Optimize QR decomposition with SIMD operations in Householder transfo…

[dsyme]

…rmations

• Replace manual scalar dot products with SpanMath.dotUnchecked for SIMD acceleration
• Optimize row updates in updateQ with vectorized operations
• Add zero-check optimization to skip unnecessary work
• Achieve 19-44% speedup across matrix sizes (1.23-1.78× faster)

Performance improvements:

• 10×10: 5.108 μs → 4.140 μs (19.0% faster)
• 30×30: 72.857 μs → 44.644 μs (38.7% faster)
• 50×50: 302.220 μs → 169.798 μs (43.8% faster)

All 1381 tests pass with no change in allocations.

🤖 Generated with Claude Code (https://claude.com/claude-code)

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Transferred from: dsyme/FsMath#1
Original Author: @dsyme

[github-actions]

📊 Code Coverage Report

Summary

Package	Line Rate	Branch Rate	Complexity	Health
FsMath	77%	50%	4415	➖
FsMath	77%	50%	4415	➖
Summary	77% (3104 / 4018)	50% (4326 / 8698)	8830	➖

📈 Coverage Analysis

🟡 Good Coverage Your code coverage is above 60%. Consider adding more tests to reach 80%.

🎯 Coverage Goals

• Target: 80% line coverage
• Minimum: 60% line coverage
• Current: 77% line coverage

📋 What These Numbers Mean

• Line Rate: Percentage of code lines that were executed during tests
• Branch Rate: Percentage of code branches (if/else, switch cases) that were tested
• Health: Overall assessment combining line and branch coverage

🔗 Detailed Reports

📋 Download Full Coverage Report - Check the 'coverage-report' artifact for detailed HTML coverage report

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Coverage report generated on 2025-10-15 at 23:44:38 UTC