JuliaArrays / JuliaArrays/StaticArrays.jl

Info request: performance of == vs map(==)

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compile-time-performance
Dominant language
Julia
Stars
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Avg merge
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Merged PRs (30d)
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Description

Wondering if the following performance is expected?

#               _
#   _       _ _(_)_     |  Documentation: https://docs.julialang.org
#  (_)     | (_) (_)    |
#   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
#  | | | | | | |/ _` |  |
#  | | |_| | | | (_| |  |  Version 1.6.1 (2021-04-23)
# _/ |\__'_|_|_|\__'_|  |  Official https://julialang.org/ release
#|__/                   |
#
julia> using StaticArrays

julia> @time SVector(1:100...) == SVector(1:100...)
  0.347808 seconds (749.39 k allocations: 48.644 MiB, 15.53% gc time, 99.78% compilation time)
true

julia> @time map(==, [SVector(1:100...)], [SVector(1:100...)]);
 12.972637 seconds (409.54 k allocations: 24.336 MiB, 100.00% compilation time)

Assuming this is expected, wonder if anyone would be willing to shed light on what's happening with map to cause this?

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  4. Open a pull request that references the issue number.

Research direction

Reproduce the two Julia 1.6.1 REPL timings shown in the issue, comparing direct == with map(==) on the SVector inputs. The issue names no source file or test; completion would require explaining whether the compilation and allocation difference is expected and documenting or resolving a confirmed problem.

Written by the indexing model from the issue text.

Assessment

Tech stack
julia
Domain
performance
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
32/100

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