| --- |
| library_name: kernels |
| license: apache-2.0 |
| tags: |
| - kernel |
| - webgpu |
| - wgsl |
| --- |
| # com.microsoft.SkipLayerNormalization |
|
|
| `com.microsoft` · ONNX Runtime contrib operator · contrib since_version 1 |
| |
| ## Description |
| |
| Fuses skip addition with layer normalization. The rank-3 standard surface currently supports float32, required `beta`, no `bias` or residual output, hidden sizes divisible by four, and exact or documented broadcast skip shapes. The provider's rank-2 extension supports float32 output-only with optional `beta`, or `beta` with optional `bias` when emitting the residual; its float16 path requires `beta`, `bias`, a residual output, and four-wide hidden size. Other combinations, bfloat16, and training statistics are not implemented. |
| |
| See the [ONNX Runtime `SkipLayerNormalization` contrib-operator spec](https://github.com/microsoft/onnxruntime/blob/main/docs/ContribOperators.md#com.microsoft.SkipLayerNormalization) for the reference semantics. |
| |
| ## Inputs |
| |
| | Name | Bind key | Logical dtype | Rank | Shape | Description | Presence | |
| | --- | --- | --- | --- | --- | --- | --- | |
| | `input` | `inputT` | `T` | — | — | Primary input normalized over the final hidden-size axis. Rank 3 is the public shape; rank 2 is an ONNX Runtime provider extension supported by this package. | required | |
| | `skip` | `skipT` | `T` | — | — | Residual tensor. For rank-3 input it is exact shape, `(1, sequence_length, hidden_size)`, or `(sequence_length, hidden_size)`; rank-2 input requires exact shape. | required | |
| | `gamma` | `gammaT` | `T` | `1` | — | Layer-norm scale weights of shape `(hidden_size)`. | required | |
| | `beta` | `betaT` | `T` | `1` | — | Layer-norm bias weights of shape `(hidden_size)`. | optional | |
| | `bias` | `biasT` | `T` | `1` | — | Optional additive bias of shape `(hidden_size)` added to `input + skip` before normalization. | optional | |
|
|
| ## Outputs |
|
|
| | Name | Bind key | Logical dtype | Rank | Shape | Description | Presence | |
| | --- | --- | --- | --- | --- | --- | --- | |
| | `output` | `outputT` | `T` | same as `input` | same as `input` | Normalized output tensor with the same shape as `input`. | required | |
| | `input_skip_bias_sum` | `residualT` | `T` | same as `input` | same as `input` | Sum of `input`, `skip`, and `bias` (when present) before normalization, with the same shape as `input`. | optional | |
|
|
| ## Attributes |
|
|
| Default values (overridable per request): |
|
|
| | Attribute | Default | Description | |
| | --- | --- | --- | |
| | `epsilon` | `9.999999960041972e-13` | Non-negative epsilon added to the variance before taking the square root. | |
|
|
| ## Type constraints |
|
|
| | Variable | Allowed dtypes | |
| | --- | --- | |
| | `T` | `float32`, `float16` | |
|
|
| ## Files |
|
|
| - [`metadata.json`](build/webgpu/metadata.json) — kernel metadata (id, digests, provenance) |
| - [`manifest.json`](build/webgpu/manifest.json) — the op contract (source of truth) |
| - [`test.json`](build/webgpu/test.json) — correctness cases |
| - [`bench.json`](build/webgpu/bench.json) — benchmark + tuning cases |
| - [`norm-skip-row-vec4.wgsl.jinja`](build/webgpu/norm-skip-row-vec4.wgsl.jinja) |
| - [`norm-skip-row.wgsl.jinja`](build/webgpu/norm-skip-row.wgsl.jinja) |
|
|
| ## Use with `@huggingface/kernels` |
|
|
| The loader derives every required output's shape and logical dtype from the manifest contract and this call. |
| It then allocates the result tensors automatically. |
|
|
| The `version: 1` option selects the published kernel contract; it is independent of any operator opset, contrib `since_version`, or model version. |
|
|
| Replace each `*Data` placeholder with a typed array containing the corresponding input data. |
|
|
| ```js |
| import { getKernel } from "@huggingface/kernels"; |
| |
| const kernel = await getKernel("webgpu-kernels/com.microsoft.SkipLayerNormalization", { version: 1 }); |
| const { outputT } = await kernel({ |
| inputT: { data: inputTData, shape: [2, 4] }, |
| skipT: { data: skipTData, shape: [2, 4] }, |
| gammaT: { data: gammaTData, shape: [4] }, |
| }); |
| ``` |
|
|
