taichi-dev/taichi

Invoke materialize() only before calling a Taichi kernel

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#2,730 opened on Aug 19, 2021

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 (5 comments) (0 reactions) (2 assignees)C++ (28,195 stars) (2,384 forks)batch import
good first issuerefactorwelcome contribution

Description

Concisely describe the proposed feature

Originally, materialize() was meant to be invoked immediately before the invocation of a @ti.kernel:

https://github.com/taichi-dev/taichi/blob/9c108ff0e1ce51ba991f1bd4476892d3823fe13a/python/taichi/lang/impl.py#L294-L317

That is, this part is where materialize() is supposed to be called: https://github.com/taichi-dev/taichi/blob/711c299ca9abce4b8a632922ff89295c6939faf3/python/taichi/lang/kernel_impl.py#L383

It is now scattered in several places in the codebase, see

https://github.com/taichi-dev/taichi/search?l=Python&q=%22materialize%28%22

Describe the solution you'd like (if any)

The reasons are two-fold

  1. We used to have to call materialize() before collecting SNode's information. shape has been fixed by @strongoier 's work (#2600) now. However, there are still some places left. We will be happy to guide for the rest of the fix.
  1. There are places where an exception should be thrown if the program is not materialized yet (instead of doing an implicit materialization):

Additional comments Add any other context or screenshots about the feature request here.

Contributor guide

Tech stack
python
Domain
backend
Issue type
refactor
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Familiarity with Taichi's kernel executionUnderstanding of materialize() functionPython knowledge
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
The issue aims to centralize materialize() calls to only before kernel invocation. Currently, materialize() is called in multiple places. The fix involves removing calls in snode.py (lines 295-305) and field.py (lines 201-205) since shape is already handled by PR #2600. Additionally, replace implicit materialization in init .py and aot/module.py (line 79) with exceptions if not materialized. Ensure that materialize() is only called in kernel impl.py line 383. The issue provides specific file links and expects the contributor to understand the codebase.