ai.onnx.If

ai.onnx · internal tensor lowering (non-standard) · reviewed against ONNX opset 25

Description

Support status: the standard ONNX If control-flow operator is not implemented because standalone kernel packages cannot carry or execute its then_branch and else_branch graph attributes. This internal lowering only selects elementwise between two pre-evaluated, equal-sized tensors from a scalar condition and must not be treated as ONNX If.

See the standard ONNX If spec for the contract this internal lowering does not implement.

Inputs

Outputs

Type constraints

Files

• metadata.json — kernel metadata (id, digests, provenance)
• manifest.json — the op contract (source of truth)
• test.json — correctness cases
• bench.json — benchmark + tuning cases
• if-select.wgsl.jinja

Use with @huggingface/kernels

The loader automatically allocates outputs whose metadata it can derive from the manifest contract and this call.

The explicit outputs entries provide shape and logical dtype metadata for the results listed below:

• y

Each entry either requests an optional result or supplies metadata that cannot be inferred from the inputs.

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.

import { getKernel } from "@huggingface/kernels";

const kernel = await getKernel("webgpu-kernels/ai.onnx.If", { version: 1 });
// Explicit destinations request optional results or supply metadata that cannot be inferred.
const { y } = await kernel({
  cond: { data: condData, shape: [1] },
  then_value: { data: then_valueData, shape: [1] },
  else_value: { data: else_valueData, shape: [1] },
}, {
  outputs: { y: { shape: [1], dtype: "float32" } },
});