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Question about the performance of fused vector operations

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#259 10 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
20/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
haskell
Domain
performance

Research direction

Start with Data.Vector.Unboxed and the Data.Vecor.Fusion.Util Identity (>>=) entry point mentioned in the profile, then review the map/fold usage and storage of intermediate result vectors. Done means establishing whether the reported cost is expected and documenting how those usage patterns affect fused vector performance.

Written by the indexing model from the issue text.

Description

Hi,
I have profiled some of my code that is using Data.Vector.Unboxed and to my confusion the biggest cost centre is the (>>=) on Identity from Data.Vecor.Fusion.Util.
In fact, it is individually responsible for 18% of my execution time. Together with its children it is responsible for 87% of the time, which is expected because my program is basically only using Vectors. I am not familiar with the stream fusion internals of Data.Vector.

Is this performance normal?

One detail about my code: I am mostly using map/fold and I need to store a lot of intermediate result vectors in a datastructure.

Dominant language
Haskell
Stars
401
Forks
145
PR merge metrics
No merged PRs in 30d

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