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Optimize AVL tree child bit checking performance (Issue #85) #499

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@konard konard commented Sep 14, 2025 •
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Summary

  • Implements optimal performance solution for AVL tree child existence checking (Issue Determine which solution gives best performance #85)
  • Replaces UncheckedConverter approach with direct bit manipulation
  • Achieves ~4-5x performance improvement (71μs → 17μs average)

Performance Analysis

Comprehensive benchmarking of different approaches:

Approach Mean Time (μs) Performance
Direct Bit Manipulation (Implemented) ~17 🥇 Best
Direct Bit + Unchecked ~18 🥈 2nd
UncheckedConverter (Previous) ~71 3rd
EqualityComparer ~91 4th
EqualityComparer + Unchecked ~99 5th

Implementation

  • Updated GetLeftIsChildValue() and GetRightIsChildValue() in LinksAvlBalancedTreeMethodsBase
  • Uses direct bit operations: ((value >> N) & TLinkAddress.One) != TLinkAddress.Zero
  • Maintains aggressive inlining for maximum performance
  • Preserves all previous approaches in comments for reference

Testing

  • ✅ All existing unit tests pass
  • ✅ Comprehensive benchmarks added to verify performance claims
  • ✅ Backward compatibility maintained

Files Changed

  • LinksAvlBalancedTreeMethodsBase.cs - Core optimization
  • IsChildCheckBenchmarks.cs - Performance verification
  • PERFORMANCE_ANALYSIS.md - Detailed analysis and results

🤖 Generated with Claude Code

Resolves #85

@konard
Initial commit with task details for issue #85
41f434e 
Adding CLAUDE.md with task information for AI processing.
This file will be removed when the task is complete.

Issue: #85
@konard konard self-assigned this Sep 14, 2025
@konard @claude
Optimize AVL tree child bit checking with direct bit manipulation
182348f 
This commit addresses issue #85 by implementing the optimal performance
solution for checking child existence flags in AVL tree nodes.

Performance improvements:
- Replaced UncheckedConverter approach with direct bit manipulation
- Achieved ~4-5x performance improvement (from ~71μs to ~17μs)
- Direct bit operations: ((value >> N) & One) != Zero

Changes:
- Updated GetLeftIsChildValue() and GetRightIsChildValue() methods
- Added comprehensive benchmarks comparing all approaches
- Maintained backward compatibility - all tests pass
- Added detailed performance analysis documentation

The direct bit manipulation approach outperformed:
1. UncheckedConverter (previous): ~71μs → ~17μs
2. EqualityComparer approaches: ~91-98μs
3. Unchecked variants showed minimal benefit

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
@konard konard changed the title [WIP] Determine which solution gives best performance Optimize AVL tree child bit checking performance (Issue #85) Sep 14, 2025
@konard konard marked this pull request as ready for review September 14, 2025 07:12
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Determine which solution gives best performance

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