ai.onnx.ConstantOfShape
ai.onnx · standard ONNX operator · ONNX opset ≥ 9
Description
Generates a tensor filled with a constant value and an input-specified shape. The shape is provided as a 1-D integer tensor; if empty, the output is a scalar. The fill value and its dtype are taken from the value attribute, defaulting to 0 of type float32.
See the ONNX ConstantOfShape spec for the reference semantics.
Inputs
| Name | Logical dtype | WebGPU storage | Rank | Shape | Description | Presence |
|---|---|---|---|---|---|---|
input |
S |
uint32 |
1 |
— | Logical int64 1-D tensor whose elements define the output shape; all values must be non-negative and use uint32 WebGPU storage. | required |
Outputs
| Name | Logical dtype | Rank | Shape | Description | Presence |
|---|---|---|---|---|---|
output |
T |
derived | — | Output tensor of the shape given by input, filled with the constant value. |
required |
Attributes
Attributes and default values (overridable per request):
| Attribute | Default | Description |
|---|---|---|
value |
— | Optional single-element tensor specifying the fill value and output dtype; defaults to 0 of type float32 if omitted. |
Type constraints
| Variable | Allowed dtypes |
|---|---|
S |
int64 |
T |
float32, float16, int32, int16, uint32, int8, uint8, bool |
Implementation variants
One implementation is selected per call from the device capabilities, the request shapes and the dtypes; these notes say what each one covers.
fill_float_tail— Uses vec4 stores for the aligned prefix and a one-invocation scalar tail when the element count is not divisible by four.fill_integer_tail— Uses vec4 stores for the aligned prefix and a one-invocation scalar tail when the element count is not divisible by four.
Files
metadata.json— kernel metadata (id, digests, per-variant templates, provenance)manifest.json— the op contract (source of truth)test.json— correctness casesbench.json— benchmark + tuning casesconstant-of-shape.wgsl.jinja
Use with @huggingface/kernels
npm install --save-exact @huggingface/kernels@0.0.1-preview.2
Outputs with inferable metadata are allocated automatically. Explicit outputs entries request optional results or provide metadata that cannot be inferred from the supplied inputs and attributes.
This example supplies explicit metadata for:
output
The version: 1 option selects the published kernel contract; it is independent of any operator opset, contrib since_version, or model version.
It follows the v1 branch as fixes land. To pin exact artifact bytes, pass a 40-character commit revision instead of version.
Replace each *Data placeholder with a typed array containing the corresponding input data.
import { getKernel } from "@huggingface/kernels";
const kernel = await getKernel("webgpu-kernels/ai.onnx.ConstantOfShape", { version: 1 });
// Explicit destinations request optional results or supply metadata that cannot be inferred.
const { output } = await kernel({ input: { data: inputData, shape: [2] } }, {
outputs: { output: { shape: [2, 3], dtype: "float32" } },
});
- Downloads last month
- -
Requires WebGPU support. See the compatibility table.