, const torch::Tensor& dst2src_map, torch::Tensor& output_tensor) {
shuffle_rows_caller(input_tensor, dst2src_map, output_tensor);
return;
}

View File

@@ -232,6 +232,7 @@ void fp8_blockwise_scaled_grouped_mm(
void prepare_moe_input(
const torch::Tensor& topk_ids,
torch::Tensor& expert_offsets,
const std::optional<torch::Tensor>& blockscale_offsets,
torch::Tensor& problem_sizes1,
torch::Tensor& problem_sizes2,
torch::Tensor& input_permutation,
@@ -251,6 +252,29 @@ void ep_moe_pre_reorder(
int64_t topk,
bool use_per_token_if_dynamic);
void shuffle_rows(const torch::Tensor& input_tensor, const torch::Tensor& dst2src_map, torch::Tensor& output_tensor);
void cutlass_fp4_group_mm(
torch::Tensor& output,
const torch::Tensor& a,
const torch::Tensor& b,
const torch::Tensor& a_blockscale,
const torch::Tensor& b_blockscales,
const torch::Tensor& alphas,
const torch::Tensor& ab_strides,
const torch::Tensor& c_strides,
const torch::Tensor& problem_sizes,
const torch::Tensor& expert_offsets,
const torch::Tensor& sf_offsets);
void scaled_fp4_experts_quant(
torch::Tensor& output,
torch::Tensor& output_scale,
torch::Tensor const& input,
torch::Tensor const& input_global_scale,
torch::Tensor const& input_offset_by_experts,
torch::Tensor const& output_scale_offset_by_experts);
/*
* From csrc/speculative
*/

View File

@@ -38,14 +38,17 @@ from sgl_kernel.gemm import (
int8_scaled_mm,
qserve_w4a8_per_chn_gemm,
qserve_w4a8_per_group_gemm,
scaled_fp4_experts_quant,
scaled_fp4_quant,
sgl_per_tensor_quant_fp8,
sgl_per_token_group_quant_fp8,
sgl_per_token_group_quant_int8,
sgl_per_token_quant_fp8,
shuffle_rows,
)
from sgl_kernel.grammar import apply_token_bitmask_inplace_cuda
from sgl_kernel.moe import (
cutlass_fp4_group_mm,
ep_moe_pre_reorder,
fp8_blockwise_scaled_grouped_mm,
moe_align_block_size,

View File

@@ -241,3 +241,80 @@ def qserve_w4a8_per_group_gemm(
in_feats, kernel, zeros, scales_i8, wscales, ascales, out_feats
)
return out_feats
def shuffle_rows(input_tensor, dst2src_map, output_tensor_shape):
output_tensor = torch.empty(
output_tensor_shape,
device=input_tensor.device,
dtype=input_tensor.dtype,
)
torch.ops.sgl_kernel.shuffle_rows.default(input_tensor, dst2src_map, output_tensor)
return output_tensor
def scaled_fp4_experts_quant(
input_tensor: torch.Tensor,
input_global_scale: torch.Tensor,
expert_offsets: torch.Tensor,
blockscale_offsets: torch.Tensor,
topk: int,
expert_map: Optional[torch.Tensor] = None,
) -> tuple[torch.Tensor, torch.Tensor]:
"""
Quantize input tensor to FP4 and return quantized tensor and scale, for
packed MoE Inputs.
Args:
input: The input tensor to be quantized to FP4
expert_map: The expert map tensor
input_global_scale: A scalar scaling factor for the entire tensor.
expert_offsets: The expert offsets tensor
blockscale_offsets: The blockscale offsets tensor
Outputs:
output: The quantized tensor in FP4
output_scales: The blockscale tensor in FP8-E4M3
"""
assert (
input_tensor.ndim == 2
), f"input.ndim needs to be == 2, but got {input_tensor.ndim}."
if expert_map is not None:
(m, k) = input_tensor.shape
output_tensor_shape = (m * topk, k)
input_tensor = shuffle_rows(input_tensor, expert_map, output_tensor_shape)
m_numtopk, k = input_tensor.shape
# Control the maximum number of tokens per expert supported by the
# NVFP4 MoE Expert Quantization. This is used to prevent the kernel
# from running out of memory. This value can also be increased to support
# larger models.
import os
MAX_TOKENS_PER_EXPERT = os.environ.get("MODELOPT_MAX_TOKENS_PER_EXPERT", 65536)
assert m_numtopk <= MAX_TOKENS_PER_EXPERT * topk, (
f"m_numtopk must be less than MAX_TOKENS_PER_EXPERT("
f"{MAX_TOKENS_PER_EXPERT})"
f" for cutlass_moe_fp4, observed m_numtopk = {m_numtopk}. Use"
f" MODELOPT_MAX_TOKENS_PER_EXPERT to set this value."
)
scales_k = k // 16
padded_k = (scales_k + (4 - 1)) // 4
# output is uint8 and packed fp4 values
output = torch.empty(
m_numtopk, k // 2, device=input_tensor.device, dtype=torch.uint8
)
output_scales = torch.empty(
MAX_TOKENS_PER_EXPERT * topk,
padded_k,
dtype=torch.int32,
device=input_tensor.device,
)
torch.ops.sgl_kernel.scaled_fp4_experts_quant.default(
output,
output_scales,
input_tensor,
input_global_scale,
expert_offsets,
blockscale_offsets,
)
output_scales = output_scales.view(torch.float8_e4m3fn)
return output, output_scales

View File

@@ -1,3 +1,5 @@
from typing import Optional
import torch
@@ -138,10 +140,12 @@ def prepare_moe_input(
num_experts,
n,
k,
blockscale_offsets: Optional[torch.Tensor] = None,
):
torch.ops.sgl_kernel.prepare_moe_input.default(
topk_ids,
expert_offsets,
blockscale_offsets,
problem_sizes1,
problem_sizes2,
input_permutation,
@@ -150,3 +154,54 @@ def prepare_moe_input(
n,
k,
)
def cutlass_fp4_group_mm(
a_fp4,
b_fp4,
a_blockscale,
b_blockscale,
alphas,
ab_strides,
c_strides,
problem_sizes,
expert_offsets,
blockscale_offsets,
out_dtype,
device,
):
"""
An FP4 Blockscaled Group Gemm that takes in a_tensors, b_tensors and runs
the gemms for each combination based on the specified problem sizes.
This is used as the MoE gemm during NVFP4 Quantized FusedMoE forward.
- a/b_tensors: the NVFP4 a_ptrs and b_ptrs tensors which are quantized
input and expert weights.
- a_/b_scales: The blockscales in FP8-E4M3 precision
- ab_strides/c_strides: Strides for the a/b tensors between rows.
- expert_offsets/sf_offsets: Indices that mark at which token index
each expert begins its computation. The number of tokens
computed with expert E is expert_offsets[E + 1] -
expert_offsets[E] And the sf_size per expert is
sf_offset[E+1] - sf_offset[E]
- problem_sizes: MxNxK sizes of each expert's multiplication in two grouped
MMs used in the fused MoE operation.
"""
m_topk = a_fp4.shape[0]
n = b_fp4.shape[1]
c_shape = (m_topk, n)
c = torch.empty(c_shape, device=device, dtype=out_dtype)
torch.ops.sgl_kernel.cutlass_fp4_group_mm.default(
c,
a_fp4,
b_fp4,
a_blockscale,
b_blockscale,
alphas,
ab_strides,
c_strides,
problem_sizes,
expert_offsets,
blockscale_offsets,
)
return c.to(dtype=out_dtype)