Equivalence Hooks: Step-by-Step Walkthrough

Step-by-step analysis walkthrough

Use when you own Equivalence Hooks in a synthesis closure review.

1. Confirm exact run context (RTL/SDC/lib/switch set).

2. Open section QoR dashboard and identify first drift.

3. Inspect topic-level report for mechanism evidence.

4. Determine owner and candidate reversible action.

5. Apply one change only; avoid bundled fixes.

6. Run full timing/area/power checks.

7. Validate side effects on neighboring path groups.

8. Publish memo with outcome and residual risk.

Artifacts to collect

• LEC script, mismatch report, waivers log

• QoR dashboard

• run manifest

• constraint diff

• regression matrix

Decision memo template

SYNTHESIS DECISION MEMO — Equivalence Hooks
run context:
observed metric:
hypothesis:
fix:
regression:
owners: formal owner, synthesis owner, CAD owner

Reference visuals

Equivalence hook chain

synthesis/eco transform
      |
      v
mapping points + constraints
      |
      v
LEC proof / mismatch triage

Synthesis deep dive

Incremental and ECO synthesis protect schedule only with strict regression discipline.

Concept diagram

INCREMENTAL ECO LOOP

identify delta -> localized compile -> patch -> regression -> release

Metric graph

ECO CYCLE TIME

full compile      ███████████
incremental       █████

Reports and artifacts

• incremental reuse

• ECO patch list

• LEC status

• regression matrix

Mini case study

Localized compile cut turnaround 40%, but skipped LEC caused rollback.

Debug branches

• Reuse ratio is not enough

• Patch locality check

• Always include equivalence hooks

Senior review question

Ask: what evidence proves this QoR move is real and stable?

Key takeaways

• State exact run context (RTL, SDC, libs, switches) with every QoR claim.

• Re-run timing, area, and power regressions after each synthesis ECO.

Common pitfalls

• Comparing runs with mismatched constraints or library views.

• Timing-only fixes that violate power or area budgets.

• Skipping equivalence checks after structural changes.

Principal synthesis review addendum

Equivalence hooks align synthesis and ECO transformations with formal checking so aggressive optimization remains provably correct.

Metric: LEC pass rate, unresolved points, debug turnaround