review follow-up: scalar U64x8 IMM guard; avx512 verification measured, not claimed

[AdaWorldAPI]

What

Addresses the two codex P2 comments on the merged #286 record — both accepted, both verified by measurement:

1. The missing guard was real (src/simd_scalar.rs): scalar U64x8::ternlog lacked the inline const IMM guard that the record marked complete — ternlog::<256> compiled and silently truncated (its U32x16 sibling had the guard; U64x8 did not). Guard added with the identical message every other arm carries; doc paragraph aligned to the every-backend wording with the crate::simd::ternlog pointer.

2. The doctest claim was overstated (.claude/blackboard.md): under the default v3 config the doc examples import the facade types, so the "avx512 examples execute in the doc-test run" sentence described default-facade coverage, not backend verification. Retired via a dated ⊘ correction — and replaced with an actual measurement: this host carries avx512f (cpuinfo), and all five w1a9 facade tests pass under CARGO_BUILD_RUSTFLAGS='-Ctarget-cpu=x86-64-v4' — hardware-executed AVX-512 runtime verification of the backend, recorded as what it is.

Verification

• cargo test --lib -- w1a9 (default v3): 5/5 green
• CARGO_BUILD_RUSTFLAGS='-Ctarget-cpu=x86-64-v4' cargo test --lib w1a9 set: 5/5 green (the new avx512 runtime anchor)
• clippy clean

🤖 Generated with Claude Code

https://claude.ai/code/session_01KCGhDYoQBXs3poaR7sFuqp

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Generated by Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Added compile-time validation to ensure U64x8::ternlog truth-table values are within the supported range.
  • Clarified that validation applies consistently across supported backends.

• Documentation

  • Updated masking primitive documentation to accurately distinguish default coverage from AVX-512 verification.
  • Documented hardware and runtime verification details for AVX-512 support.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: dd61bb62-bd9d-4c78-84c9-8c0a3aca099a

📥 Commits

Reviewing files that changed from the base of the PR and between e03fbd9 and 3378e35.

📒 Files selected for processing (2)

• .claude/blackboard.md
• src/simd_scalar.rs

Included review availability: 1 review is currently available. Your included PR review attempts over the past 7 days set your current allowance at 2 reviews per hour.

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📝 Walkthrough

Walkthrough

The change adds compile-time validation for scalar U64x8::ternlog immediates and updates documentation with accurate backend coverage and x86-64-v4 runtime verification details.

Changes

Ternlog immediate validation

Layer / File(s)	Summary
Scalar ternlog guard and verification src/simd_scalar.rs, .claude/blackboard.md	U64x8::ternlog now rejects immediates outside 0..=255 at compile time. The documentation distinguishes default facade coverage from AVX-512 verification and records x86-64-v4 runtime verification.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: ⚪ Minimal · up to 3378e

The PR adds the missing scalar immediate-value guard and corrects the verification documentation; no actionable merge-blocking risk remains after normal checks and review.

Suggested reviewers: claude

Poem

A rabbit checks the bits in line,

Eight bright lanes now guard the sign.
Out-of-range tables cannot hop,
Compile-time fences make them stop.
AVX paths shine in verified light,
While docs now tell the truth just right.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes both primary changes: adding the scalar U64x8 immediate-value guard and correcting the AVX-512 verification claim.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files. (1 skipped: 1 …
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files. (1 skipped: 1 unsupported.)

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

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