salijagic
61 lines
2.1 KiB
Markdown
61 lines
2.1 KiB
Markdown
# Optimization: SoA (float version)
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- **Author**: Smail
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- **Predecessor**: variant_float_inlining_SoA.cpp
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- **File(s)**: variants/variant_float_inlining_SoA_symmetry.cpp
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- **Status**: TBD
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## What this changes
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Implemented a LUT for calculating the distances since they are symmetric. Saves n_p/2 sqrt
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## Code (relevant snippet)
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See `variants/variant_float_inlining_SoA.cpp`.
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## Benchmark
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Conditions: min of N runs (TBD), N_ITER=1000, -O3 -march=native -flto.
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Diff is vs `variant_float_inlining`.
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### x86
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**Machine**: TBD
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**Frequency**: TBD
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| N | W(n) [Flops] | T(n) [Cycles] | Performance [Flops/Cycle] | Diff vs Predecessor |
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| ---- | ------------ | ------------- | ------------------------- | ------------------- |
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| 50 | | | | |
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| 100 | | | | |
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| 200 | | | | |
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| 500 | | | | |
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### ARM (Apple)
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**Machine**: TBD
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**Frequency**: TBD
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| N | W(n) [Flops] | T(n) [Cycles] | Performance [Flops/Cycle] | Diff vs Predecessor |
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| ---- | ------------ | ------------- | ------------------------- | ------------------- |
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| 50 | | | | |
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| 100 | | | | |
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| 200 | | | | |
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| 500 | | | | |
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## Analysis
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Layout change only, so the expectation is roughly no win on its own. The
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float scalar loop already auto-vectorises in pieces with `-O3
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-march=native`, so SoA doesnt buy much over what the AoS version was
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already doing. The real payoff lands in the AVX2 child.
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Verify passes against `baseline_float_n60_i500.csv` (from
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`variant_float_baseline`) at the 1cm tolerance.
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## Takeaway
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Setup step for the AVX2 variant.
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