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Add autograd functions and operator registration for embedding lookup ops#84

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aagalleg wants to merge 39 commits into
intel:mainfrom
aagalleg:feat/lookup_operators_registration
Draft

Add autograd functions and operator registration for embedding lookup ops#84
aagalleg wants to merge 39 commits into
intel:mainfrom
aagalleg:feat/lookup_operators_registration

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@aagalleg

@aagalleg aagalleg commented Jul 3, 2026

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This PR adds the C++ autograd function implementations and PyTorch
operator schema registrations for the dense and split embedding lookup
operators, completing the host-side integration layer between the Python
API and the generated XPU kernels.

Depends on #83

Changes

Autograd Functions (src/codegen/training/ops/)

  • fbgemm_dense_lookups_ops.cpp: Implements the dense embedding
    lookup entry point with full autograd support:

    • SplitNoBagLookupFunctionDenseOpXPU: torch::autograd::Function
      subclass connecting dense_embedding_nobag_forward_unweighted_xpu
      (forward) to split_embedding_nobag_backward_codegen_dense_unweighted_exact_xpu
      (backward) via saved tensors. Includes Kineto trace annotation
      controlled by the TBE_ANNOTATE_KINETO_TRACE feature gate
    • split_embedding_lookup_dense_function_xpu: main dispatch entry
      point registered as fbgemm::dense_embedding_codegen_lookup_function
      under AutogradXPU. Routes to VBE, no-bag, or pooled autograd
      functions based on input parameters — no-bag implemented; VBE and
      pooled return informative TORCH_CHECK errors
  • fbgemm_split_lookups_ops.cpp: Implements the PT2-compatible
    split embedding autograd function with rowwise Adagrad optimizer:

    • SplitNoBagLookupFunction_rowwise_adagrad_Op_pt2:
      torch::autograd::Function subclass using torch::Dispatcher to
      call the registered PT2 wrapper operators for forward and backward
      passes
    • Packs/unpacks aux_tensor, aux_int, aux_float, aux_bool
      parameter arrays using the index constants from pt2_arg_utils.h
    • TBE_V2 feature gate integration for experimental kernel selection
      and Kineto trace annotation support
    • split_embedding_codegen_lookup_rowwise_adagrad_function_pt2_xpu:
      main dispatch entry point registered under AutogradXPU; VBE and
      global weight decay routes guarded with informative errors

Operator Schemas and Python API

  • ops_registry.cpp: Registers all operator schemas under the
    fbgemm namespace via TORCH_LIBRARY_FRAGMENT, guarded with
    schemaExists checks to avoid conflicts with CUDA/CPU registrations.
    New schemas added:

    • dense_embedding_codegen_lookup_function
    • dense_embedding_nobag_forward_unweighted_xpu
    • split_embedding_nobag_backward_codegen_dense_unweighted_exact_xpu
    • split_embedding_codegen_lookup_rowwise_adagrad_function_pt2
    • Forward / backward nobag XPU kernel schemas for split rowwise Adagrad
  • ops.py: Python wrappers for the two new public-facing operators:

    • dense_embedding_codegen_lookup_function()
    • split_embedding_codegen_lookup_rowwise_adagrad_function_pt2()
      Both added to __all__

cc: @flezaalv

aagalleg and others added 30 commits June 18, 2026 22:37
- Add invert_permute kernel to CMake build
- Implement invert_permute Python wrapper in ops.py
- Register invert_permute operator with schema existence check
- Add torch_library.h utility for schema validation
Add SYCL/XPU kernel implementation for invert_permute operation.
Add complete test coverage for invert_permute operator on XPU
devices, covering correctness, validation, parity, and performance.

Test coverage includes:
- Correctness tests for int32/int64 with edge cases (empty, single
  element, identity, reverse, random permutations)
- Input validation tests for invalid dimensions and dtypes
- Meta function tests for torch.compile compatibility
- PyTorch opcheck validation for operator conventions
- Parametric tests with varying sizes (1 to 1M elements)
- CPU-XPU parity tests to ensure consistent results
- Performance benchmarks measuring execution time and bandwidth
- CMakeLists: add permute_1d_sparse_data.cpp to build sources
- ops.py: add Python wrapper with type hints
- ops_registry.cpp: register operator schema in fbgemm namespace
Implement SYCL/XPU kernel implementation of permute_1D_sparse_data
operator for sparse jagged/1D format data permutation.
Add SYCL port of FBGEMM's asynchronous_complete_cumsum operator for
Intel XPU devices. The operator computes a complete cumulative sum
with a leading zero (e.g., [a, b, c] → [0, a, a+b, a+b+c]).
Integrate asynchronous_complete_cumsum operator into fbgemm-xpu:
- Add Python wrapper with complete cumsum documentation
- Register operator schema in torch library
- Include implementation in CMake build
Add comprehensive test suite for asynchronous_complete_cumsum
operator covering:
- Basic functionality with int32 and int64 dtypes
- Empty tensor handling
- Random input validation with numpy reference
Add SYCL infrastructure headers from intel/torch-xpu-ops/
to support advanced kernel implementations:
- DeviceProperties.h: Device capability queries and work group sizing
- SYCLContext.h: SYCL context management and namespace aliases
- SYCLHelpers.h: SYCL kernel submission and utility functions
- TensorInfo.h: Tensor metadata and dimension handling structures
- TensorOptions.h: Tensor configuration and options management
- Runtime.h: SYCL runtime utilities
- Macros.h: Common macro definitions
- Scalar.h: Scalar type conversion utilities

These headers provide the foundation for implementing 2D sparse data
permutation and other complex SYCL operations on XPU devices.
Add foundational utility headers and implementations to support
complex SYCL kernel operations:
- utils.h/cpp: Core constants, type definitions, kernel launch
  helpers, and device property queries
- dispatch_macros.h: Type dispatch macros for handling multiple
  data types (int32, int64, float, etc.)
- tensor_utils.h: Tensor manipulation and metadata utilities
- function_types.h: Symbol visibility definitions for shared
  library exports

These utilities provide essential infrastructure for implementing
2D sparse data permutation and other advanced operators on XPU
devices, including work group sizing, kernel launch helpers, and
type-safe dispatching mechanisms.
Add SYCL port of FBGEMM's permute_2D_sparse_data operator for
Intel XPU devices. This operator permutes 2D sparse data including
lengths [T, B], indices, and optional weights according to a
permutation vector, commonly used for reordering embedding table
features.

Implementation includes:
- SYCL kernels: permute_2D_lengths_kernel and permute_2D_data_kernel
- Host function: permute_2D_sparse_data_xpu
Integrate permute_2D_sparse_data operator into fbgemm-xpu:
- Add Python wrapper with type hints and documentation
- Register operator schema in torch library
- Include implementation files in CMake build (utils.cpp, SYCL
  kernels, and operator implementation)
Add comprehensive test suite for permute_2D_sparse_data operator
covering:
- Basic functionality with int32 and int64 data types
- Sparse data with and without weights
- Permutations with repeated indices
- Exact value validation
- CPU-XPU consistency verification
Fixes CMake configuration and import ordering to properly build and load
the block_bucketize_sparse_features XPU operator.

- Configure CMake for XPU-only PyTorch builds
- Import torch before _C extension to load libtorch.so dependencies
- Adjust test imports for consistency

All 18 tests passing.
… generation

Add jinja_environment.py module to support template-based code
generation for FBGEMM-XPU kernels.
Add common.py module with CodeTemplate class that provides
functionality for loading Jinja2 templates, rendering them with
context variables, and writing generated files with appropriate
headers.
Add torch_type_utils.py module with utilities for handling PyTorch
data types in template-based code generation.
Add generate_forward_split.py and generate_backward_split.py scripts
for generating SYCL embedding kernels from Jinja2 templates.
Add backward_utils.cpp and backward_utils.h with SYCL ports of
FBGEMM backward pass utilities for embedding operations.
…mization

Add vec4.h header implementing 4-element vectorized data structures
for efficient memory access in embedding operations.
Add feature_gates module to enable/disable features at runtime via environment variables.
Add pt2_arg_utils.h header defining argument index enumerations for
PyTorch 2 compiled embedding operations.
Add split_embeddings_cache_xpu.h header defining indices for UVM
(Unified Virtual Memory) cache performance statistics.
…version

Add stochastic_rounding.h header implementing stochastic rounding
algorithms for float-to-half precision conversions in embedding
operations.
Add weight_row.h header implementing abstractions for efficient
access to embedding table weight rows with support for both direct
table access and cache-resident data.
aagalleg added 9 commits July 3, 2026 00:04
Add Jinja2 template for generating optimized SYCL forward kernels
for small embedding dimensions (D <= 32).
Add embedding_forward_split_kernel_template.h as a Jinja2 template
for generating the main SYCL forward kernel for no-bag (sequence)
embeddings.
Add embedding_forward_nobag_unweighted_host_template.cpp as a
Jinja2 template for generating the host-side dispatch function for
no-bag (sequence) embedding forward passes.
…plit

Add embedding_backward_split_kernel_templates.h as a Jinja2 template
for generating SYCL backward kernels for no-bag unweighted embedding
lookups. Generates both dense (gradient-only) and split (rowwise
Adagrad optimizer) variants.
…ghted

Add embedding_backward_nobag_unweighted_host_template.cpp as a
Jinja2 template for generating the host-side backward dispatch
function for no-bag (sequence) embedding passes. Generates both
dense (gradient accumulation) and split (rowwise Adagrad) variants.
…ding

Add embedding_forward_nobag_unweighted_pt2_wrapper_template.cpp as a
Jinja2 template for generating PyTorch 2.0 compilation wrapper
functions for split embedding nobag unweighted operations. The
single template generates both forward and backward wrappers
(controlled by the is_forward flag).
Add fbgemm_dense_lookups_ops.cpp implementing the dense embedding lookup operator for XPU with full autograd support.

NOTE: Since the code in this file and the code in te split operator counterpart are from different templates, the code wasn't fused into a single template.
…ise Adagrad

Add fbgemm_split_lookups_ops.cpp implementing the PT2-compatible autograd function for split embedding lookups with rowwise Adagrad optimizer on XPU.

NOTE: Since the code in this file and the code in the dense operator counterpart are from different templates, the code wasn't fused into a single template.
Register operator schemas and add Python bindings for split and dense
embedding lookup functions. Changes span ops_registry.cpp and ops.py.
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