Files
vllm/csrc/libtorch_stable/torch_bindings.cpp
2026-03-31 10:21:13 -07:00

260 lines
11 KiB
C++

#include "ops.h"
#include "core/registration.h"
#include <torch/csrc/stable/library.h>
// Register ops with STABLE_TORCH_LIBRARY for libtorch stable ABI compatibility.
// Note: We register under namespace "_C" so ops are accessible as
// torch.ops._C.<op_name> for compatibility with existing code.
STABLE_TORCH_LIBRARY_FRAGMENT(_C, ops) {
#ifndef USE_ROCM
ops.def("permute_cols(Tensor A, Tensor perm) -> Tensor");
#endif
#ifndef USE_ROCM
// Compute per-token-group FP8 quantized tensor and scaling factor.
// The dummy arguments are here so we can correctly fuse with RMSNorm.
ops.def(
"per_token_group_fp8_quant(Tensor input, Tensor! output_q, Tensor! "
"output_s, "
"int group_size, float eps, float fp8_min, float fp8_max, bool "
"scale_ue8m0, bool dummy_is_scale_transposed, bool dummy_is_tma_aligned "
") -> ()");
// Compute per-token-group 8-bit quantized tensor and UE8M0-packed,
// TMA-aligned scales for DeepGEMM.
ops.def(
"per_token_group_fp8_quant_packed(Tensor input, Tensor! output_q, "
"Tensor! output_s_packed, int group_size, float eps, float fp8_min, "
"float fp8_max) -> ()");
// Compute per-token-group INT8 quantized tensor and scaling factor.
ops.def(
"per_token_group_quant_int8(Tensor input, Tensor! output_q, Tensor! "
"output_s, int group_size, float eps, float int8_min, float int8_max) -> "
"()");
// CUTLASS w8a8 GEMM, supporting symmetric per-tensor or per-row/column
// quantization, as well as bias
ops.def(
"cutlass_scaled_mm(Tensor! out, Tensor a,"
" Tensor b, Tensor a_scales,"
" Tensor b_scales, Tensor? bias) -> ()");
// CUTLASS w8a8 GEMM, supporting asymmetric per-tensor or per-row/column
// quantization.
ops.def(
"cutlass_scaled_mm_azp(Tensor! out, Tensor a,"
" Tensor b, Tensor a_scales,"
" Tensor b_scales, Tensor azp_adj,"
" Tensor? azp, Tensor? bias) -> ()");
// Check if cutlass scaled_mm is supported for CUDA devices of the given
// capability
ops.def("cutlass_scaled_mm_supports_fp8(int cuda_device_capability) -> bool");
// Check if cutlass grouped gemm is supported for CUDA devices of the given
// capability
ops.def("cutlass_group_gemm_supported(int cuda_device_capability) -> bool");
// CUTLASS w8a8 grouped GEMM
ops.def(
"cutlass_moe_mm(Tensor! out_tensors, Tensor a_tensors, Tensor b_tensors, "
" Tensor a_scales, Tensor b_scales, Tensor expert_offsets, "
" Tensor problem_sizes, Tensor a_strides, "
" Tensor b_strides, Tensor c_strides, bool per_act_token, "
" bool per_out_ch) -> ()");
// A function that computes data required to run fused MoE with w8a8 grouped
// GEMM. It takes topk_ids as an input, and computes expert_offsets
// (token start indices of each expert). In addition to this, it computes
// problem sizes for each expert's multiplication used by the two mms called
// from fused MoE operation, and arrays with permutations required to shuffle
// and de-shuffle the input/output of the fused operation.
ops.def(
"get_cutlass_moe_mm_data(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, Tensor? blockscale_offsets, "
" bool is_gated) -> ()");
// compute per-expert problem sizes from expert_first_token_offset
// produced by vLLM's moe_permute kernel
ops.def(
"get_cutlass_moe_mm_problem_sizes_from_expert_offsets("
" Tensor expert_first_token_offset, "
" Tensor! problem_sizes1, "
" Tensor! problem_sizes2, "
" int n, int k, bool swap_ab) -> ()");
// A function that computes data required to run fused MoE with w8a8 grouped
// GEMM in batched expert format. It takes expert_num_tokens
// as an input, and computes expert_offsets (token start indices of each
// expert). In addition to this, it computes problem sizes for each expert's
// multiplication used by the two mms called from fused MoE operation.
ops.def(
"get_cutlass_batched_moe_mm_data(Tensor! expert_offsets, "
" Tensor! problem_sizes1, "
" Tensor! problem_sizes2, "
" Tensor expert_num_tokens, "
" int num_local_experts, int padded_m, "
" int n, int k) -> ()");
// Check if cutlass scaled_mm supports block quantization (used by DeepSeekV3)
ops.def(
"cutlass_scaled_mm_supports_block_fp8(int cuda_device_capability) -> "
"bool");
// CUTLASS nvfp4 block scaled GEMM
ops.def(
"cutlass_scaled_fp4_mm(Tensor! out, Tensor a, Tensor b,"
" Tensor block_scale_a, Tensor block_scale_b,"
" Tensor alpha) -> ()");
// cutlass nvfp4 block scaled group GEMM
ops.def(
"cutlass_fp4_group_mm(Tensor! out, Tensor a, Tensor b,"
" Tensor a_blockscale, Tensor b_blockscales, Tensor alphas,"
" Tensor problem_sizes, Tensor expert_offsets, Tensor sf_offsets) -> ()");
// Compute NVFP4 block quantized tensor.
ops.def(
"scaled_fp4_quant(Tensor input,"
" Tensor input_scale, bool "
"is_sf_swizzled_layout) -> (Tensor, Tensor)");
// Out variant
// TODO: Add out_variant tag once PyTorch supports it (added in 2.11)
// This registration is now migrated to stable ABI
// at::Tag::out_variant is not available in the stable ABI (enum_tag.h is not
// yet in torch/headeronly), the tag should be applied from Python
// via torch.library.Library.define(..., tags=(torch.Tag.out_variant,))
// with the .impl remaining in C++.
// See pytorch/pytorch#176117.
ops.def(
"scaled_fp4_quant.out(Tensor input,"
" Tensor input_scale, bool "
"is_sf_swizzled_layout, *, Tensor(a!) output, Tensor(b!) output_scale) "
"-> ()");
// Compute NVFP4 experts quantization.
ops.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) -> ()");
// Fused SiLU+Mul+NVFP4 experts quantization.
ops.def(
"silu_and_mul_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) -> ()");
// Fused SiLU+Mul+NVFP4 quantization.
ops.def(
"silu_and_mul_nvfp4_quant(Tensor! result, Tensor! result_block_scale, "
"Tensor input, Tensor input_global_scale) -> ()");
// Check if cutlass_scaled_mm_fp4 is supported for CUDA devices
// of the given capability
ops.def("cutlass_scaled_mm_supports_fp4(int cuda_device_capability) -> bool");
// CUTLASS w4a8 GEMM
ops.def(
"cutlass_w4a8_mm("
" Tensor A,"
" Tensor B,"
" Tensor group_scales,"
" int group_size,"
" Tensor channel_scales,"
" Tensor token_scales,"
" ScalarType? out_type,"
" str? maybe_schedule"
") -> Tensor");
// pack scales
ops.def("cutlass_pack_scale_fp8(Tensor scales) -> Tensor");
// encode and reorder weight matrix
ops.def("cutlass_encode_and_reorder_int4b(Tensor B) -> Tensor");
// CUTLASS w4a8 grouped GEMM
ops.def(
"cutlass_w4a8_moe_mm("
" Tensor! out_tensors,"
" Tensor a_tensors,"
" Tensor b_tensors,"
" Tensor a_scales,"
" Tensor b_scales,"
" Tensor b_group_scales,"
" int b_group_size,"
" Tensor expert_offsets,"
" Tensor problem_sizes,"
" Tensor a_strides,"
" Tensor b_strides,"
" Tensor c_strides,"
" Tensor group_scale_strides,"
" str? maybe_schedule"
") -> ()");
ops.def(
"cutlass_encode_and_reorder_int4b_grouped(Tensor b_tensors) -> (Tensor, "
"Tensor)");
#endif
}
STABLE_TORCH_LIBRARY_IMPL(_C, CUDA, ops) {
#ifndef USE_ROCM
ops.impl("permute_cols", TORCH_BOX(&permute_cols));
#endif
#ifndef USE_ROCM
// Per-token group quantization
ops.impl("per_token_group_fp8_quant", TORCH_BOX(&per_token_group_quant_fp8));
ops.impl("per_token_group_fp8_quant_packed",
TORCH_BOX(&per_token_group_quant_8bit_packed));
ops.impl("per_token_group_quant_int8",
TORCH_BOX(&per_token_group_quant_int8));
// CUTLASS scaled_mm ops
ops.impl("cutlass_scaled_mm", TORCH_BOX(&cutlass_scaled_mm));
ops.impl("cutlass_scaled_mm_azp", TORCH_BOX(&cutlass_scaled_mm_azp));
ops.impl("cutlass_moe_mm", TORCH_BOX(&cutlass_moe_mm));
ops.impl("get_cutlass_moe_mm_data", TORCH_BOX(&get_cutlass_moe_mm_data));
ops.impl("get_cutlass_moe_mm_problem_sizes_from_expert_offsets",
TORCH_BOX(&get_cutlass_moe_mm_problem_sizes_from_expert_offsets));
ops.impl("get_cutlass_batched_moe_mm_data",
TORCH_BOX(&get_cutlass_batched_moe_mm_data));
// FP4/NVFP4 ops
ops.impl("cutlass_scaled_fp4_mm", TORCH_BOX(&cutlass_scaled_fp4_mm));
ops.impl("scaled_fp4_quant", TORCH_BOX(&scaled_fp4_quant_func));
ops.impl("scaled_fp4_quant.out", TORCH_BOX(&scaled_fp4_quant_out));
ops.impl("scaled_fp4_experts_quant", TORCH_BOX(&scaled_fp4_experts_quant));
ops.impl("silu_and_mul_scaled_fp4_experts_quant",
TORCH_BOX(&silu_and_mul_scaled_fp4_experts_quant));
ops.impl("silu_and_mul_nvfp4_quant", TORCH_BOX(&silu_and_mul_nvfp4_quant));
// W4A8 ops: impl registrations are in the source files
// (w4a8_mm_entry.cu and w4a8_grouped_mm_entry.cu)
#endif
}
// These capability-check functions take only primitive args (no tensors), so
// there is no device to dispatch on. CompositeExplicitAutograd makes them
// available for all backends. This is the stable ABI equivalent of calling
// ops.impl("op_name", &func) without a dispatch key in the non-stable API.
STABLE_TORCH_LIBRARY_IMPL(_C, CompositeExplicitAutograd, ops) {
#ifndef USE_ROCM
ops.impl("cutlass_scaled_mm_supports_fp8",
TORCH_BOX(&cutlass_scaled_mm_supports_fp8));
ops.impl("cutlass_group_gemm_supported",
TORCH_BOX(&cutlass_group_gemm_supported));
ops.impl("cutlass_scaled_mm_supports_block_fp8",
TORCH_BOX(&cutlass_scaled_mm_supports_block_fp8));
ops.impl("cutlass_scaled_mm_supports_fp4",
TORCH_BOX(&cutlass_scaled_mm_supports_fp4));
#endif
}
REGISTER_EXTENSION(_C_stable_libtorch)