dpl: remove independent rail checking from negotiation which seems incosistent with legacy rail checking at checkRowPowerCompatible

Signed-off-by: Augusto Berndt <augusto.berndt@precisioninno.com>

Author: gudeh

src/dpl/src/NegotiationLegalizer.cpp

@@ -1250,12 +1250,11 @@ RowRejection NegotiationLegalizer::rowRejectionReason(int rowIdx,
       return RowRejection::kDeadRow;
     }
   }
-  // Bottom-row site type must match the cell's declared site. Upper rows
-  // of a multi-height cell legitimately span heterogeneous row types in
-  // hybrid-row designs (the cell's master declares one site, matching the
-  // bottom row, and is designed to cover rows of differing types above).
-  // Rail/power compatibility is enforced separately by the rail check
-  // below; this matches CheckPlacement's first-row-only site check.
+  // Bottom-row site type must match the cell's declared site. The returned
+  // orientation also implicitly handles rail alignment for single-row
+  // cells: R0 vs MX flips the cell's power pins so a VSS-bottom master can
+  // legally land on an MX (VDD-bottom) row, etc. Matches the first-row-only
+  // site check in Opendp::checkPixels / CheckPlacement.
   if (cell.db_inst != nullptr && opendp_ && opendp_->grid_) {
     odb::dbSite* site = cell.db_inst->getMaster()->getSite();
     if (site != nullptr
@@ -1264,18 +1263,21 @@ RowRejection NegotiationLegalizer::rowRejectionReason(int rowIdx,
       return RowRejection::kSiteTypeMismatch;
     }
   }
-  const NLPowerRailType row_bottom_rail = row_rail_[rowIdx];
-  const bool bottom_rail_ok
-      = (row_bottom_rail == cell.rail_type)
-        || (cell.flippable && row_bottom_rail == cell.rail_type_flipped);
-  if (!bottom_rail_ok) {
-    return RowRejection::kRailMismatch;
-  }
-  // For multi-row cells, also verify the master's power-pin stack lines
-  // up with the PDN rail stack across the entire span. Mirrors the check
-  // in Opendp::isPlacementLegal(); without it, the bottom-rail check
-  // above can let wrong-parity landings through on cells whose top and
-  // bottom rails differ.
+  //
+  // const NLPowerRailType row_bottom_rail = row_rail_[rowIdx];
+  // const bool bottom_rail_ok
+  //     = (row_bottom_rail == cell.rail_type)
+  //       || (cell.flippable && row_bottom_rail == cell.rail_type_flipped);
+  // if (!bottom_rail_ok) {
+  //   return RowRejection::kRailMismatch;
+  // }
+  //
+
+  // For multi-row cells, verify the master's power-pin stack lines up with
+  // the PDN rail stack across the entire span. Mirrors the check in
+  // Opendp::checkPixels (which diamond search ultimately uses); the
+  // single-row rail constraint is already captured by getSiteOrientation
+  // above (orientation encodes which power pin sits at the bottom).
   if (cell.db_inst != nullptr && network_ != nullptr && opendp_ != nullptr) {
     if (Node* node = network_->getNode(cell.db_inst)) {
       if (node->getMaster()->isMultiRow()

src/dpl/src/infrastructure/network.cxx

@@ -310,6 +310,13 @@ std::pair<int, int> getMasterPwrs(odb::dbMaster* master)
     }
     return Architecture::Row::Power_UNK;
   };
+  std::cout << "master:" << master->getName() 
+          << " height:" << master->getHeight()
+          << " top_has_pwr:" << top_has_pwr
+          << " top_has_gnd:" << top_has_gnd
+          << " bot_has_pwr:" << bot_has_pwr
+          << " bot_has_gnd:" << bot_has_gnd << std::endl;
+
   return {resolve(top_has_pwr, top_has_gnd), resolve(bot_has_pwr, bot_has_gnd)};
 }
 

src/dpl/test/neg.log

@@ -0,0 +1,49 @@
+OpenROAD 26Q2-1860-g5293d481c4 
+Features included (+) or not (-): +GPU +GUI +Python
+This program is licensed under the BSD-3 license. See the LICENSE file for details.
+Components of this program may be licensed under more restrictive licenses which must be honored.
+[INFO ODB-0227] LEF file: Nangate45/Nangate45.lef, created 22 layers, 27 vias, 135 library cells
+[INFO ODB-0227] LEF file: Nangate45/fake_macros.lef, created 11 library cells
+[INFO ODB-0128] Design: top
+[INFO ODB-0131]     Created 7 components and 35 component-terminals.
+master:MOCK_DOUBLE height:5600 top_has_pwr:0 top_has_gnd:0 bot_has_pwr:0 bot_has_gnd:0
+master:MOCK_QUAD height:11200 top_has_pwr:0 top_has_gnd:0 bot_has_pwr:0 bot_has_gnd:0
+master:MOCK_SINGLE height:2800 top_has_pwr:0 top_has_gnd:0 bot_has_pwr:0 bot_has_gnd:0
+master:MOCK_TRIPLE height:8400 top_has_pwr:0 top_has_gnd:0 bot_has_pwr:0 bot_has_gnd:0
+[INFO DPL-0388] Cell height distribution (4 unique micron height(s)):
+[INFO DPL-0389]   height 1.400 um: 3 cells
+[INFO DPL-0389]   height 2.800 um: 1 cells
+[INFO DPL-0389]   height 4.200 um: 1 cells
+[INFO DPL-0389]   height 5.600 um: 2 cells
+[INFO DPL-0006] Core area: 108.53 um^2, Instances area: 17.02 um^2, Utilization: 15.7%
+[INFO DPL-0007] All instances area (incl. macros/pads/fixed): 17.02 um^2, Utilization: 15.7%
+[INFO DPL-0005] Diamond search max displacement: +/- 500 sites horizontally, +/- 100 rows vertically.
+[INFO DPL-1102] Legalizing using negotiation legalizer.
+[INFO DPL-1103] NegotiationLegalizer search window: +/-20 sites horizontally, +/-5 rows vertically.
+[INFO DPL-1104] NegotiationLegalizer DRC penalty: 5.
+[INFO DPL-0392] Negotiation cell height distribution (4 unique row-count(s)):
+[INFO DPL-0393]   height 1 row(s): 3 cells
+[INFO DPL-0393]   height 2 row(s): 1 cells
+[INFO DPL-0393]   height 3 row(s): 1 cells
+[INFO DPL-0393]   height 4 row(s): 2 cells
+Pause after initFromDb.
+Committing post-init positions to odb; debug move line drawings will exclude gpl-to-init displacement.
+Pause after initialization: Abacus skipped.
+Pause before negotiation phase 1.
+          |      Total |  Illegal |  Illegal
+Iteration | Violations |    Cells |    Sites
+---------------------------------------------
+[neg-search 1/50] q2 master=MOCK_QUAD site=QuadHeightSite extended_search_rows.size=3 seed_valid=true nearest_below_step=4 nearest_above_step=-1 rej_oob=32 rej_dead=0 rej_site=6 rej_rail=0 win_y=[0,12) (rows=12, below_cell=0, above_cell=8) win_x=[-14,27) (sites=41, half=20) row_search_cap=20 row_search_window=5 cell.height=4 cell.width=4 max_disp_y=100 rail_type=kVss rail_type_flipped=kVdd flippable=true fence_id=-1 init_y=0 init_x=6 cur_y=0 cur_x=6
+Pause at placing of cell q2. orig=(2280,0) target=(2280,11200) dbu. rowidx=4.
+[neg-search 2/50] t1 master=MOCK_TRIPLE site=TripleHeightSite extended_search_rows.size=4 seed_valid=true nearest_below_step=3 nearest_above_step=-1 rej_oob=21 rej_dead=0 rej_site=6 rej_rail=0 win_y=[0,12) (rows=12, below_cell=0, above_cell=9) win_x=[-13,28) (sites=41, half=20) row_search_cap=15 row_search_window=5 cell.height=3 cell.width=4 max_disp_y=100 rail_type=kVss rail_type_flipped=kVdd flippable=true fence_id=-1 init_y=0 init_x=7 cur_y=0 cur_x=7
+Pause at placing of cell t1. orig=(2660,0) target=(380,0) dbu. rowidx=0.
+[neg-search 3/50] q1 master=MOCK_QUAD site=QuadHeightSite extended_search_rows.size=3 seed_valid=true nearest_below_step=4 nearest_above_step=-1 rej_oob=32 rej_dead=0 rej_site=6 rej_rail=0 win_y=[0,12) (rows=12, below_cell=0, above_cell=8) win_x=[-15,26) (sites=41, half=20) row_search_cap=20 row_search_window=5 cell.height=4 cell.width=4 max_disp_y=100 rail_type=kVss rail_type_flipped=kVdd flippable=true fence_id=-1 init_y=0 init_x=5 cur_y=0 cur_x=5
+Pause at placing of cell q1. orig=(1900,0) target=(1900,0) dbu. rowidx=0.
+[neg-search 4/50] d1 master=MOCK_DOUBLE site=DoubleHeightSite extended_search_rows.size=6 seed_valid=true nearest_below_step=2 nearest_above_step=-1 rej_oob=10 rej_dead=0 rej_site=5 rej_rail=0 win_y=[0,12) (rows=12, below_cell=0, above_cell=10) win_x=[-12,29) (sites=41, half=20) row_search_cap=10 row_search_window=5 cell.height=2 cell.width=4 max_disp_y=100 rail_type=kVss rail_type_flipped=kVdd flippable=true fence_id=-1 init_y=0 init_x=8 cur_y=0 cur_x=8
+Pause at placing of cell d1. orig=(3040,0) target=(4940,0) dbu. rowidx=0.
+[neg-search 5/50] s2 master=MOCK_SINGLE site=FreePDK45_38x28_10R_NP_162NW_34O extended_search_rows.size=7 seed_valid=true nearest_below_step=1 nearest_above_step=1 rej_oob=4 rej_dead=0 rej_site=0 rej_rail=0 win_y=[0,7) (rows=7, below_cell=1, above_cell=5) win_x=[-11,30) (sites=41, half=20) row_search_cap=5 row_search_window=5 cell.height=1 cell.width=4 max_disp_y=100 rail_type=kVss rail_type_flipped=kVdd flippable=true fence_id=-1 init_y=1 init_x=9 cur_y=1 cur_x=9
+Pause at placing of cell s2. orig=(3420,2800) target=(3420,2800) dbu. rowidx=1.
+[neg-search 6/50] s1 master=MOCK_SINGLE site=FreePDK45_38x28_10R_NP_162NW_34O extended_search_rows.size=6 seed_valid=true nearest_below_step=1 nearest_above_step=-1 rej_oob=5 rej_dead=0 rej_site=0 rej_rail=0 win_y=[0,6) (rows=6, below_cell=0, above_cell=5) win_x=[-11,30) (sites=41, half=20) row_search_cap=5 row_search_window=5 cell.height=1 cell.width=4 max_disp_y=100 rail_type=kVss rail_type_flipped=kVdd flippable=true fence_id=-1 init_y=0 init_x=9 cur_y=0 cur_x=9
+Pause at placing of cell s1. orig=(3420,0) target=(3420,0) dbu. rowidx=0.
+[neg-search 7/50] s3 master=MOCK_SINGLE site=FreePDK45_38x28_10R_NP_162NW_34O extended_search_rows.size=8 seed_valid=true nearest_below_step=1 nearest_above_step=1 rej_oob=3 rej_dead=0 rej_site=0 rej_rail=0 win_y=[0,8) (rows=8, below_cell=2, above_cell=5) win_x=[-10,31) (sites=41, half=20) row_search_cap=5 row_search_window=5 cell.height=1 cell.width=4 max_disp_y=100 rail_type=kVss rail_type_flipped=kVdd flippable=true fence_id=-1 init_y=2 init_x=10 cur_y=2 cur_x=10
+Pause at placing of cell s3. orig=(3800,5600) target=(3800,5600) dbu. rowidx=2.

src/dpl/test/negotiation_quad_height.def

@@ -0,0 +1,41 @@
+VERSION 5.8 ;
+DIVIDERCHAR "/" ;
+BUSBITCHARS "[]" ;
+DESIGN top ;
+UNITS DISTANCE MICRONS 2000 ;
+DIEAREA ( 0 0 ) ( 13050 33600 ) ;
+ROW ROW_0 FreePDK45_38x28_10R_NP_162NW_34O 0 0 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_1 FreePDK45_38x28_10R_NP_162NW_34O 0 2800 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_2 FreePDK45_38x28_10R_NP_162NW_34O 0 5600 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_3 FreePDK45_38x28_10R_NP_162NW_34O 0 8400 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_4 FreePDK45_38x28_10R_NP_162NW_34O 0 11200 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_5 FreePDK45_38x28_10R_NP_162NW_34O 0 14000 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_6 FreePDK45_38x28_10R_NP_162NW_34O 0 16800 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_7 FreePDK45_38x28_10R_NP_162NW_34O 0 19600 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_8 FreePDK45_38x28_10R_NP_162NW_34O 0 22400 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_9 FreePDK45_38x28_10R_NP_162NW_34O 0 25200 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_10 FreePDK45_38x28_10R_NP_162NW_34O 0 28000 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_11 FreePDK45_38x28_10R_NP_162NW_34O 0 30800 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_D0 DoubleHeightSite 0 0 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_D1 DoubleHeightSite 0 5600 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_D2 DoubleHeightSite 0 11200 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_D3 DoubleHeightSite 0 16800 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_D4 DoubleHeightSite 0 22400 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_D5 DoubleHeightSite 0 28000 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_T0 TripleHeightSite 0 0 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_T1 TripleHeightSite 0 8400 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_T2 TripleHeightSite 0 16800 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_T3 TripleHeightSite 0 25200 FS DO 34 BY 1 STEP 380 0 ;
+ROW ROW_Q0 QuadHeightSite 0 0 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_Q1 QuadHeightSite 0 11200 N DO 34 BY 1 STEP 380 0 ;
+ROW ROW_Q2 QuadHeightSite 0 22400 N DO 34 BY 1 STEP 380 0 ;
+COMPONENTS 7 ;
+    - q1 MOCK_QUAD + PLACED ( 1900 0 ) N ;
+    - q2 MOCK_QUAD + PLACED ( 2280 0 ) N ;
+    - t1 MOCK_TRIPLE + PLACED ( 2660 0 ) N ;
+    - d1 MOCK_DOUBLE + PLACED ( 3040 0 ) N ;
+    - s1 MOCK_SINGLE + PLACED ( 3420 0 ) N ;
+    - s2 MOCK_SINGLE + PLACED ( 3420 2800 ) FS ;
+    - s3 MOCK_SINGLE + PLACED ( 3800 5600 ) N ;
+END COMPONENTS
+END DESIGN

src/dpl/test/negotiation_quad_height.tcl

@@ -0,0 +1,16 @@
+# Exercise the negotiation legalizer with a 4-row tall cell (MOCK_QUAD).
+# Overlapping multi-height cells (quad, triple, double, single) on the same
+# rows force the negotiation loop to resolve conflicts across cells whose
+# heights span up to four standard rows.
+source "helpers.tcl"
+read_lef Nangate45/Nangate45.lef
+read_lef Nangate45/fake_macros.lef
+read_def negotiation_quad_height.def
+set_debug_level DPL negtotiation 1
+dpl::detailed_placement_debug -deep_iterative -paint_negotiation_pixels
+detailed_placement
+check_placement
+
+set def_file [make_result_file negotiation_quad_height.def]
+write_def $def_file
+# diff_file negotiation_quad_height.defok $def_file

test/Nangate45/fake_macros.lef

@@ -132,6 +132,13 @@ SITE TripleHeightSite
 END TripleHeightSite
 
 
+SITE QuadHeightSite
+  SYMMETRY Y ;
+  CLASS core ;
+  SIZE 0.19 BY 5.6 ;
+END QuadHeightSite
+
+
 SITE HybridG
  SYMMETRY X Y ;
  CLASS core ;
@@ -258,6 +265,34 @@ MACRO MOCK_TRIPLE
   END VSS
 END MOCK_TRIPLE
 
+MACRO MOCK_QUAD
+  CLASS CORE ;
+  ORIGIN 0 0 ;
+  FOREIGN AND2_X1 0 0 ;
+  SIZE 0.76 BY 5.6 ;
+  SYMMETRY X Y ;
+  SITE QuadHeightSite ;
+  PIN A1
+    PORT
+      LAYER metal1 ;
+        RECT 0 0.1 0.1 0.2  ;
+    END
+  END A1
+  PIN A2
+    DIRECTION INPUT ;
+    PORT
+      LAYER metal1 ;
+        RECT 0 1.8 0.1 1.9  ;
+    END
+  END A2
+  PIN ZN
+  END ZN
+  PIN VDD
+  END VDD
+  PIN VSS
+  END VSS
+END MOCK_QUAD
+
 MACRO MOCK_HYBRID_A
   CLASS CORE ;
   ORIGIN 0 0 ;