From 2a115ebd19894b025d3150d17f3e332d46c3aea9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matthias=20K=C3=B6fferlein?= <matthias@koefferlein.de>
Date: Sat, 12 Feb 2022 17:04:47 +0100
Subject: [PATCH] Fixed #971 (double compare fails in LVS) (#1001)

---
 src/lvs/unit_tests/lvsSimpleTests.cc       |   5 +
 src/tl/tl/tlObject.cc                      |   4 +
 src/tl/unit_tests/tlObjectTests.cc         |  17 +
 testdata/lvs/ringo_simple_compare2.cir     |  83 ++
 testdata/lvs/ringo_simple_compare2.lvs     |  77 ++
 testdata/lvs/ringo_simple_compare2.lvsdb.1 | 908 +++++++++++++++++++++
 testdata/lvs/ringo_simple_compare2.lvsdb.2 | 908 +++++++++++++++++++++
 7 files changed, 2002 insertions(+)
 create mode 100644 testdata/lvs/ringo_simple_compare2.cir
 create mode 100644 testdata/lvs/ringo_simple_compare2.lvs
 create mode 100644 testdata/lvs/ringo_simple_compare2.lvsdb.1
 create mode 100644 testdata/lvs/ringo_simple_compare2.lvsdb.2

diff --git a/src/lvs/unit_tests/lvsSimpleTests.cc b/src/lvs/unit_tests/lvsSimpleTests.cc
index f2386c72d..df95beedc 100644
--- a/src/lvs/unit_tests/lvsSimpleTests.cc
+++ b/src/lvs/unit_tests/lvsSimpleTests.cc
@@ -81,6 +81,11 @@ TEST(1_simple)
   run_test (_this, "ringo_simple", "ringo.gds");
 }
 
+TEST(1a_simple_double_compare)
+{
+  run_test (_this, "ringo_simple_compare2", "ringo.gds");
+}
+
 TEST(1b_simple_with_tolerance)
 {
   run_test (_this, "ringo_simple_with_tol", "ringo.gds");
diff --git a/src/tl/tl/tlObject.cc b/src/tl/tl/tlObject.cc
index 8f5e0c9df..54e2077a2 100644
--- a/src/tl/tl/tlObject.cc
+++ b/src/tl/tl/tlObject.cc
@@ -244,6 +244,10 @@ void WeakOrSharedPtr::reset_object ()
 
 void WeakOrSharedPtr::reset (Object *t, bool is_shared, bool is_event)
 {
+  if (t == mp_t) {
+    return;
+  }
+
   Object *to_delete = 0;
 
   {
diff --git a/src/tl/unit_tests/tlObjectTests.cc b/src/tl/unit_tests/tlObjectTests.cc
index fe75ff554..5aae67b30 100644
--- a/src/tl/unit_tests/tlObjectTests.cc
+++ b/src/tl/unit_tests/tlObjectTests.cc
@@ -74,12 +74,29 @@ TEST(1)
     EXPECT_EQ (sp0.get () == o, true);
     EXPECT_EQ (sp0 ? 1 : 0, 1);
 
+    //  installing the same pointer does not change anything
+    sp0.reset (sp.get ());
+    EXPECT_EQ (MyClass::instances (), 1);
+    EXPECT_EQ (sp0.get () == o, true);
+    EXPECT_EQ (sp.get () == o, true);
+
     delete o;
     o = 0;
     EXPECT_EQ (sp.get () == 0, true);
     EXPECT_EQ (sp ? 1 : 0, 0);
     EXPECT_EQ (sp0.get () == 0, true);
     EXPECT_EQ (sp0 ? 1 : 0, 0);
+    EXPECT_EQ (MyClass::instances (), 0);
+
+    MyClass *oo = new MyClass ();
+    sp.reset (oo);
+    EXPECT_EQ (MyClass::instances (), 1);
+    EXPECT_EQ (sp.get () == oo, true);
+    //  resetting again does not change anything
+    sp.reset (oo);
+    EXPECT_EQ (MyClass::instances (), 1);
+    EXPECT_EQ (sp.get () == oo, true);
+
   }
 
   EXPECT_EQ (MyClass::instances (), 0);
diff --git a/testdata/lvs/ringo_simple_compare2.cir b/testdata/lvs/ringo_simple_compare2.cir
new file mode 100644
index 000000000..761afb771
--- /dev/null
+++ b/testdata/lvs/ringo_simple_compare2.cir
@@ -0,0 +1,83 @@
+* Extracted by KLayout
+
+* cell RINGO
+* pin FB
+* pin VDD
+* pin OUT
+* pin ENABLE
+* pin VSS
+.SUBCKT RINGO 11 12 13 14 15
+* net 11 FB
+* net 12 VDD
+* net 13 OUT
+* net 14 ENABLE
+* net 15 VSS
+* cell instance $1 r0 *1 1.8,0
+X$1 12 1 15 12 11 14 15 ND2X1
+* cell instance $2 r0 *1 4.2,0
+X$2 12 2 15 12 1 15 INVX1
+* cell instance $3 r0 *1 6,0
+X$3 12 3 15 12 2 15 INVX1
+* cell instance $4 r0 *1 7.8,0
+X$4 12 4 15 12 3 15 INVX1
+* cell instance $5 r0 *1 9.6,0
+X$5 12 5 15 12 4 15 INVX1
+* cell instance $6 r0 *1 11.4,0
+X$6 12 6 15 12 5 15 INVX1
+* cell instance $7 r0 *1 13.2,0
+X$7 12 7 15 12 6 15 INVX1
+* cell instance $8 r0 *1 15,0
+X$8 12 8 15 12 7 15 INVX1
+* cell instance $9 r0 *1 16.8,0
+X$9 12 9 15 12 8 15 INVX1
+* cell instance $10 r0 *1 18.6,0
+X$10 12 10 15 12 9 15 INVX1
+* cell instance $11 r0 *1 20.4,0
+X$11 12 11 15 12 10 15 INVX1
+* cell instance $12 r0 *1 22.2,0
+X$12 12 13 15 12 11 15 INVX1
+.ENDS RINGO
+
+* cell INVX1
+* pin VDD
+* pin OUT
+* pin VSS
+* pin 
+* pin IN
+* pin SUBSTRATE
+.SUBCKT INVX1 1 2 3 4 5 6
+* net 1 VDD
+* net 2 OUT
+* net 3 VSS
+* net 5 IN
+* net 6 SUBSTRATE
+* device instance $1 r0 *1 0.85,5.8 PMOS
+M$1 1 5 2 4 PMOS L=0.25U W=1.5U AS=0.6375P AD=0.6375P PS=3.85U PD=3.85U
+* device instance $2 r0 *1 0.85,2.135 NMOS
+M$2 3 5 2 6 NMOS L=0.25U W=0.95U AS=0.40375P AD=0.40375P PS=2.75U PD=2.75U
+.ENDS INVX1
+
+* cell ND2X1
+* pin VDD
+* pin OUT
+* pin VSS
+* pin 
+* pin B
+* pin A
+* pin SUBSTRATE
+.SUBCKT ND2X1 1 2 3 4 5 6 7
+* net 1 VDD
+* net 2 OUT
+* net 3 VSS
+* net 5 B
+* net 6 A
+* net 7 SUBSTRATE
+* device instance $1 r0 *1 0.85,5.8 PMOS
+M$1 2 6 1 4 PMOS L=0.25U W=1.5U AS=0.6375P AD=0.3375P PS=3.85U PD=1.95U
+* device instance $2 r0 *1 1.55,5.8 PMOS
+M$2 1 5 2 4 PMOS L=0.25U W=1.5U AS=0.3375P AD=0.6375P PS=1.95U PD=3.85U
+* device instance $3 r0 *1 0.85,2.135 NMOS
+M$3 3 6 8 7 NMOS L=0.25U W=0.95U AS=0.40375P AD=0.21375P PS=2.75U PD=1.4U
+* device instance $4 r0 *1 1.55,2.135 NMOS
+M$4 8 5 2 7 NMOS L=0.25U W=0.95U AS=0.21375P AD=0.40375P PS=1.4U PD=2.75U
+.ENDS ND2X1
diff --git a/testdata/lvs/ringo_simple_compare2.lvs b/testdata/lvs/ringo_simple_compare2.lvs
new file mode 100644
index 000000000..abaeaff92
--- /dev/null
+++ b/testdata/lvs/ringo_simple_compare2.lvs
@@ -0,0 +1,77 @@
+
+source($lvs_test_source, "RINGO")
+
+report_lvs($lvs_test_target_lvsdb, true)
+
+target_netlist($lvs_test_target_cir, write_spice, "Extracted by KLayout")
+
+schematic("ringo.cir")
+
+deep
+
+# Drawing layers
+
+nwell       = input(1, 0)
+active      = input(2, 0)
+pplus       = input(3, 0)
+nplus       = input(4, 0)
+poly        = input(5, 0)
+contact     = input(8, 0)
+metal1      = input(9, 0)
+via1        = input(10, 0)
+metal2      = input(11, 0)
+
+# Bulk layer for terminal provisioning
+
+bulk        = polygon_layer
+
+# Computed layers
+
+active_in_nwell       = active & nwell
+pactive               = active_in_nwell & pplus
+pgate                 = pactive & poly
+psd                   = pactive - pgate
+ntie                  = active_in_nwell & nplus
+
+active_outside_nwell  = active - nwell
+nactive               = active_outside_nwell & nplus
+ngate                 = nactive & poly
+nsd                   = nactive - ngate
+ptie                  = active_outside_nwell & pplus
+
+# Device extraction
+
+# PMOS transistor device extraction
+extract_devices(mos4("PMOS"), { "SD" => psd, "G" => pgate, "W" => nwell, 
+                                "tS" => psd, "tD" => psd, "tG" => poly, "tW" => nwell })
+
+# NMOS transistor device extraction
+extract_devices(mos4("NMOS"), { "SD" => nsd, "G" => ngate, "W" => bulk, 
+                                "tS" => nsd, "tD" => nsd, "tG" => poly, "tW" => bulk })
+
+# Define connectivity for netlist extraction
+
+# Inter-layer
+connect(psd,        contact)
+connect(nsd,        contact)
+connect(poly,       contact)
+connect(ntie,       contact)
+connect(nwell,      ntie)
+connect(ptie,       contact)
+connect(contact,    metal1)
+connect(metal1,     via1)
+connect(via1,       metal2)
+
+# Global
+connect_global(bulk, "SUBSTRATE")
+connect_global(ptie, "SUBSTRATE")
+
+# Compare section
+
+netlist.simplify
+
+compare
+
+# issue-971
+compare
+
diff --git a/testdata/lvs/ringo_simple_compare2.lvsdb.1 b/testdata/lvs/ringo_simple_compare2.lvsdb.1
new file mode 100644
index 000000000..b4494918c
--- /dev/null
+++ b/testdata/lvs/ringo_simple_compare2.lvsdb.1
@@ -0,0 +1,908 @@
+#%lvsdb-klayout
+
+# Layout
+layout(
+ top(RINGO)
+ unit(0.001)
+
+ # Layer section
+ # This section lists the mask layers (drawing or derived) and their connections.
+
+ # Mask layers
+ layer(l3 '1/0')
+ layer(l4 '5/0')
+ layer(l8 '8/0')
+ layer(l11 '9/0')
+ layer(l12 '10/0')
+ layer(l13 '11/0')
+ layer(l7)
+ layer(l2)
+ layer(l9)
+ layer(l6)
+ layer(l10)
+
+ # Mask layer connectivity
+ connect(l3 l3 l9)
+ connect(l4 l4 l8)
+ connect(l8 l4 l8 l11 l2 l9 l6 l10)
+ connect(l11 l8 l11 l12)
+ connect(l12 l11 l12 l13)
+ connect(l13 l12 l13)
+ connect(l7 l7)
+ connect(l2 l8 l2)
+ connect(l9 l3 l8 l9)
+ connect(l6 l8 l6)
+ connect(l10 l8 l10)
+
+ # Global nets and connectivity
+ global(l7 SUBSTRATE)
+ global(l10 SUBSTRATE)
+
+ # Device class section
+ class(PMOS MOS4)
+ class(NMOS MOS4)
+
+ # Device abstracts section
+ # Device abstracts list the pin shapes of the devices.
+ device(D$PMOS PMOS
+  terminal(S
+   rect(l2 (-550 -750) (425 1500))
+  )
+  terminal(G
+   rect(l4 (-125 -750) (250 1500))
+  )
+  terminal(D
+   rect(l2 (125 -750) (450 1500))
+  )
+  terminal(B
+   rect(l3 (-125 -750) (250 1500))
+  )
+ )
+ device(D$PMOS$1 PMOS
+  terminal(S
+   rect(l2 (-575 -750) (450 1500))
+  )
+  terminal(G
+   rect(l4 (-125 -750) (250 1500))
+  )
+  terminal(D
+   rect(l2 (125 -750) (425 1500))
+  )
+  terminal(B
+   rect(l3 (-125 -750) (250 1500))
+  )
+ )
+ device(D$PMOS$2 PMOS
+  terminal(S
+   rect(l2 (-550 -750) (425 1500))
+  )
+  terminal(G
+   rect(l4 (-125 -750) (250 1500))
+  )
+  terminal(D
+   rect(l2 (125 -750) (425 1500))
+  )
+  terminal(B
+   rect(l3 (-125 -750) (250 1500))
+  )
+ )
+ device(D$NMOS NMOS
+  terminal(S
+   rect(l6 (-550 -475) (425 950))
+  )
+  terminal(G
+   rect(l4 (-125 -475) (250 950))
+  )
+  terminal(D
+   rect(l6 (125 -475) (450 950))
+  )
+  terminal(B
+   rect(l7 (-125 -475) (250 950))
+  )
+ )
+ device(D$NMOS$1 NMOS
+  terminal(S
+   rect(l6 (-575 -475) (450 950))
+  )
+  terminal(G
+   rect(l4 (-125 -475) (250 950))
+  )
+  terminal(D
+   rect(l6 (125 -475) (425 950))
+  )
+  terminal(B
+   rect(l7 (-125 -475) (250 950))
+  )
+ )
+ device(D$NMOS$2 NMOS
+  terminal(S
+   rect(l6 (-550 -475) (425 950))
+  )
+  terminal(G
+   rect(l4 (-125 -475) (250 950))
+  )
+  terminal(D
+   rect(l6 (125 -475) (425 950))
+  )
+  terminal(B
+   rect(l7 (-125 -475) (250 950))
+  )
+ )
+
+ # Circuit section
+ # Circuits are the hierarchical building blocks of the netlist.
+ circuit(ND2X1
+
+  # Circuit boundary
+  rect((-100 400) (2600 7600))
+
+  # Nets with their geometries
+  net(1 name(VDD)
+   rect(l8 (1110 5160) (180 180))
+   rect(l8 (-180 920) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l11 (-240 -790) (300 1700))
+   rect(l11 (-1350 0) (2400 800))
+   rect(l11 (-1151 -401) (2 2))
+   rect(l2 (-276 -2151) (425 1500))
+   rect(l2 (-400 -1500) (425 1500))
+  )
+  net(2 name(OUT)
+   rect(l8 (1810 1770) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (-1580 3760) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (1220 920) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (-180 370) (180 180))
+   polygon(l11 (-240 -4180) (0 1390) (490 0) (0 -300) (-190 0) (0 -1090))
+   rect(l11 (-110 1390) (300 1400))
+   polygon(l11 (-1890 0) (0 600) (300 0) (0 -300) (1590 0) (0 -300))
+   rect(l11 (-141 -501) (2 2))
+   rect(l11 (-1751 1099) (300 1400))
+   rect(l11 (1100 -1700) (300 300))
+   rect(l11 (-300 0) (300 1400))
+   rect(l2 (-1750 -1450) (425 1500))
+   rect(l2 (950 -1500) (425 1500))
+   rect(l6 (-425 -4890) (425 950))
+  )
+  net(3 name(VSS)
+   rect(l8 (410 1770) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-240 -1300) (300 1360))
+   rect(l11 (-650 -2160) (2400 800))
+   rect(l11 (-1151 -401) (2 2))
+   rect(l6 (-951 859) (425 950))
+  )
+  net(4
+   rect(l3 (-100 4500) (2600 3500))
+  )
+  net(5 name(B)
+   rect(l4 (1425 2860) (250 1940))
+   rect(l4 (-345 -950) (300 300))
+   rect(l4 (-205 650) (250 2000))
+   rect(l4 (-250 -2000) (250 2000))
+   rect(l4 (-250 -5390) (250 1450))
+   rect(l8 (-285 1050) (180 180))
+   rect(l11 (-71 -91) (2 2))
+   rect(l11 (-171 -151) (300 300))
+  )
+  net(6 name(A)
+   rect(l4 (725 2860) (250 1940))
+   rect(l4 (-325 -1850) (300 300))
+   rect(l4 (-225 1550) (250 2000))
+   rect(l4 (-250 -2000) (250 2000))
+   rect(l4 (-250 -5390) (250 1450))
+   rect(l8 (-265 150) (180 180))
+   rect(l11 (-91 -91) (2 2))
+   rect(l11 (-151 -151) (300 300))
+  )
+  net(7 name(SUBSTRATE))
+  net(8
+   rect(l6 (975 1660) (425 950))
+   rect(l6 (-400 -950) (425 950))
+  )
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4)
+  pin(5 name(B))
+  pin(6 name(A))
+  pin(7 name(SUBSTRATE))
+
+  # Devices and their connections
+  device(1 D$PMOS
+   location(850 5800)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0.6375)
+   param(AD 0.3375)
+   param(PS 3.85)
+   param(PD 1.95)
+   terminal(S 2)
+   terminal(G 6)
+   terminal(D 1)
+   terminal(B 4)
+  )
+  device(2 D$PMOS$1
+   location(1550 5800)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0.3375)
+   param(AD 0.6375)
+   param(PS 1.95)
+   param(PD 3.85)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(3 D$NMOS
+   location(850 2135)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0.40375)
+   param(AD 0.21375)
+   param(PS 2.75)
+   param(PD 1.4)
+   terminal(S 3)
+   terminal(G 6)
+   terminal(D 8)
+   terminal(B 7)
+  )
+  device(4 D$NMOS$1
+   location(1550 2135)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0.21375)
+   param(AD 0.40375)
+   param(PS 1.4)
+   param(PD 2.75)
+   terminal(S 8)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 7)
+  )
+
+ )
+ circuit(INVX1
+
+  # Circuit boundary
+  rect((-100 400) (2000 7600))
+
+  # Nets with their geometries
+  net(1 name(VDD)
+   rect(l8 (410 6260) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l11 (-240 -240) (300 1400))
+   rect(l11 (-650 300) (1800 800))
+   rect(l11 (-1450 -1100) (300 300))
+   rect(l11 (299 399) (2 2))
+   rect(l2 (-651 -2151) (425 1500))
+  )
+  net(2 name(OUT)
+   rect(l8 (1110 5160) (180 180))
+   rect(l8 (-180 920) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (-180 -4120) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-240 -790) (300 4790))
+   rect(l11 (-151 -2501) (2 2))
+   rect(l2 (-226 1049) (425 1500))
+   rect(l6 (-425 -4890) (425 950))
+  )
+  net(3 name(VSS)
+   rect(l8 (410 1770) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-240 -1300) (300 1360))
+   rect(l11 (-650 -2160) (1800 800))
+   rect(l11 (-851 -401) (2 2))
+   rect(l6 (-651 859) (425 950))
+  )
+  net(4
+   rect(l3 (-100 4500) (2000 3500))
+  )
+  net(5 name(IN)
+   rect(l4 (725 2860) (250 1940))
+   rect(l4 (-525 -1850) (300 300))
+   rect(l4 (-25 1550) (250 2000))
+   rect(l4 (-250 -2000) (250 2000))
+   rect(l4 (-250 -5390) (250 1450))
+   rect(l8 (-465 150) (180 180))
+   rect(l11 (-91 -91) (2 2))
+   rect(l11 (-151 -151) (300 300))
+  )
+  net(6 name(SUBSTRATE))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4)
+  pin(5 name(IN))
+  pin(6 name(SUBSTRATE))
+
+  # Devices and their connections
+  device(1 D$PMOS$2
+   location(850 5800)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0.6375)
+   param(AD 0.6375)
+   param(PS 3.85)
+   param(PD 3.85)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(2 D$NMOS$2
+   location(850 2135)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0.40375)
+   param(AD 0.40375)
+   param(PS 2.75)
+   param(PD 2.75)
+   terminal(S 3)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 6)
+  )
+
+ )
+ circuit(RINGO
+
+  # Circuit boundary
+  rect((0 350) (25800 7650))
+
+  # Nets with their geometries
+  net(1
+   rect(l11 (4040 2950) (610 300))
+  )
+  net(2
+   rect(l11 (5550 2950) (900 300))
+  )
+  net(3
+   rect(l11 (7350 2950) (900 300))
+  )
+  net(4
+   rect(l11 (9150 2950) (900 300))
+  )
+  net(5
+   rect(l11 (10950 2950) (900 300))
+  )
+  net(6
+   rect(l11 (12750 2950) (900 300))
+  )
+  net(7
+   rect(l11 (14550 2950) (900 300))
+  )
+  net(8
+   rect(l11 (16350 2950) (900 300))
+  )
+  net(9
+   rect(l11 (18150 2950) (900 300))
+  )
+  net(10
+   rect(l11 (19950 2950) (900 300))
+  )
+  net(11 name(FB)
+   rect(l11 (21750 2950) (900 300))
+   rect(l11 (-19530 590) (320 320))
+   rect(l11 (17820 -320) (320 320))
+   rect(l12 (-18400 -260) (200 200))
+   rect(l12 (17940 -200) (200 200))
+   rect(l13 (-18040 -300) (17740 400))
+   rect(l13 (-17921 -201) (2 2))
+   rect(l13 (-221 -201) (400 400))
+   rect(l13 (17740 -400) (400 400))
+  )
+  net(12 name(VDD)
+   rect(l3 (500 4500) (1400 3500))
+   rect(l3 (-1900 -3500) (600 3500))
+   rect(l3 (23300 -3500) (1400 3500))
+   rect(l3 (-100 -3500) (600 3500))
+   rect(l8 (-24690 -1240) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (23220 370) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l11 (-21741 859) (2 2))
+   rect(l11 (-2351 -451) (1200 800))
+   rect(l11 (-750 -1450) (300 1400))
+   rect(l11 (-101 -351) (2 2))
+   rect(l11 (-1251 -401) (600 800))
+   rect(l11 (23400 -800) (1200 800))
+   rect(l11 (-750 -1450) (300 1400))
+   rect(l11 (-101 -351) (2 2))
+   rect(l11 (549 -401) (600 800))
+   rect(l9 (-24850 -1500) (500 1500))
+   rect(l9 (22900 -1500) (500 1500))
+  )
+  net(13 name(OUT)
+   rect(l11 (23440 3840) (320 320))
+   rect(l12 (-260 -260) (200 200))
+   rect(l13 (-101 -101) (2 2))
+   rect(l13 (-201 -201) (400 400))
+  )
+  net(14 name(ENABLE)
+   rect(l11 (2440 2940) (320 320))
+   rect(l12 (-260 -260) (200 200))
+   rect(l13 (-101 -101) (2 2))
+   rect(l13 (-201 -201) (400 400))
+  )
+  net(15 name(VSS)
+   rect(l8 (1110 1610) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (23220 370) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-21741 -391) (2 2))
+   rect(l11 (-1901 -401) (300 1400))
+   rect(l11 (-750 -1450) (1200 800))
+   rect(l11 (-551 -401) (2 2))
+   rect(l11 (-1251 -401) (600 800))
+   rect(l11 (23850 -750) (300 1400))
+   rect(l11 (-750 -1450) (1200 800))
+   rect(l11 (-551 -401) (2 2))
+   rect(l11 (549 -401) (600 800))
+   rect(l10 (-24850 -800) (500 1500))
+   rect(l10 (22900 -1500) (500 1500))
+  )
+
+  # Outgoing pins and their connections to nets
+  pin(11 name(FB))
+  pin(12 name(VDD))
+  pin(13 name(OUT))
+  pin(14 name(ENABLE))
+  pin(15 name(VSS))
+
+  # Subcircuits and their connections
+  circuit(1 ND2X1 location(1800 0)
+   pin(0 12)
+   pin(1 1)
+   pin(2 15)
+   pin(3 12)
+   pin(4 11)
+   pin(5 14)
+   pin(6 15)
+  )
+  circuit(2 INVX1 location(4200 0)
+   pin(0 12)
+   pin(1 2)
+   pin(2 15)
+   pin(3 12)
+   pin(4 1)
+   pin(5 15)
+  )
+  circuit(3 INVX1 location(6000 0)
+   pin(0 12)
+   pin(1 3)
+   pin(2 15)
+   pin(3 12)
+   pin(4 2)
+   pin(5 15)
+  )
+  circuit(4 INVX1 location(7800 0)
+   pin(0 12)
+   pin(1 4)
+   pin(2 15)
+   pin(3 12)
+   pin(4 3)
+   pin(5 15)
+  )
+  circuit(5 INVX1 location(9600 0)
+   pin(0 12)
+   pin(1 5)
+   pin(2 15)
+   pin(3 12)
+   pin(4 4)
+   pin(5 15)
+  )
+  circuit(6 INVX1 location(11400 0)
+   pin(0 12)
+   pin(1 6)
+   pin(2 15)
+   pin(3 12)
+   pin(4 5)
+   pin(5 15)
+  )
+  circuit(7 INVX1 location(13200 0)
+   pin(0 12)
+   pin(1 7)
+   pin(2 15)
+   pin(3 12)
+   pin(4 6)
+   pin(5 15)
+  )
+  circuit(8 INVX1 location(15000 0)
+   pin(0 12)
+   pin(1 8)
+   pin(2 15)
+   pin(3 12)
+   pin(4 7)
+   pin(5 15)
+  )
+  circuit(9 INVX1 location(16800 0)
+   pin(0 12)
+   pin(1 9)
+   pin(2 15)
+   pin(3 12)
+   pin(4 8)
+   pin(5 15)
+  )
+  circuit(10 INVX1 location(18600 0)
+   pin(0 12)
+   pin(1 10)
+   pin(2 15)
+   pin(3 12)
+   pin(4 9)
+   pin(5 15)
+  )
+  circuit(11 INVX1 location(20400 0)
+   pin(0 12)
+   pin(1 11)
+   pin(2 15)
+   pin(3 12)
+   pin(4 10)
+   pin(5 15)
+  )
+  circuit(12 INVX1 location(22200 0)
+   pin(0 12)
+   pin(1 13)
+   pin(2 15)
+   pin(3 12)
+   pin(4 11)
+   pin(5 15)
+  )
+
+ )
+)
+
+# Reference netlist
+reference(
+
+ # Device class section
+ class(PMOS MOS4)
+ class(NMOS MOS4)
+
+ # Circuit section
+ # Circuits are the hierarchical building blocks of the netlist.
+ circuit(ND2X1
+
+  # Nets
+  net(1 name(VDD))
+  net(2 name(OUT))
+  net(3 name(VSS))
+  net(4 name(NWELL))
+  net(5 name(B))
+  net(6 name(A))
+  net(7 name(BULK))
+  net(8 name('1'))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4 name(NWELL))
+  pin(5 name(B))
+  pin(6 name(A))
+  pin(7 name(BULK))
+
+  # Devices and their connections
+  device(1 PMOS
+   name($1)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 2)
+   terminal(G 6)
+   terminal(D 1)
+   terminal(B 4)
+  )
+  device(2 PMOS
+   name($2)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(3 NMOS
+   name($3)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 3)
+   terminal(G 6)
+   terminal(D 8)
+   terminal(B 7)
+  )
+  device(4 NMOS
+   name($4)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 8)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 7)
+  )
+
+ )
+ circuit(INVX1
+
+  # Nets
+  net(1 name(VDD))
+  net(2 name(OUT))
+  net(3 name(VSS))
+  net(4 name(NWELL))
+  net(5 name(IN))
+  net(6 name(BULK))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4 name(NWELL))
+  pin(5 name(IN))
+  pin(6 name(BULK))
+
+  # Devices and their connections
+  device(1 PMOS
+   name($1)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(2 NMOS
+   name($2)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 3)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 6)
+  )
+
+ )
+ circuit(RINGO
+
+  # Nets
+  net(1 name(VSS))
+  net(2 name(VDD))
+  net(3 name(FB))
+  net(4 name(ENABLE))
+  net(5 name(OUT))
+  net(6 name('1'))
+  net(7 name('2'))
+  net(8 name('3'))
+  net(9 name('4'))
+  net(10 name('5'))
+  net(11 name('6'))
+  net(12 name('7'))
+  net(13 name('8'))
+  net(14 name('9'))
+  net(15 name('10'))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VSS))
+  pin(2 name(VDD))
+  pin(3 name(FB))
+  pin(4 name(ENABLE))
+  pin(5 name(OUT))
+
+  # Subcircuits and their connections
+  circuit(1 ND2X1 name($1)
+   pin(0 2)
+   pin(1 6)
+   pin(2 1)
+   pin(3 2)
+   pin(4 3)
+   pin(5 4)
+   pin(6 1)
+  )
+  circuit(2 INVX1 name($2)
+   pin(0 2)
+   pin(1 7)
+   pin(2 1)
+   pin(3 2)
+   pin(4 6)
+   pin(5 1)
+  )
+  circuit(3 INVX1 name($3)
+   pin(0 2)
+   pin(1 8)
+   pin(2 1)
+   pin(3 2)
+   pin(4 7)
+   pin(5 1)
+  )
+  circuit(4 INVX1 name($4)
+   pin(0 2)
+   pin(1 9)
+   pin(2 1)
+   pin(3 2)
+   pin(4 8)
+   pin(5 1)
+  )
+  circuit(5 INVX1 name($5)
+   pin(0 2)
+   pin(1 10)
+   pin(2 1)
+   pin(3 2)
+   pin(4 9)
+   pin(5 1)
+  )
+  circuit(6 INVX1 name($6)
+   pin(0 2)
+   pin(1 11)
+   pin(2 1)
+   pin(3 2)
+   pin(4 10)
+   pin(5 1)
+  )
+  circuit(7 INVX1 name($7)
+   pin(0 2)
+   pin(1 12)
+   pin(2 1)
+   pin(3 2)
+   pin(4 11)
+   pin(5 1)
+  )
+  circuit(8 INVX1 name($8)
+   pin(0 2)
+   pin(1 13)
+   pin(2 1)
+   pin(3 2)
+   pin(4 12)
+   pin(5 1)
+  )
+  circuit(9 INVX1 name($9)
+   pin(0 2)
+   pin(1 14)
+   pin(2 1)
+   pin(3 2)
+   pin(4 13)
+   pin(5 1)
+  )
+  circuit(10 INVX1 name($10)
+   pin(0 2)
+   pin(1 15)
+   pin(2 1)
+   pin(3 2)
+   pin(4 14)
+   pin(5 1)
+  )
+  circuit(11 INVX1 name($11)
+   pin(0 2)
+   pin(1 3)
+   pin(2 1)
+   pin(3 2)
+   pin(4 15)
+   pin(5 1)
+  )
+  circuit(12 INVX1 name($12)
+   pin(0 2)
+   pin(1 5)
+   pin(2 1)
+   pin(3 2)
+   pin(4 3)
+   pin(5 1)
+  )
+
+ )
+)
+
+# Cross reference
+xref(
+ circuit(INVX1 INVX1 match
+  xref(
+   net(4 4 match)
+   net(5 5 match)
+   net(2 2 match)
+   net(6 6 match)
+   net(1 1 match)
+   net(3 3 match)
+   pin(3 3 match)
+   pin(4 4 match)
+   pin(1 1 match)
+   pin(5 5 match)
+   pin(0 0 match)
+   pin(2 2 match)
+   device(2 2 match)
+   device(1 1 match)
+  )
+ )
+ circuit(ND2X1 ND2X1 match
+  xref(
+   net(8 8 match)
+   net(4 4 match)
+   net(6 6 match)
+   net(5 5 match)
+   net(2 2 match)
+   net(7 7 match)
+   net(1 1 match)
+   net(3 3 match)
+   pin(3 3 match)
+   pin(5 5 match)
+   pin(4 4 match)
+   pin(1 1 match)
+   pin(6 6 match)
+   pin(0 0 match)
+   pin(2 2 match)
+   device(3 3 match)
+   device(4 4 match)
+   device(1 1 match)
+   device(2 2 match)
+  )
+ )
+ circuit(RINGO RINGO match
+  xref(
+   net(1 6 match)
+   net(10 15 match)
+   net(2 7 match)
+   net(3 8 match)
+   net(4 9 match)
+   net(5 10 match)
+   net(6 11 match)
+   net(7 12 match)
+   net(8 13 match)
+   net(9 14 match)
+   net(14 4 match)
+   net(11 3 match)
+   net(13 5 match)
+   net(12 2 match)
+   net(15 1 match)
+   pin(3 3 match)
+   pin(0 2 match)
+   pin(2 4 match)
+   pin(1 1 match)
+   pin(4 0 match)
+   circuit(2 2 match)
+   circuit(3 3 match)
+   circuit(4 4 match)
+   circuit(5 5 match)
+   circuit(6 6 match)
+   circuit(7 7 match)
+   circuit(8 8 match)
+   circuit(9 9 match)
+   circuit(10 10 match)
+   circuit(11 11 match)
+   circuit(12 12 match)
+   circuit(1 1 match)
+  )
+ )
+)
diff --git a/testdata/lvs/ringo_simple_compare2.lvsdb.2 b/testdata/lvs/ringo_simple_compare2.lvsdb.2
new file mode 100644
index 000000000..b585c4ca4
--- /dev/null
+++ b/testdata/lvs/ringo_simple_compare2.lvsdb.2
@@ -0,0 +1,908 @@
+#%lvsdb-klayout
+
+# Layout
+layout(
+ top(RINGO)
+ unit(0.001)
+
+ # Layer section
+ # This section lists the mask layers (drawing or derived) and their connections.
+
+ # Mask layers
+ layer(l3 '1/0')
+ layer(l4 '5/0')
+ layer(l8 '8/0')
+ layer(l11 '9/0')
+ layer(l12 '10/0')
+ layer(l13 '11/0')
+ layer(l7)
+ layer(l2)
+ layer(l9)
+ layer(l6)
+ layer(l10)
+
+ # Mask layer connectivity
+ connect(l3 l3 l9)
+ connect(l4 l4 l8)
+ connect(l8 l4 l8 l11 l2 l9 l6 l10)
+ connect(l11 l8 l11 l12)
+ connect(l12 l11 l12 l13)
+ connect(l13 l12 l13)
+ connect(l7 l7)
+ connect(l2 l8 l2)
+ connect(l9 l3 l8 l9)
+ connect(l6 l8 l6)
+ connect(l10 l8 l10)
+
+ # Global nets and connectivity
+ global(l7 SUBSTRATE)
+ global(l10 SUBSTRATE)
+
+ # Device class section
+ class(PMOS MOS4)
+ class(NMOS MOS4)
+
+ # Device abstracts section
+ # Device abstracts list the pin shapes of the devices.
+ device(D$PMOS PMOS
+  terminal(S
+   rect(l2 (-550 -750) (425 1500))
+  )
+  terminal(G
+   rect(l4 (-125 -750) (250 1500))
+  )
+  terminal(D
+   rect(l2 (125 -750) (450 1500))
+  )
+  terminal(B
+   rect(l3 (-125 -750) (250 1500))
+  )
+ )
+ device(D$PMOS$1 PMOS
+  terminal(S
+   rect(l2 (-575 -750) (450 1500))
+  )
+  terminal(G
+   rect(l4 (-125 -750) (250 1500))
+  )
+  terminal(D
+   rect(l2 (125 -750) (425 1500))
+  )
+  terminal(B
+   rect(l3 (-125 -750) (250 1500))
+  )
+ )
+ device(D$PMOS$2 PMOS
+  terminal(S
+   rect(l2 (-550 -750) (425 1500))
+  )
+  terminal(G
+   rect(l4 (-125 -750) (250 1500))
+  )
+  terminal(D
+   rect(l2 (125 -750) (425 1500))
+  )
+  terminal(B
+   rect(l3 (-125 -750) (250 1500))
+  )
+ )
+ device(D$NMOS NMOS
+  terminal(S
+   rect(l6 (-550 -475) (425 950))
+  )
+  terminal(G
+   rect(l4 (-125 -475) (250 950))
+  )
+  terminal(D
+   rect(l6 (125 -475) (450 950))
+  )
+  terminal(B
+   rect(l7 (-125 -475) (250 950))
+  )
+ )
+ device(D$NMOS$1 NMOS
+  terminal(S
+   rect(l6 (-575 -475) (450 950))
+  )
+  terminal(G
+   rect(l4 (-125 -475) (250 950))
+  )
+  terminal(D
+   rect(l6 (125 -475) (425 950))
+  )
+  terminal(B
+   rect(l7 (-125 -475) (250 950))
+  )
+ )
+ device(D$NMOS$2 NMOS
+  terminal(S
+   rect(l6 (-550 -475) (425 950))
+  )
+  terminal(G
+   rect(l4 (-125 -475) (250 950))
+  )
+  terminal(D
+   rect(l6 (125 -475) (425 950))
+  )
+  terminal(B
+   rect(l7 (-125 -475) (250 950))
+  )
+ )
+
+ # Circuit section
+ # Circuits are the hierarchical building blocks of the netlist.
+ circuit(ND2X1
+
+  # Circuit boundary
+  rect((-100 400) (2600 7600))
+
+  # Nets with their geometries
+  net(1 name(VDD)
+   rect(l8 (1110 5160) (180 180))
+   rect(l8 (-180 920) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l11 (-240 -790) (300 1700))
+   rect(l11 (-1350 0) (2400 800))
+   rect(l11 (-1151 -401) (2 2))
+   rect(l2 (-276 -2151) (425 1500))
+   rect(l2 (-400 -1500) (425 1500))
+  )
+  net(2 name(OUT)
+   rect(l8 (1810 1770) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (-1580 3760) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (1220 920) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (-180 370) (180 180))
+   polygon(l11 (-240 -4180) (0 1390) (490 0) (0 -300) (-190 0) (0 -1090))
+   rect(l11 (-110 1390) (300 1400))
+   polygon(l11 (-1890 0) (0 600) (300 0) (0 -300) (1590 0) (0 -300))
+   rect(l11 (-141 -501) (2 2))
+   rect(l11 (-1751 1099) (300 1400))
+   rect(l11 (1100 -1700) (300 300))
+   rect(l11 (-300 0) (300 1400))
+   rect(l2 (-375 -1450) (425 1500))
+   rect(l2 (-1800 -1500) (425 1500))
+   rect(l6 (950 -4890) (425 950))
+  )
+  net(3 name(VSS)
+   rect(l8 (410 1770) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-240 -1300) (300 1360))
+   rect(l11 (-650 -2160) (2400 800))
+   rect(l11 (-1151 -401) (2 2))
+   rect(l6 (-951 859) (425 950))
+  )
+  net(4
+   rect(l3 (-100 4500) (2600 3500))
+  )
+  net(5 name(B)
+   rect(l4 (1425 2860) (250 1940))
+   rect(l4 (-345 -950) (300 300))
+   rect(l4 (-205 650) (250 2000))
+   rect(l4 (-250 -2000) (250 2000))
+   rect(l4 (-250 -5390) (250 1450))
+   rect(l8 (-285 1050) (180 180))
+   rect(l11 (-71 -91) (2 2))
+   rect(l11 (-171 -151) (300 300))
+  )
+  net(6 name(A)
+   rect(l4 (725 2860) (250 1940))
+   rect(l4 (-325 -1850) (300 300))
+   rect(l4 (-225 1550) (250 2000))
+   rect(l4 (-250 -2000) (250 2000))
+   rect(l4 (-250 -5390) (250 1450))
+   rect(l8 (-265 150) (180 180))
+   rect(l11 (-91 -91) (2 2))
+   rect(l11 (-151 -151) (300 300))
+  )
+  net(7 name(SUBSTRATE))
+  net(8
+   rect(l6 (975 1660) (425 950))
+   rect(l6 (-400 -950) (425 950))
+  )
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4)
+  pin(5 name(B))
+  pin(6 name(A))
+  pin(7 name(SUBSTRATE))
+
+  # Devices and their connections
+  device(1 D$PMOS
+   location(850 5800)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0.6375)
+   param(AD 0.3375)
+   param(PS 3.85)
+   param(PD 1.95)
+   terminal(S 2)
+   terminal(G 6)
+   terminal(D 1)
+   terminal(B 4)
+  )
+  device(2 D$PMOS$1
+   location(1550 5800)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0.3375)
+   param(AD 0.6375)
+   param(PS 1.95)
+   param(PD 3.85)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(3 D$NMOS
+   location(850 2135)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0.40375)
+   param(AD 0.21375)
+   param(PS 2.75)
+   param(PD 1.4)
+   terminal(S 3)
+   terminal(G 6)
+   terminal(D 8)
+   terminal(B 7)
+  )
+  device(4 D$NMOS$1
+   location(1550 2135)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0.21375)
+   param(AD 0.40375)
+   param(PS 1.4)
+   param(PD 2.75)
+   terminal(S 8)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 7)
+  )
+
+ )
+ circuit(INVX1
+
+  # Circuit boundary
+  rect((-100 400) (2000 7600))
+
+  # Nets with their geometries
+  net(1 name(VDD)
+   rect(l8 (410 6260) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l11 (-240 -240) (300 1400))
+   rect(l11 (-650 300) (1800 800))
+   rect(l11 (-1450 -1100) (300 300))
+   rect(l11 (299 399) (2 2))
+   rect(l2 (-651 -2151) (425 1500))
+  )
+  net(2 name(OUT)
+   rect(l8 (1110 5160) (180 180))
+   rect(l8 (-180 920) (180 180))
+   rect(l8 (-180 -730) (180 180))
+   rect(l8 (-180 -4120) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-240 -790) (300 4790))
+   rect(l11 (-151 -2501) (2 2))
+   rect(l2 (-226 1049) (425 1500))
+   rect(l6 (-425 -4890) (425 950))
+  )
+  net(3 name(VSS)
+   rect(l8 (410 1770) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-240 -1300) (300 1360))
+   rect(l11 (-650 -2160) (1800 800))
+   rect(l11 (-851 -401) (2 2))
+   rect(l6 (-651 859) (425 950))
+  )
+  net(4
+   rect(l3 (-100 4500) (2000 3500))
+  )
+  net(5 name(IN)
+   rect(l4 (725 2860) (250 1940))
+   rect(l4 (-525 -1850) (300 300))
+   rect(l4 (-25 1550) (250 2000))
+   rect(l4 (-250 -2000) (250 2000))
+   rect(l4 (-250 -5390) (250 1450))
+   rect(l8 (-465 150) (180 180))
+   rect(l11 (-91 -91) (2 2))
+   rect(l11 (-151 -151) (300 300))
+  )
+  net(6 name(SUBSTRATE))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4)
+  pin(5 name(IN))
+  pin(6 name(SUBSTRATE))
+
+  # Devices and their connections
+  device(1 D$PMOS$2
+   location(850 5800)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0.6375)
+   param(AD 0.6375)
+   param(PS 3.85)
+   param(PD 3.85)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(2 D$NMOS$2
+   location(850 2135)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0.40375)
+   param(AD 0.40375)
+   param(PS 2.75)
+   param(PD 2.75)
+   terminal(S 3)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 6)
+  )
+
+ )
+ circuit(RINGO
+
+  # Circuit boundary
+  rect((0 350) (25800 7650))
+
+  # Nets with their geometries
+  net(1
+   rect(l11 (4040 2950) (610 300))
+  )
+  net(2
+   rect(l11 (5550 2950) (900 300))
+  )
+  net(3
+   rect(l11 (7350 2950) (900 300))
+  )
+  net(4
+   rect(l11 (9150 2950) (900 300))
+  )
+  net(5
+   rect(l11 (10950 2950) (900 300))
+  )
+  net(6
+   rect(l11 (12750 2950) (900 300))
+  )
+  net(7
+   rect(l11 (14550 2950) (900 300))
+  )
+  net(8
+   rect(l11 (16350 2950) (900 300))
+  )
+  net(9
+   rect(l11 (18150 2950) (900 300))
+  )
+  net(10
+   rect(l11 (19950 2950) (900 300))
+  )
+  net(11 name(FB)
+   rect(l11 (21750 2950) (900 300))
+   rect(l11 (-19530 590) (320 320))
+   rect(l11 (17820 -320) (320 320))
+   rect(l12 (-18400 -260) (200 200))
+   rect(l12 (17940 -200) (200 200))
+   rect(l13 (-18040 -300) (17740 400))
+   rect(l13 (-17921 -201) (2 2))
+   rect(l13 (-221 -201) (400 400))
+   rect(l13 (17740 -400) (400 400))
+  )
+  net(12 name(VDD)
+   rect(l3 (500 4500) (1400 3500))
+   rect(l3 (-1900 -3500) (600 3500))
+   rect(l3 (23300 -3500) (1400 3500))
+   rect(l3 (-100 -3500) (600 3500))
+   rect(l8 (-24690 -1240) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (23220 370) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l11 (-21741 859) (2 2))
+   rect(l11 (-2351 -451) (1200 800))
+   rect(l11 (-750 -1450) (300 1400))
+   rect(l11 (-101 -351) (2 2))
+   rect(l11 (-1251 -401) (600 800))
+   rect(l11 (23400 -800) (1200 800))
+   rect(l11 (-750 -1450) (300 1400))
+   rect(l11 (-101 -351) (2 2))
+   rect(l11 (549 -401) (600 800))
+   rect(l9 (-24850 -1500) (500 1500))
+   rect(l9 (22900 -1500) (500 1500))
+  )
+  net(13 name(OUT)
+   rect(l11 (23440 3840) (320 320))
+   rect(l12 (-260 -260) (200 200))
+   rect(l13 (-101 -101) (2 2))
+   rect(l13 (-201 -201) (400 400))
+  )
+  net(14 name(ENABLE)
+   rect(l11 (2440 2940) (320 320))
+   rect(l12 (-260 -260) (200 200))
+   rect(l13 (-101 -101) (2 2))
+   rect(l13 (-201 -201) (400 400))
+  )
+  net(15 name(VSS)
+   rect(l8 (1110 1610) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l8 (23220 370) (180 180))
+   rect(l8 (-180 -1280) (180 180))
+   rect(l8 (-180 370) (180 180))
+   rect(l11 (-21741 -391) (2 2))
+   rect(l11 (-1901 -401) (300 1400))
+   rect(l11 (-750 -1450) (1200 800))
+   rect(l11 (-551 -401) (2 2))
+   rect(l11 (-1251 -401) (600 800))
+   rect(l11 (23850 -750) (300 1400))
+   rect(l11 (-750 -1450) (1200 800))
+   rect(l11 (-551 -401) (2 2))
+   rect(l11 (549 -401) (600 800))
+   rect(l10 (-24850 -800) (500 1500))
+   rect(l10 (22900 -1500) (500 1500))
+  )
+
+  # Outgoing pins and their connections to nets
+  pin(11 name(FB))
+  pin(12 name(VDD))
+  pin(13 name(OUT))
+  pin(14 name(ENABLE))
+  pin(15 name(VSS))
+
+  # Subcircuits and their connections
+  circuit(1 ND2X1 location(1800 0)
+   pin(0 12)
+   pin(1 1)
+   pin(2 15)
+   pin(3 12)
+   pin(4 11)
+   pin(5 14)
+   pin(6 15)
+  )
+  circuit(2 INVX1 location(4200 0)
+   pin(0 12)
+   pin(1 2)
+   pin(2 15)
+   pin(3 12)
+   pin(4 1)
+   pin(5 15)
+  )
+  circuit(3 INVX1 location(6000 0)
+   pin(0 12)
+   pin(1 3)
+   pin(2 15)
+   pin(3 12)
+   pin(4 2)
+   pin(5 15)
+  )
+  circuit(4 INVX1 location(7800 0)
+   pin(0 12)
+   pin(1 4)
+   pin(2 15)
+   pin(3 12)
+   pin(4 3)
+   pin(5 15)
+  )
+  circuit(5 INVX1 location(9600 0)
+   pin(0 12)
+   pin(1 5)
+   pin(2 15)
+   pin(3 12)
+   pin(4 4)
+   pin(5 15)
+  )
+  circuit(6 INVX1 location(11400 0)
+   pin(0 12)
+   pin(1 6)
+   pin(2 15)
+   pin(3 12)
+   pin(4 5)
+   pin(5 15)
+  )
+  circuit(7 INVX1 location(13200 0)
+   pin(0 12)
+   pin(1 7)
+   pin(2 15)
+   pin(3 12)
+   pin(4 6)
+   pin(5 15)
+  )
+  circuit(8 INVX1 location(15000 0)
+   pin(0 12)
+   pin(1 8)
+   pin(2 15)
+   pin(3 12)
+   pin(4 7)
+   pin(5 15)
+  )
+  circuit(9 INVX1 location(16800 0)
+   pin(0 12)
+   pin(1 9)
+   pin(2 15)
+   pin(3 12)
+   pin(4 8)
+   pin(5 15)
+  )
+  circuit(10 INVX1 location(18600 0)
+   pin(0 12)
+   pin(1 10)
+   pin(2 15)
+   pin(3 12)
+   pin(4 9)
+   pin(5 15)
+  )
+  circuit(11 INVX1 location(20400 0)
+   pin(0 12)
+   pin(1 11)
+   pin(2 15)
+   pin(3 12)
+   pin(4 10)
+   pin(5 15)
+  )
+  circuit(12 INVX1 location(22200 0)
+   pin(0 12)
+   pin(1 13)
+   pin(2 15)
+   pin(3 12)
+   pin(4 11)
+   pin(5 15)
+  )
+
+ )
+)
+
+# Reference netlist
+reference(
+
+ # Device class section
+ class(PMOS MOS4)
+ class(NMOS MOS4)
+
+ # Circuit section
+ # Circuits are the hierarchical building blocks of the netlist.
+ circuit(ND2X1
+
+  # Nets
+  net(1 name(VDD))
+  net(2 name(OUT))
+  net(3 name(VSS))
+  net(4 name(NWELL))
+  net(5 name(B))
+  net(6 name(A))
+  net(7 name(BULK))
+  net(8 name('1'))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4 name(NWELL))
+  pin(5 name(B))
+  pin(6 name(A))
+  pin(7 name(BULK))
+
+  # Devices and their connections
+  device(1 PMOS
+   name($1)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 2)
+   terminal(G 6)
+   terminal(D 1)
+   terminal(B 4)
+  )
+  device(2 PMOS
+   name($2)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(3 NMOS
+   name($3)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 3)
+   terminal(G 6)
+   terminal(D 8)
+   terminal(B 7)
+  )
+  device(4 NMOS
+   name($4)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 8)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 7)
+  )
+
+ )
+ circuit(INVX1
+
+  # Nets
+  net(1 name(VDD))
+  net(2 name(OUT))
+  net(3 name(VSS))
+  net(4 name(NWELL))
+  net(5 name(IN))
+  net(6 name(BULK))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VDD))
+  pin(2 name(OUT))
+  pin(3 name(VSS))
+  pin(4 name(NWELL))
+  pin(5 name(IN))
+  pin(6 name(BULK))
+
+  # Devices and their connections
+  device(1 PMOS
+   name($1)
+   param(L 0.25)
+   param(W 1.5)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 1)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 4)
+  )
+  device(2 NMOS
+   name($2)
+   param(L 0.25)
+   param(W 0.95)
+   param(AS 0)
+   param(AD 0)
+   param(PS 0)
+   param(PD 0)
+   terminal(S 3)
+   terminal(G 5)
+   terminal(D 2)
+   terminal(B 6)
+  )
+
+ )
+ circuit(RINGO
+
+  # Nets
+  net(1 name(VSS))
+  net(2 name(VDD))
+  net(3 name(FB))
+  net(4 name(ENABLE))
+  net(5 name(OUT))
+  net(6 name('1'))
+  net(7 name('2'))
+  net(8 name('3'))
+  net(9 name('4'))
+  net(10 name('5'))
+  net(11 name('6'))
+  net(12 name('7'))
+  net(13 name('8'))
+  net(14 name('9'))
+  net(15 name('10'))
+
+  # Outgoing pins and their connections to nets
+  pin(1 name(VSS))
+  pin(2 name(VDD))
+  pin(3 name(FB))
+  pin(4 name(ENABLE))
+  pin(5 name(OUT))
+
+  # Subcircuits and their connections
+  circuit(1 ND2X1 name($1)
+   pin(0 2)
+   pin(1 6)
+   pin(2 1)
+   pin(3 2)
+   pin(4 3)
+   pin(5 4)
+   pin(6 1)
+  )
+  circuit(2 INVX1 name($2)
+   pin(0 2)
+   pin(1 7)
+   pin(2 1)
+   pin(3 2)
+   pin(4 6)
+   pin(5 1)
+  )
+  circuit(3 INVX1 name($3)
+   pin(0 2)
+   pin(1 8)
+   pin(2 1)
+   pin(3 2)
+   pin(4 7)
+   pin(5 1)
+  )
+  circuit(4 INVX1 name($4)
+   pin(0 2)
+   pin(1 9)
+   pin(2 1)
+   pin(3 2)
+   pin(4 8)
+   pin(5 1)
+  )
+  circuit(5 INVX1 name($5)
+   pin(0 2)
+   pin(1 10)
+   pin(2 1)
+   pin(3 2)
+   pin(4 9)
+   pin(5 1)
+  )
+  circuit(6 INVX1 name($6)
+   pin(0 2)
+   pin(1 11)
+   pin(2 1)
+   pin(3 2)
+   pin(4 10)
+   pin(5 1)
+  )
+  circuit(7 INVX1 name($7)
+   pin(0 2)
+   pin(1 12)
+   pin(2 1)
+   pin(3 2)
+   pin(4 11)
+   pin(5 1)
+  )
+  circuit(8 INVX1 name($8)
+   pin(0 2)
+   pin(1 13)
+   pin(2 1)
+   pin(3 2)
+   pin(4 12)
+   pin(5 1)
+  )
+  circuit(9 INVX1 name($9)
+   pin(0 2)
+   pin(1 14)
+   pin(2 1)
+   pin(3 2)
+   pin(4 13)
+   pin(5 1)
+  )
+  circuit(10 INVX1 name($10)
+   pin(0 2)
+   pin(1 15)
+   pin(2 1)
+   pin(3 2)
+   pin(4 14)
+   pin(5 1)
+  )
+  circuit(11 INVX1 name($11)
+   pin(0 2)
+   pin(1 3)
+   pin(2 1)
+   pin(3 2)
+   pin(4 15)
+   pin(5 1)
+  )
+  circuit(12 INVX1 name($12)
+   pin(0 2)
+   pin(1 5)
+   pin(2 1)
+   pin(3 2)
+   pin(4 3)
+   pin(5 1)
+  )
+
+ )
+)
+
+# Cross reference
+xref(
+ circuit(INVX1 INVX1 match
+  xref(
+   net(4 4 match)
+   net(5 5 match)
+   net(2 2 match)
+   net(6 6 match)
+   net(1 1 match)
+   net(3 3 match)
+   pin(3 3 match)
+   pin(4 4 match)
+   pin(1 1 match)
+   pin(5 5 match)
+   pin(0 0 match)
+   pin(2 2 match)
+   device(2 2 match)
+   device(1 1 match)
+  )
+ )
+ circuit(ND2X1 ND2X1 match
+  xref(
+   net(8 8 match)
+   net(4 4 match)
+   net(6 6 match)
+   net(5 5 match)
+   net(2 2 match)
+   net(7 7 match)
+   net(1 1 match)
+   net(3 3 match)
+   pin(3 3 match)
+   pin(5 5 match)
+   pin(4 4 match)
+   pin(1 1 match)
+   pin(6 6 match)
+   pin(0 0 match)
+   pin(2 2 match)
+   device(3 3 match)
+   device(4 4 match)
+   device(1 1 match)
+   device(2 2 match)
+  )
+ )
+ circuit(RINGO RINGO match
+  xref(
+   net(1 6 match)
+   net(10 15 match)
+   net(2 7 match)
+   net(3 8 match)
+   net(4 9 match)
+   net(5 10 match)
+   net(6 11 match)
+   net(7 12 match)
+   net(8 13 match)
+   net(9 14 match)
+   net(14 4 match)
+   net(11 3 match)
+   net(13 5 match)
+   net(12 2 match)
+   net(15 1 match)
+   pin(3 3 match)
+   pin(0 2 match)
+   pin(2 4 match)
+   pin(1 1 match)
+   pin(4 0 match)
+   circuit(2 2 match)
+   circuit(3 3 match)
+   circuit(4 4 match)
+   circuit(5 5 match)
+   circuit(6 6 match)
+   circuit(7 7 match)
+   circuit(8 8 match)
+   circuit(9 9 match)
+   circuit(10 10 match)
+   circuit(11 11 match)
+   circuit(12 12 match)
+   circuit(1 1 match)
+  )
+ )
+)