dotnet/runtime

Remove JIT-workaround for eliminating bound check

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#67,044 opened on Mar 23, 2022

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 (12 comments) (3 reactions) (1 assignee)C# (5,445 forks)batch import
area-CodeGen-coreclrenhancementhelp wanted

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Description

https://github.com/dotnet/runtime/pull/62864 taught the JIT to recognize more pattern to eliminate bound checks for array and span indexing. Thus the workarounds like the uint-casts aren't needed anymore, and could be undone.

Also cf. https://github.com/dotnet/runtime/pull/64899#discussion_r833378404

category:cq theme:bounds-checks skill-level:beginner cost:small impact:small

Contributor guide

Research direction
Identify `(uint)` cast workarounds used for bound check elimination and remove them. Verify that tests pass and bound checks are still eliminated correctly.
Tech stack
csharp
Domain
backend
Issue type
Refactor
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
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.
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.
85