[DO NOT MERGE] Coarse/fine setup-repair phases — CI QoR evaluation

[mguthaus]

⚠️ DO NOT MERGE — evaluation-only PR for an experimental coarse→fine repair_timing setup-repair flow. It depends on an out-of-tree OpenROAD branch, so it is not mergeable.

Flow change: sequences setup repair coarse→fine via new COARSE/FINE repair_timing -phases tokens:

• floorplan: COARSE (+ skip last gasp)
• resize (3_4): COARSE FINE (opt-in via ENABLE_PLACE_REPAIR_TIMING)
• post-dpl (new 3_6 target): COARSE FINE
• CTS / global route: COARSE FINE

COARSE = sizeup/clone/buffer/split; FINE = vt_swap/pin-swap/size_down/unbuffer/reroute.

OpenROAD dependency: submodule bumped to VLSIDA/OpenROAD@coarse-fine (9ddd6967fe) — https://github.com/VLSIDA/OpenROAD/tree/coarse-fine — which adds the COARSE/FINE phase tokens and two move-generator crash fixes (RerouteGenerator hierarchical-net; SizeDownFanoutGenerator dangling-path).

Verified locally: gcd/aes/ibex on nangate45 + asap7 complete (rc=0, no crashes).

[gemini-code-assist]

Code Review

This pull request introduces a new post-detailed-placement timing repair step (3_6_place_repair_timing) to the flow, adding a new script repair_timing_post_place.tcl and updating the Makefile. It also enhances repair_timing_helper to support a -phases argument and configures explicit phases across various stages (cts.tcl, floorplan.tcl, global_route.tcl, and resize.tcl). Feedback suggests wrapping the detailed_placement call in repair_timing_post_place.tcl with log_cmd and passing dpl_args for consistency, as well as correcting a comment in the Makefile that inaccurately describes the timing repair phases.

[gemini-code-assist]

The detailed_placement command is called directly without logging via log_cmd and without passing dpl_args (such as -use_negotiation when USE_NEGOTIATION is set). To maintain consistency with other flow scripts and respect user configuration, please define dpl_args and wrap the call in log_cmd.

# Re-legalize after timing repair.
set dpl_args {}
append_env_var dpl_args USE_NEGOTIATION -use_negotiation 0
log_cmd detailed_placement {*}$dpl_args