CakeML/cakeml

Constant propagation in word_simp

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#1,168 opened on May 5, 2025

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 (6 comments) (0 reactions) (0 assignees)Standard ML (98 forks)auto 404
good first issuelow effort

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Description

At the moment, constant foldng/propagation in wordLang is limited to expressions:

https://github.com/CakeML/cakeml/blob/master/compiler/backend/word_simpScript.sml#L156

This issue is about extending it to work for instructions as well:

https://github.com/CakeML/cakeml/blob/master/compiler/backend/word_simpScript.sml#L220

(and probably other simple places that could benefit).

This was reported by @talsewell in the context of Pancake programs.

Contributor guide

Research direction
Extend constant propagation from expressions to instructions in word simpScript.sml. Follow the pattern in line 156 and apply to line 220.
Tech stack
None
Domain
compilers
Issue type
Feature
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.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Standard MLcompiler backend
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20