[minjukim55]

Follow-up to #4706: enable GPL_PLACE_IOS in 11 more public designs, from the designs #4706 had not measured yet.

How it was measured (same as #4706):

• GPL_PLACE_IOS off vs on, same OpenROAD binary, shared synth/floorplan
• global placement seeds 1-10 (-random_seed), run through GRT
• enabled when setup WS improves or stays within the flag-off seed spread, and placement runtime drops; WS differences don't count when both arms meet timing
• also checked fmax, GRT antenna diodes, and that IO_CONSTRAINTS exclude regions still hold (black_parrot, bp_be_top, bp_multi_top, swerv_wrapper, ariane136)

Means over seeds 1-10, off → on, all at GRT (5_1). fmax = ORFS timing__fmax (reg2reg, see #4583). GPL wirelength = 3_3 final HPWL, GRT wirelength = 5_1 routed, placement runtime = 3_1..3_5.

design	fmax (GHz)	setup WS	setup TNS	GPL WL	GRT WL	placement runtime
asap7/coralnpu	0.496 → 0.509 (+2.49%)	-2005 → -1957 ps	-10293190 → -10590840 ps	+1.1%	+1.7%	-5%
nangate45/ariane136	4.518 → 3.973 (-12.06%)*	+0.277 → +0.360 ns	0 → 0	-1.0%	-0.7%	0%
nangate45/black_parrot	0.111 → 0.111 (-0.05%)	-3.040 → -3.045 ns	-3.040 → -3.045 ns	-2.5%	-1.9%	-8%
nangate45/bp_be_top	0.449 → 0.456 (+1.62%)	+0.007 → +0.008 ns	0 → 0	-5.6%	-3.8%	-4%
nangate45/bp_multi_top	0.287 → 0.288 (+0.20%)	-0.083 → -0.076 ns	-0.083 → -0.076 ns	-3.3%	-2.8%	-3%
nangate45/swerv	1.012 → 1.082 (+6.86%)	-0.602 → -0.581 ns	-254.7 → -265.5 ns	+4.0%	+4.2%	-3%
nangate45/swerv_wrapper	0.429 → 0.433 (+0.86%)	-0.329 → -0.309 ns	-340.1 → -332.3 ns	-8.0%	-6.7%	-4%
ihp-sg13g2/gcd	0.557 → 0.559 (+0.47%)	-0.301 → -0.293 ns	-9.54 → -8.90 ns	-10.6%	-4.2%	<1 s
ihp-sg13g2/ibex	0.142 → 0.142 (+0.17%)	+0.028 → +0.095 ns	-0.08 → 0 ns	-1.5%	-2.8%	-4%
ihp-sg13g2/riscv32i	0.254 → 0.254 (-0.13%)	-1.939 → -1.944 ns	-1794 → -1779 ns	-1.8%	-1.3%	-3%
ihp-sg13g2/spi	1.123 → 1.131 (+0.74%)	-0.091 → -0.084 ns	-0.94 → -0.91 ns	+10.5%	+8.5%	<1 s

* ariane136's timing__fmax is the virtual IO clock vclk; core_clock fmax goes 0.177 → 0.180 GHz.

Disabled (13):

• asap7: cva6 (placement runtime +3%), swerv_wrapper
• nangate45: ariane133, bp_fe_top (TNS -41%), cva6, mempool_group, tinyRocket
• sky130hd: chameleon (GRT wirelength +17%, antenna diodes +22%), microwatt (fmax -1.4%, ±10% across seeds)
• gf180: ibex, riscv32i (fmax -3%), uart-blocks
• ihp-sg13g2: jpeg

Not measured (1): nangate45/bp_quad, floorplan fails with PDN-0179 on both arms.

[gemini-code-assist]

Code Review

This pull request enables the GPL_PLACE_IOS option by setting export GPL_PLACE_IOS = 1 across multiple design configuration files (config.mk) for various platforms, including asap7, ihp-sg13g2, and nangate45. There are no review comments, and I have no feedback to provide.