odb: support DEF virtual route points

src/odb/src/defin/definNet.cpp

@@ -233,6 +233,7 @@ void definNet::wire(dbWireType type)
 
   _wire_type = type;
   _taper_rule = nullptr;
+  _prev_junction_id = -1;
 }
 
 void definNet::path(const char* layer_name)
@@ -278,6 +279,7 @@ void definNet::pathBegin(const char* layer_name)
   } else {
     _wire_encoder.newPath(_cur_layer, _wire_type);
   }
+  _prev_junction_id = -1;
 }
 
 void definNet::pathTaper(const char* layer)
@@ -312,7 +314,7 @@ void definNet::pathPoint(int x, int y)
   _prev_x = dbdist(x);
   _prev_y = dbdist(y);
 
-  _wire_encoder.addPoint(_prev_x, _prev_y);
+  _prev_junction_id = _wire_encoder.addPoint(_prev_x, _prev_y);
 }
 
 void definNet::pathPoint(int x, int y, int ext)
@@ -324,7 +326,38 @@ void definNet::pathPoint(int x, int y, int ext)
   _prev_x = dbdist(x);
   _prev_y = dbdist(y);
 
-  _wire_encoder.addPoint(_prev_x, _prev_y, dbdist(ext));
+  _prev_junction_id = _wire_encoder.addPoint(_prev_x, _prev_y, dbdist(ext));
+}
+
+void definNet::pathVirtualPoint(int x, int y)
+{
+  if (_wire == nullptr) {
+    return;
+  }
+
+  if (_cur_layer == nullptr || _prev_junction_id < 0) {
+    _logger->warn(utl::ODB,
+                  469,
+                  "error: VIRTUAL routing point in net {} does not follow a "
+                  "routing point",
+                  _cur_net->getName());
+    ++_errors;
+    dbWire::destroy(_wire);
+    _wire = nullptr;
+    return;
+  }
+
+  if (_taper_rule) {
+    _wire_encoder.newPathVirtualWire(
+        _prev_junction_id, _cur_layer, _wire_type, _taper_rule);
+  } else {
+    _wire_encoder.newPathVirtualWire(
+        _prev_junction_id, _cur_layer, _wire_type);
+  }
+
+  _prev_x = dbdist(x);
+  _prev_y = dbdist(y);
+  _prev_junction_id = _wire_encoder.addPoint(_prev_x, _prev_y);
 }
 
 void definNet::getUniqueViaName(std::string& viaName)

src/odb/src/defin/definNet.h

@@ -36,6 +36,7 @@ class definNet : public definBase
   dbTechLayerRule* _taper_rule{nullptr};
   dbTechNonDefaultRule* _non_default_rule{nullptr};
   dbTechNonDefaultRule* _rule_for_path{nullptr};
+  int _prev_junction_id{-1};
   std::map<std::string, dbVia*> _rotated_vias;
 
   void getUniqueViaName(std::string& viaName);
@@ -59,6 +60,7 @@ class definNet : public definBase
   void pathTaperRule(const char* layer, const char* rule);
   void pathPoint(int x, int y);
   void pathPoint(int x, int y, int ext);
+  void pathVirtualPoint(int x, int y);
   void pathVia(const char* via);
   void pathVia(const char* via, dbOrientType orient);
   void pathRect(int deltaX1, int deltaY1, int deltaX2, int deltaY2);

src/odb/src/defin/definReader.cpp

@@ -857,9 +857,13 @@ int definReader::netCallback(DefParser::defrCallbackType_e /* unused: type */,
             break;
           }
 
-          case DefParser::DEFIPATH_VIRTUALPOINT:
-            UNSUPPORTED("VIRTUAL in net's routing is unsupported");
+          case DefParser::DEFIPATH_VIRTUALPOINT: {
+            int x;
+            int y;
+            path->getVirtualPoint(&x, &y);
+            netR->pathVirtualPoint(x, y);
             break;
+          }
 
           case DefParser::DEFIPATH_MASK:
             netR->pathColor(path->getMask());

src/odb/src/defout/defout_impl.cpp

@@ -1473,6 +1473,8 @@ void DefOut::Impl::writeWire(dbWire* wire)
   int path_cnt = 0;
   int prev_x = std::numeric_limits<int>::max();
   int prev_y = std::numeric_limits<int>::max();
+  int prev_junction_id = -1;
+  bool virtual_point = false;
 
   for (decode.begin(wire);;) {
     dbWireDecoder::OpCode opcode = decode.next();
@@ -1484,6 +1486,12 @@ void DefOut::Impl::writeWire(dbWire* wire)
       case dbWireDecoder::SHORT:
       case dbWireDecoder::VWIRE:
       case dbWireDecoder::JUNCTION: {
+        if (opcode == dbWireDecoder::VWIRE
+            && decode.getJunctionValue() == prev_junction_id) {
+          virtual_point = true;
+          break;
+        }
+
         layer = decode.getLayer();
         const std::string lname = layer->getName();
 
@@ -1504,6 +1512,8 @@ void DefOut::Impl::writeWire(dbWire* wire)
 
         prev_wire_type = wire_type;
         point_cnt = 0;
+        prev_junction_id = -1;
+        virtual_point = false;
         ++path_cnt;
         break;
       }
@@ -1518,6 +1528,15 @@ void DefOut::Impl::writeWire(dbWire* wire)
           *_out << "\n    ";
         }
 
+        if (virtual_point) {
+          *_out << " VIRTUAL ( " << x << " " << y << " )";
+          virtual_point = false;
+          prev_x = x;
+          prev_y = y;
+          prev_junction_id = decode.getJunctionId();
+          break;
+        }
+
         std::string mask_statement;
         if (point_cnt % 2 == 0 && color) {
           mask_statement = fmt::format("MASK {}", color.value());
@@ -1533,6 +1552,7 @@ void DefOut::Impl::writeWire(dbWire* wire)
 
         prev_x = x;
         prev_y = y;
+        prev_junction_id = decode.getJunctionId();
         break;
       }
 
@@ -1547,6 +1567,15 @@ void DefOut::Impl::writeWire(dbWire* wire)
           *_out << "\n    ";
         }
 
+        if (virtual_point) {
+          *_out << " VIRTUAL ( " << x << " " << y << " )";
+          virtual_point = false;
+          prev_x = x;
+          prev_y = y;
+          prev_junction_id = decode.getJunctionId();
+          break;
+        }
+
         if (point_cnt == 1) {
           *_out << " ( " << x << " " << y << " " << ext << " )";
         } else if ((x == prev_x) && (y == prev_y)) {
@@ -1559,6 +1588,7 @@ void DefOut::Impl::writeWire(dbWire* wire)
 
         prev_x = x;
         prev_y = y;
+        prev_junction_id = decode.getJunctionId();
         break;
       }
 

src/odb/test/BUILD

@@ -188,6 +188,7 @@ COMPULSORY_TESTS = [
     "read_3dbx",
     "read_db",
     "read_def",
+    "read_def_virtual",
     "read_def58",
     "read_lef",
     "read_zipped",
@@ -217,6 +218,7 @@ COMPULSORY_TESTS = [
 
 PASSFAIL_TESTS = [
     # pass-fail
+    "read_def_virtual_invalid",
     "test_block",
     "test_bterm",
     "test_destroy",
@@ -303,6 +305,8 @@ filegroup(
         "data/rounding.def",
         "data/sky130_fd_sc_hd__inv_1.gds",
         "data/sky130hd_multi_patterned.def",
+        "data/virtual_route.def",
+        "data/virtual_route_invalid.def",
         "dump_netlists.tcl",
         "dump_netlists_withfill.tcl",
         "fake_macros.def",

src/odb/test/CMakeLists.txt

@@ -44,6 +44,7 @@ or_integration_tests(
     read_3dbx
     read_db
     read_def
+    read_def_virtual
     read_def58
     read_lef
     read_zipped
@@ -71,6 +72,7 @@ or_integration_tests(
     write_macro_placement
   PASSFAIL_TESTS
     cpp_tests
+    read_def_virtual_invalid
     test_block
     test_bterm
     test_destroy

src/odb/test/data/virtual_route.def

@@ -0,0 +1,14 @@
+VERSION 5.8 ;
+DIVIDERCHAR "/" ;
+BUSBITCHARS "[]" ;
+DESIGN virtual_route ;
+UNITS DISTANCE MICRONS 2000 ;
+DIEAREA ( 0 0 ) ( 20000 20000 ) ;
+
+NETS 1 ;
+- net1
+  + ROUTED metal1 ( 0 0 ) ( 2000 0 ) VIRTUAL ( 2000 1000 )
+    RECT ( -500 -500 500 500 ) ( 2000 2000 ) ;
+END NETS
+
+END DESIGN

src/odb/test/data/virtual_route_invalid.def

@@ -0,0 +1,13 @@
+VERSION 5.8 ;
+DIVIDERCHAR "/" ;
+BUSBITCHARS "[]" ;
+DESIGN virtual_route_invalid ;
+UNITS DISTANCE MICRONS 2000 ;
+DIEAREA ( 0 0 ) ( 20000 20000 ) ;
+
+NETS 1 ;
+- net1
+  + ROUTED metal1 M2_M1_via VIRTUAL ( 2000 1000 ) ;
+END NETS
+
+END DESIGN

src/odb/test/read_def_virtual.ok

@@ -0,0 +1,16 @@
+[INFO ODB-0388] unsupported contactResistance property for layer contact :"10.5"
+[INFO ODB-0388] unsupported contactResistance property for layer via1 :"5.69"
+[WARNING ODB-0423] LEF58_REGION layer via1R1 ignored
+[INFO ODB-0388] unsupported contactResistance property for layer via2 :"11.39"
+[INFO ODB-0388] unsupported contactResistance property for layer via3 :"16.73"
+[INFO ODB-0388] unsupported contactResistance property for layer via4 :"21.44"
+[INFO ODB-0388] unsupported contactResistance property for layer via5 :"24.08"
+[INFO ODB-0388] unsupported contactResistance property for layer via6 :"11.39"
+[INFO ODB-0388] unsupported contactResistance property for layer via7 :"5.69"
+[INFO ODB-0388] unsupported contactResistance property for layer via8 :"16.73"
+[INFO ODB-0388] unsupported contactResistance property for layer via9 :"21.44"
+[INFO ODB-0227] LEF file: data/gscl45nm.lef, created 22 layers, 14 vias, 33 library cells
+[INFO ODB-0128] Design: virtual_route
+[INFO ODB-0133]     Created 1 nets and 0 connections.
+Summary 3 / 3 (100% pass)
+pass

src/odb/test/read_def_virtual.tcl

@@ -0,0 +1,44 @@
+source "helpers.tcl"
+
+read_lef "data/gscl45nm.lef"
+read_def "data/virtual_route.def"
+
+set block [ord::get_db_block]
+set net [$block findNet "net1"]
+set wire [$net getWire]
+
+set decoder [odb::dbWireDecoder]
+$decoder begin $wire
+
+set ops {}
+set points {}
+while { 1 } {
+  set op [$decoder next]
+  if { $op == $odb::dbWireDecoder_END_DECODE } {
+    break
+  }
+  if { $op == $odb::dbWireDecoder_PATH } {
+    lappend ops "PATH"
+  } elseif { $op == $odb::dbWireDecoder_POINT } {
+    lappend ops "POINT"
+    lappend points [$decoder getPoint]
+  } elseif { $op == $odb::dbWireDecoder_VWIRE } {
+    lappend ops "VWIRE"
+  } elseif { $op == $odb::dbWireDecoder_RECT } {
+    lappend ops "RECT"
+  }
+}
+
+check "wire opcode sequence" {join $ops " "} "PATH POINT POINT VWIRE POINT RECT POINT"
+check "wire points" {join $points " "} "0 0 2000 0 2000 1000 2000 2000"
+
+set out_def [make_result_file "read_def_virtual.def"]
+write_def $out_def
+set stream [open $out_def r]
+set def_text [read $stream]
+close $stream
+check "write_def preserves virtual point" {
+  expr {[string first "VIRTUAL ( 2000 1000 )" $def_text] >= 0}
+} 1
+
+exit_summary

src/odb/test/read_def_virtual_invalid.tcl

@@ -0,0 +1,16 @@
+source "helpers.tcl"
+
+read_lef "data/gscl45nm.lef"
+
+set status [catch { read_def "data/virtual_route_invalid.def" } msg]
+if { $status != 1 } {
+  puts "fail: read_def accepted VIRTUAL without a prior routing point"
+  exit 1
+}
+
+if { $msg != "ODB-0421" } {
+  puts "fail: unexpected error: $msg"
+  exit 1
+}
+
+puts "pass"