JuliaLang/julia

Greedy: want atsign-simd working for zip

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#15,378 opened on Mar 6, 2016

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 (1 comment) (0 reactions) (0 assignees)Julia (48,709 stars) (5,773 forks)batch import
compiler:simdhelp wanted

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

Tech stack
None
Domain
backendperformance
Issue type
feature
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.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
Julia macro systemSIMD conceptszip iteration internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
10
Research direction
The issue requests extending @simd to work with zip iterators, inspired by PR #15356. Investigate how @simd currently handles loops and why zip is not supported. Look at the implementation of zip and eachindex in Julia's base library to identify changes needed. Consider revisiting the discussion in #15356 and related issues for context.