llvm / llvm/circt

[FIRRTL] Properly handle InstanceChoice in IMCP

Open
#9,701 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

enhancement FIRRTL
Dominant language
C++
Stars
2.2k
Forks
524
Avg merge
3d 2h
Merged PRs (30d)
46

Description

Currently instance results and ports referred from InstanceChoice op are marked overdefined pessimistically.
Technically it's allowed to propagate constant through instance choice as long as lattice states are merged properly.

Contributor guide

No contributing guide indexed for this repository

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 by locating the FIRRTL IMCP handling for InstanceChoice and inspect where instance results and ports are marked overdefined. Done means constant propagation through InstanceChoice works while lattice states are merged correctly instead of being pessimistically overdefined.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.