dotnet/runtime

ARM/ARM64 returns an incorrect result for `pow(x, 1)`

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#12,139 opened on Feb 27, 2019

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 (7 comments) (0 reactions) (0 assignees)C# (5,445 forks)batch import
Priority:3arch-arm32arch-arm64area-System.Numericsbughelp wanted

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Description

ARM/ARM64 currently return 0 for Math.Pow(double.Epsilon, 1) when it should be returning double.Epsilon. My best guess is that the implementation is not properly special casing y=1.

category:correctness theme:jit-intrinsics skill-level:beginner cost:small

Contributor guide

Research direction
Investigate the implementation of Math.Pow in the .NET runtime for ARM/ARM64, specifically the code path that handles the exponent being 1. Look for a special case for y=1 and ensure it returns the base value correctly.
Tech stack
csharp
Domain
backend
Issue type
Bug
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.
80