pymc-devs / pymc-devs/pytensor

Transform graph to make large constants symbolic inputs

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enhancement jax
Dominant language
Python
Stars
644
Forks
208
Avg merge
2d 14h
Merged PRs (30d)
16

Description

Description

JAX jitting can be insanely slow when there are large constants in the graph. We could add a helper to convert any large constants to symbolic inputs (we already did some constant folding work on our end anyway), so JAX can't get hang up on those.

See related discussion on their side: https://github.com/jax-ml/jax/issues/21300

The idea is to have a pytensor.graph.replace.replace_large_constants_by_inputs that returns the graph with constants replaced by PyTensor input variables and the respective values

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start at the proposed pytensor.graph.replace.replace_large_constants_by_inputs entry point and review the related JAX discussion to understand the large-constant problem. Define completion as returning a graph where large constants become PyTensor input variables together with their corresponding values; the issue does not name a specific test file.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
machine-learning
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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