Validation and interpretation

All 429 baseline correctness cases passed twice. Every measured fork also checks its selected result before timing. Reference arithmetic and residual checks are outside timing.

All 66 targeted row-swap/row-cycle cases also passed. These check determinant signs, LU permutation orientation and solves on pivoting inputs.

Tables show mean ± JMH 99.9% confidence half-width, in ms/op. These error bars are not standard deviations. Overlapping intervals or high uncertainty make fine rankings unreliable. Chart ratios are ratios of means and do not show ratio uncertainty.

Native input conversion is outside timing; necessary copies, allocations and full factor output materialization are timed. This compares public API tasks, not identical algorithms. NM Dev Inverse detects symmetry and attempts Cholesky on SPD inputs, falling back to LU if that path raises a runtime exception. The exact measured JAR was verified separately by bytecode and runtime constructor-breakpoint tracing; see the fairness audit. F2J transpose/addition/scaling use adapter-owned Java loops because LAPACK does not define those matrix convenience APIs.

Evidence

• JMH JSON and per-fork iteration means
• Complete JMH log
• Summary CSV
• JVM allocation per operation; native allocations are not fully included
• Baseline correctness residuals
• Targeted pivot/sign checks
• Environment and requested thread settings
• Backend records
• Artifact versions and SHA-256 checksums
• Measured source checksums
• Dependency release metadata
• Exact harness source snapshot
• Deferred-output and mutation regression checks

See Methodology for input construction and residual checks.