Use omp simd where feasible
Nobody has claimed this yet.
Assessment
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Newbie friendliness
- 35/100
- Issue type
- Feature
- Clarity
- Needs clarification
- Activity status
- Stale
- Tech stack
- r
- Domain
- performance
Research direction
Start with the discussion in pull request #5441 and identify the inner loops where SIMD may be feasible. Review the relevant implementation and benchmark candidates, ideally on a server CPU with a larger SIMD width. Done means feasible cases are implemented and benchmark results are recorded.
Written by the indexing model from the issue text.
Description
Request came from:
Could hint `#pragma omp simd reduction(max:w)` for the inner loop to the compiler
Originally posted by @ben-schwen in https://github.com/Rdatatable/data.table/pull/5441#discussion_r1443534630
SIMD instructions are more beneficial for a shorter data types, like int32, comparing to float64, which is the case in the linked issue.
For larger types less of the elements will fit into single SIMD instruction.
- identify where simd would be feasible
- implement
- benchmark, ideally using server type CPU that has bigger simd size
- Dominant language
- R
- Stars
- 3.9k
- Forks
- 1.1k
- Avg merge
- 14h 4m
- Merged PRs (30d)
- 4
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
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