Merge pull request #8367 from gadfort/pdn-fix-edge-connect

pdn: fix pad edge connections

Author: maliberty

src/pdn/src/grid.cpp

@@ -1295,6 +1295,13 @@ void CoreGrid::setupDirectConnect(
       if (pad_connect->canConnect()) {
         straps.insert(pad_connect.get());
         addStrap(std::move(pad_connect));
+      } else {
+        debugPrint(getLogger(),
+                   utl::PDN,
+                   "Pad",
+                   2,
+                   "Rejecting pad cell pin {} due to lack of connectivity",
+                   iterm->getName())
       }
     }
   }

src/pdn/src/straps.cpp

@@ -614,6 +614,14 @@ void PadDirectConnectionStraps::initialize(ConnectionType type)
       pins_ = getPinsFormingRing();
       break;
   }
+
+  debugPrint(getLogger(),
+             utl::PDN,
+             "Pad",
+             2,
+             "{} has {} pins",
+             getName(),
+             pins_.size());
 }
 
 std::map<odb::dbTechLayer*, std::vector<odb::dbBox*>>
@@ -653,8 +661,6 @@ std::vector<odb::dbBox*> PadDirectConnectionStraps::getPinsFacingCore()
 
   const bool is_horizontal = is_west || is_east;
 
-  std::vector<odb::dbBox*> pins;
-
   auto pins_by_layer = getPinsByLayer();
   if (!layers_.empty()) {
     // remove unspecified layers
@@ -669,37 +675,6 @@ std::vector<odb::dbBox*> PadDirectConnectionStraps::getPinsFacingCore()
     }
   }
 
-  // check for pin directions
-  bool has_horizontal_pins = false;
-  bool has_vertical_pins = false;
-  for (const auto& [layer, layer_pins] : pins_by_layer) {
-    if (layer->getDirection() == odb::dbTechLayerDir::HORIZONTAL) {
-      has_horizontal_pins = true;
-    }
-    if (layer->getDirection() == odb::dbTechLayerDir::VERTICAL) {
-      has_vertical_pins = true;
-    }
-  }
-
-  const bool has_multiple_directions = has_horizontal_pins && has_vertical_pins;
-
-  for (const auto& [layer, layer_pins] : pins_by_layer) {
-    if (has_multiple_directions) {
-      // only add pins that would yield correct routing directions,
-      // otherwise keep non-preferred directions too
-      if (is_horizontal) {
-        if (layer->getDirection() != odb::dbTechLayerDir::HORIZONTAL) {
-          continue;
-        }
-      } else {
-        if (layer->getDirection() != odb::dbTechLayerDir::VERTICAL) {
-          continue;
-        }
-      }
-    }
-    pins.insert(pins.end(), layer_pins.begin(), layer_pins.end());
-  }
-
   const odb::dbTransform transform = inst->getTransform();
 
   // remove all pins that do not face the core
@@ -730,8 +705,52 @@ std::vector<odb::dbBox*> PadDirectConnectionStraps::getPinsFacingCore()
     };
   }
 
-  pins.erase(std::remove_if(pins.begin(), pins.end(), std::move(remove_func)),
-             pins.end());
+  for (auto& [layer, layerpins] : pins_by_layer) {
+    layerpins.erase(
+        std::remove_if(layerpins.begin(), layerpins.end(), remove_func),
+        layerpins.end());
+  }
+
+  for (auto itr = pins_by_layer.begin(); itr != pins_by_layer.end();) {
+    if (itr->second.empty()) {
+      // remove empty layer
+      itr = pins_by_layer.erase(itr);
+    } else {
+      itr++;
+    }
+  }
+
+  // check for pin directions
+  bool has_horizontal_pins = false;
+  bool has_vertical_pins = false;
+  for (const auto& [layer, layer_pins] : pins_by_layer) {
+    if (layer->getDirection() == odb::dbTechLayerDir::HORIZONTAL) {
+      has_horizontal_pins = true;
+    }
+    if (layer->getDirection() == odb::dbTechLayerDir::VERTICAL) {
+      has_vertical_pins = true;
+    }
+  }
+
+  const bool has_multiple_directions = has_horizontal_pins && has_vertical_pins;
+
+  std::vector<odb::dbBox*> pins;
+  for (const auto& [layer, layer_pins] : pins_by_layer) {
+    if (has_multiple_directions) {
+      // only add pins that would yield correct routing directions,
+      // otherwise keep non-preferred directions too
+      if (is_horizontal) {
+        if (layer->getDirection() != odb::dbTechLayerDir::HORIZONTAL) {
+          continue;
+        }
+      } else {
+        if (layer->getDirection() != odb::dbTechLayerDir::VERTICAL) {
+          continue;
+        }
+      }
+    }
+    pins.insert(pins.end(), layer_pins.begin(), layer_pins.end());
+  }
 
   if (!pins.empty()) {
     type_ = ConnectionType::Edge;

src/pdn/test/BUILD

@@ -99,6 +99,7 @@ COMPULSORY_TESTS = [
     "pads_black_parrot_max_width",
     "pads_black_parrot_no_connect",
     "pads_black_parrot_offset",
+    "pads_connect_from_non_pref_edge",
     "power_switch",
     "power_switch_cut_rows",
     "power_switch_daisy",
@@ -176,6 +177,10 @@ filegroup(
         "asap7_vias/asap7sc7p5t_27_R_1x.lef",
         "asap7_vias/floorplan.def",
         "asap7_vias/floorplan_repair.def",
+        "gf180/gf180mcu_6LM_1TM_9K_7t_tech.lef",
+        "gf180/gf180mcu_fd_io.lef",
+        "gf180/gf180mcu_fd_sc_mcu7t5v0.lef",
+        "gf180_data/floorplan.def",
         "helpers.tcl",
         "nangate_bsg_black_parrot/Nangate45_maxwidth.lef",
         "nangate_bsg_black_parrot/dummy_pads.lef",

src/pdn/test/CMakeLists.txt

@@ -98,6 +98,7 @@ or_integration_tests(
     pads_black_parrot_max_width
     pads_black_parrot_no_connect
     pads_black_parrot_offset
+    pads_connect_from_non_pref_edge
     power_switch
     power_switch_cut_rows
     power_switch_daisy

src/pdn/test/gf180

@@ -0,0 +1 @@
+../../../test/gf180