missed optimization of and + csel + sub

Repository metrics

Stars

26,378 stars (26,378 stars)

PR merge metrics

Avg merge 1d 2h (Avg merge 1d 2h)1,000 merged PRs in 30d (1,000 merged PRs in 30d)

Description

Contributor guide

Research direction

Examine the alive2 links to understand the missed optimization pattern. Look at the code generation path for `and`, `csel`, and `sub` instructions in the LLVM backend. Identify where the optimization should occur and propose a fix.

Tech stack

cpp

Domain

backend

Issue type

Bug

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

4

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

3-5 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

GitC++

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

20