Merge pull request #8524 from gadfort/dpl-remove-pad-fillers

dpl: remove pad and block masters from filler placement before placing

Author: gadfort

.gitignore

@@ -65,3 +65,4 @@ bazel-OpenROAD
 projectview.bazelproject
 .bsp/
 .bazelbsp/
+/buildifier

src/dpl/include/dpl/Opendp.h

@@ -277,6 +277,7 @@ class Opendp
   DbuPt initialLocation(const Node* cell, bool padded) const;
   int disp(const Node* cell) const;
   // Place fillers
+  dbMasterSeq filterFillerMasters(const dbMasterSeq& filler_masters) const;
   MasterByImplant splitByImplant(const dbMasterSeq& filler_masters);
   void setGridCells();
   dbMasterSeq& gapFillers(dbTechLayer* implant,

src/dpl/src/FillerPlacement.cpp

@@ -49,6 +49,47 @@ Opendp::MasterByImplant Opendp::splitByImplant(
   return mapping;
 }
 
+dbMasterSeq Opendp::filterFillerMasters(const dbMasterSeq& filler_masters) const
+{
+  // Remove fillers that cannot be used
+  dbMasterSeq filtered_masters = filler_masters;
+
+  if (logger_->debugCheck(DPL, "filler", 2)) {
+    debugPrint(logger_,
+               DPL,
+               "filler",
+               1,
+               "Starting fillers: {}",
+               filtered_masters.size()) for (auto* master : filtered_masters)
+    {
+      debugPrint(logger_, DPL, "filler", 2, "    {}", master->getName());
+    }
+  }
+
+  // Remove fillers with PAD or BLOCK classes
+  filtered_masters.erase(std::remove_if(filtered_masters.begin(),
+                                        filtered_masters.end(),
+                                        [](dbMaster* master) -> bool {
+                                          return master->isPad()
+                                                 || master->isBlock();
+                                        }),
+                         filtered_masters.end());
+
+  if (logger_->debugCheck(DPL, "filler", 2)) {
+    debugPrint(logger_,
+               DPL,
+               "filler",
+               1,
+               "Final filterered fillers: {}",
+               filtered_masters.size()) for (auto* master : filtered_masters)
+    {
+      debugPrint(logger_, DPL, "filler", 2, "    {}", master->getName());
+    }
+  }
+
+  return filtered_masters;
+}
+
 void Opendp::fillerPlacement(const dbMasterSeq& filler_masters,
                              const char* prefix,
                              bool verbose)
@@ -58,7 +99,9 @@ void Opendp::fillerPlacement(const dbMasterSeq& filler_masters,
     adjustNodesOrient();
   }
 
-  auto filler_masters_by_implant = splitByImplant(filler_masters);
+  const auto filtered_masters = filterFillerMasters(filler_masters);
+
+  auto filler_masters_by_implant = splitByImplant(filtered_masters);
 
   for (auto& [layer, masters] : filler_masters_by_implant) {
     std::sort(masters.begin(),

src/dpl/test/BUILD

@@ -33,6 +33,7 @@ COMPULSORY_TESTS = [
     "fillers8",
     "fillers9",
     "fillers9_verbose",
+    "fillers10",
     "fragmented_row01",
     "fragmented_row02",
     "fragmented_row03",
@@ -193,6 +194,9 @@ filegroup(
             "fillers1": [
                 "simple01.def",
             ],
+            "fillers10": [
+                "simple09.def",
+            ],
             "fillers2": [
                 "simple01.def",
             ],

src/dpl/test/CMakeLists.txt

@@ -34,6 +34,7 @@ or_integration_tests(
     fillers8
     fillers9
     fillers9_verbose
+    fillers10
     fragmented_row01
     fragmented_row02
     fragmented_row03

src/dpl/test/fillers10.defok

@@ -0,0 +1,22 @@
+[INFO ODB-0227] LEF file: Nangate45/Nangate45.lef, created 22 layers, 27 vias, 135 library cells
+[INFO ODB-0227] LEF file: Nangate45/fakeram45_64x7.lef, created 1 library cells
+[INFO ODB-0128] Design: single_cell
+[INFO ODB-0130]     Created 2 pins.
+[INFO ODB-0131]     Created 1 components and 4 component-terminals.
+[INFO ODB-0132]     Created 2 special nets and 2 connections.
+[INFO ODB-0133]     Created 2 nets and 2 connections.
+Placement Analysis
+---------------------------------
+total displacement       2003.3 u
+average displacement     2003.3 u
+max displacement         2003.3 u
+original HPWL            2002.3 u
+legalized HPWL           6009.1 u
+delta HPWL                  200 %
+
+[INFO DPL-0001] Placed 1128 filler instances.
+Filler usage:
+  FILLCELL_X1:     1
+  FILLCELL_X32: 1124
+  FILLCELL_X8:     3
+No differences found.

src/dpl/test/fillers10.ok

@@ -0,0 +1,12 @@
+# filler_placement for simple09 with block included as filler
+source "helpers.tcl"
+read_lef Nangate45/Nangate45.lef
+read_lef Nangate45/fakeram45_64x7.lef
+read_def simple09.def
+detailed_placement
+filler_placement -verbose "fake* FILL*"
+check_placement
+
+set def_file [make_result_file fillers10.def]
+write_def $def_file
+diff_file $def_file fillers10.defok