Fresh 8-seed sweep after DEC-0043's arbiter/mux fix:
- N=4: worst 82.43MHz (was 81.20MHz), mean 89.48MHz (was 91.05MHz) - a wash.
- N=8: worst 77.36MHz (was 80.97MHz), mean 80.71MHz (was 84.62MHz) - a real,
measured regression, though still 8/8 PASS at 64MHz with +21% margin.
P&R is a stochastic heuristic search; removing logic from one path can shift
the placer onto a different, coincidentally worse-mapped critical path for
this specific seed set. Not a functional regression - both configs remain
closed. Keeping the fix regardless: it's bit-exact and removes a known-bad
pattern that gets worse as N_SLOTS grows toward 16, even though it didn't
pay off in Fmax at today's N=8. Full numbers and interpretation in
timing.log.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
micheleandClaude Sonnet 5
e809b71806