JuliaLang/julia

Greedy: want atsign-simd working for zip

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#15,378 opened on Mar 6, 2016

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compiler:simdhelp wanted

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Description

Inspired by https://github.com/JuliaLang/julia/pull/15356#issuecomment-192931987 and the discussion there, it would be lovely if the following worked:

@simd for (IA, IB) in zip(eachindex(A), eachindex(B))
    @inbounds s += A[IA] * B[IB]
end

Contributor guide

Research direction
Examine the @simd macro implementation in Julia's base/compiler and understand how it currently handles loop iterations. Investigate how zip iterators are expanded and propose modifications to support SIMD vectorization over zipped loops.
Tech stack
julia
Domain
backendperformance
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.
1-3 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
JuliaSIMD concepts
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
40