diff --git a/common/nextpnr.cc b/common/nextpnr.cc
index d29d3fec..188906e2 100644
--- a/common/nextpnr.cc
+++ b/common/nextpnr.cc
@@ -97,20 +97,12 @@ uint32_t Context::checksum() const
         for (auto &w : ni.wires) {
             uint32_t wire_x = 123456789;
             wire_x = xorshift32(wire_x + xorshift32(getWireChecksum(w.first)));
-            wire_x = xorshift32(wire_x + xorshift32(getPipChecksum(w.second)));
+            wire_x = xorshift32(wire_x + xorshift32(getPipChecksum(w.second.pip)));
+            wire_x = xorshift32(wire_x + xorshift32(int(w.second.strength)));
             wire_x_sum += wire_x;
         }
         x = xorshift32(x + xorshift32(wire_x_sum));
 
-        uint32_t pip_x_sum = 0;
-        for (auto &p : ni.pips) {
-            uint32_t pip_x = 123456789;
-            pip_x = xorshift32(pip_x + xorshift32(getPipChecksum(p.first)));
-            pip_x = xorshift32(pip_x + xorshift32(p.second));
-            pip_x_sum += pip_x;
-        }
-        x = xorshift32(x + xorshift32(pip_x_sum));
-
         cksum_nets_sum += x;
     }
     cksum = xorshift32(cksum + xorshift32(cksum_nets_sum));
@@ -175,4 +167,32 @@ uint32_t Context::checksum() const
     return cksum;
 }
 
+void Context::check() const
+{
+    for (auto &n : nets) {
+        auto ni = n.second;
+        assert(n.first == ni->name);
+        for (auto &w : ni->wires) {
+            assert(n.first == getBoundWireNet(w.first));
+            if (w.second.pip != PipId()) {
+                assert(w.first == getPipDstWire(w.second.pip));
+                assert(n.first == getBoundPipNet(w.second.pip));
+            }
+        }
+    }
+
+    for (auto w : getWires()) {
+        IdString net = getBoundWireNet(w);
+        if (net != IdString()) {
+            assert(nets.at(net)->wires.count(w));
+        }
+    }
+
+    for (auto &c : cells) {
+        assert(c.first == c.second->name);
+        if (c.second->bel != BelId())
+            assert(getBoundBelCell(c.second->bel) == c.first);
+    }
+}
+
 NEXTPNR_NAMESPACE_END
diff --git a/common/nextpnr.h b/common/nextpnr.h
index 9c6c9d68..8cbead7d 100644
--- a/common/nextpnr.h
+++ b/common/nextpnr.h
@@ -211,6 +211,12 @@ struct PortRef
     delay_t budget = 0;
 };
 
+struct PipMap
+{
+    PipId pip = PipId();
+    PlaceStrength strength = STRENGTH_NONE;
+};
+
 struct NetInfo
 {
     IdString name;
@@ -219,9 +225,7 @@ struct NetInfo
     std::unordered_map<IdString, std::string> attrs;
 
     // wire -> uphill_pip
-    std::unordered_map<WireId, PipId> wires;
-
-    std::unordered_map<PipId, PlaceStrength> pips;
+    std::unordered_map<WireId, PipMap> wires;
 };
 
 enum PortType
@@ -357,6 +361,7 @@ struct Context : Arch
     }
 
     uint32_t checksum() const;
+    void check() const;
 };
 
 NEXTPNR_NAMESPACE_END
diff --git a/common/place_sa.cc b/common/place_sa.cc
index 6743e0ce..f4fb5aff 100644
--- a/common/place_sa.cc
+++ b/common/place_sa.cc
@@ -103,9 +103,7 @@ class SAPlacer
                               cell->name.c_str(ctx), cell->type.c_str(ctx));
                 }
 
-                cell->bel = bel;
-                cell->belStrength = STRENGTH_USER;
-                ctx->bindBel(bel, cell->name);
+                ctx->bindBel(bel, cell->name, STRENGTH_USER);
                 locked_bels.insert(bel);
                 placed_cells++;
             }
@@ -231,7 +229,7 @@ class SAPlacer
         }
         // Final post-pacement validitiy check
         for (auto bel : ctx->getBels()) {
-            IdString cell = ctx->getBelCell(bel, false);
+            IdString cell = ctx->getBoundBelCell(bel);
             if (!checker->isBelLocationValid(bel)) {
                 std::string cell_text = "no cell";
                 if (cell != IdString())
@@ -266,7 +264,6 @@ class SAPlacer
             BelId ripup_bel = BelId();
             if (cell->bel != BelId()) {
                 ctx->unbindBel(cell->bel);
-                cell->bel = BelId();
             }
             BelType targetType = ctx->belTypeFromId(cell->type);
             for (auto bel : ctx->getBels()) {
@@ -283,7 +280,7 @@ class SAPlacer
                         if (score <= best_ripup_score) {
                             best_ripup_score = score;
                             ripup_target =
-                                    ctx->cells.at(ctx->getBelCell(bel, true));
+                                    ctx->cells.at(ctx->getBoundBelCell(bel));
                             ripup_bel = bel;
                         }
                     }
@@ -295,14 +292,11 @@ class SAPlacer
                               cell->name.c_str(ctx), cell->type.c_str(ctx));
                 --iters;
                 ctx->unbindBel(ripup_target->bel);
-                ripup_target->bel = BelId();
                 best_bel = ripup_bel;
             } else {
                 all_placed = true;
             }
-            cell->bel = best_bel;
-            cell->belStrength = STRENGTH_WEAK;
-            ctx->bindBel(cell->bel, cell->name);
+            ctx->bindBel(best_bel, cell->name, STRENGTH_WEAK);
 
             // Back annotate location
             cell->attrs[ctx->id("BEL")] = ctx->getBelName(cell->bel).str(ctx);
@@ -375,7 +369,7 @@ class SAPlacer
         new_lengths.clear();
         update.clear();
         BelId oldBel = cell->bel;
-        IdString other = ctx->getBelCell(newBel, true);
+        IdString other = ctx->getBoundBelCell(newBel);
         CellInfo *other_cell = nullptr;
         wirelen_t new_wirelength = 0, delta;
         ctx->unbindBel(oldBel);
@@ -394,10 +388,10 @@ class SAPlacer
                     update.insert(port.second.net);
         }
 
-        ctx->bindBel(newBel, cell->name);
+        ctx->bindBel(newBel, cell->name, STRENGTH_WEAK);
 
         if (other != IdString()) {
-            ctx->bindBel(oldBel, other_cell->name);
+            ctx->bindBel(oldBel, other_cell->name, STRENGTH_WEAK);
         }
 
         if (!checker->isBelLocationValid(newBel) ||
@@ -408,10 +402,6 @@ class SAPlacer
             goto swap_fail;
         }
 
-        cell->bel = newBel;
-        if (other != IdString())
-            other_cell->bel = oldBel;
-
         new_wirelength = curr_wirelength;
 
         // Recalculate wirelengths for all nets touched by the peturbation
@@ -442,11 +432,9 @@ class SAPlacer
 
         return true;
     swap_fail:
-        ctx->bindBel(oldBel, cell->name);
-        cell->bel = oldBel;
+        ctx->bindBel(oldBel, cell->name, STRENGTH_WEAK);
         if (other != IdString()) {
-            ctx->bindBel(newBel, other);
-            other_cell->bel = newBel;
+            ctx->bindBel(newBel, other, STRENGTH_WEAK);
         }
         return false;
     }
@@ -498,8 +486,14 @@ bool place_design_sa(Context *ctx, bool timing_driven)
         SAPlacer placer(ctx, timing_driven);
         placer.place();
         log_info("Checksum: 0x%08x\n", ctx->checksum());
+#ifndef NDEBUG
+        ctx->check();
+#endif
         return true;
     } catch (log_execution_error_exception) {
+#ifndef NDEBUG
+        ctx->check();
+#endif
         return false;
     }
 }
diff --git a/common/route.cc b/common/route.cc
index a60f1c41..fe2c05e4 100644
--- a/common/route.cc
+++ b/common/route.cc
@@ -79,14 +79,26 @@ struct RipupScoreboard
 void ripup_net(Context *ctx, IdString net_name)
 {
     auto net_info = ctx->nets.at(net_name);
+    std::vector<PipId> pips;
+    std::vector<WireId> wires;
+
+    pips.reserve(net_info->wires.size());
+    wires.reserve(net_info->wires.size());
 
     for (auto &it : net_info->wires) {
-        if (it.second != PipId())
-            ctx->unbindPip(it.second);
-        ctx->unbindWire(it.first);
+        if (it.second.pip != PipId())
+            pips.push_back(it.second.pip);
+        else
+            wires.push_back(it.first);
     }
 
-    net_info->wires.clear();
+    for (auto pip : pips)
+        ctx->unbindPip(pip);
+
+    for (auto wire : wires)
+        ctx->unbindWire(wire);
+
+    assert(net_info->wires.empty());
 }
 
 struct Router
@@ -147,7 +159,7 @@ struct Router
                 if (!ctx->checkWireAvail(next_wire)) {
                     if (!ripup)
                         continue;
-                    IdString ripupWireNet = ctx->getWireNet(next_wire, true);
+                    IdString ripupWireNet = ctx->getConflictingWireNet(next_wire);
                     if (ripupWireNet == net_name || ripupWireNet == IdString())
                         continue;
                     auto it = scores.wireScores.find(
@@ -160,7 +172,7 @@ struct Router
                 if (!ctx->checkPipAvail(pip)) {
                     if (!ripup)
                         continue;
-                    IdString ripupPipNet = ctx->getPipNet(pip, true);
+                    IdString ripupPipNet = ctx->getConflictingPipNet(pip);
                     if (ripupPipNet == net_name || ripupPipNet == IdString())
                         continue;
                     auto it = scores.pipScores.find(
@@ -280,8 +292,7 @@ struct Router
 
         std::unordered_map<WireId, delay_t> src_wires;
         src_wires[src_wire] = 0;
-        net_info->wires[src_wire] = PipId();
-        ctx->bindWire(src_wire, net_name);
+        ctx->bindWire(src_wire, net_name, STRENGTH_WEAK);
 
         std::vector<PortRef> users_array = net_info->users;
         ctx->shuffle(users_array);
@@ -361,9 +372,9 @@ struct Router
                 if (src_wires.count(cursor))
                     break;
 
-                IdString conflicting_wire_net = ctx->getWireNet(cursor, true);
+                IdString conflicting_wire_net = ctx->getConflictingWireNet(cursor);
                 IdString conflicting_pip_net =
-                        ctx->getPipNet(visited[cursor].pip, true);
+                        ctx->getConflictingPipNet(visited[cursor].pip);
 
                 if (conflicting_wire_net != IdString()) {
                     assert(ripup);
@@ -388,10 +399,7 @@ struct Router
                                                     visited[cursor].pip)]++;
                 }
 
-                net_info->wires[cursor] = visited[cursor].pip;
-                ctx->bindWire(cursor, net_name);
-                ctx->bindPip(visited[cursor].pip, net_name);
-
+                ctx->bindPip(visited[cursor].pip, net_name, STRENGTH_WEAK);
                 src_wires[cursor] = visited[cursor].delay;
                 cursor = ctx->getPipSrcWire(visited[cursor].pip);
             }
@@ -495,6 +503,9 @@ bool route_design(Context *ctx)
             if (iterCnt == 200) {
                 log_warning("giving up after %d iterations.\n", iterCnt);
                 log_info("Checksum: 0x%08x\n", ctx->checksum());
+#ifndef NDEBUG
+                ctx->check();
+#endif
                 return false;
             }
 
@@ -655,8 +666,14 @@ bool route_design(Context *ctx)
                  (100.0 * totalOvertimeRevisitCnt) / totalVisitCnt);
 
         log_info("Checksum: 0x%08x\n", ctx->checksum());
+#ifndef NDEBUG
+        ctx->check();
+#endif
         return true;
     } catch (log_execution_error_exception) {
+#ifndef NDEBUG
+        ctx->check();
+#endif
         return false;
     }
 }
diff --git a/dummy/arch.cc b/dummy/arch.cc
index 64c0ca1e..4adff2ca 100644
--- a/dummy/arch.cc
+++ b/dummy/arch.cc
@@ -36,16 +36,15 @@ IdString Arch::getBelName(BelId bel) const { return IdString(); }
 
 uint32_t Arch::getBelChecksum(BelId bel) const { return 0; }
 
-void Arch::bindBel(BelId bel, IdString cell) {}
+void Arch::bindBel(BelId bel, IdString cell, PlaceStrength strength) {}
 
 void Arch::unbindBel(BelId bel) {}
 
 bool Arch::checkBelAvail(BelId bel) const { return false; }
 
-IdString Arch::getBelCell(BelId bel, bool conflicting) const
-{
-    return IdString();
-}
+IdString Arch::getBoundBelCell(BelId bel) const { return IdString(); }
+
+IdString Arch::getConflictingBelCell(BelId bel) const { return IdString(); }
 
 const std::vector<BelId> &Arch::getBels() const
 {
@@ -79,16 +78,15 @@ IdString Arch::getWireName(WireId wire) const { return IdString(); }
 
 uint32_t Arch::getWireChecksum(WireId wire) const { return 0; }
 
-void Arch::bindWire(WireId wire, IdString net) {}
+void Arch::bindWire(WireId wire, IdString net, PlaceStrength strength) {}
 
 void Arch::unbindWire(WireId wire) {}
 
 bool Arch::checkWireAvail(WireId wire) const { return false; }
 
-IdString Arch::getWireNet(WireId wire, bool conflicting) const
-{
-    return IdString();
-}
+IdString Arch::getBoundWireNet(WireId wire) const { return IdString(); }
+
+IdString Arch::getConflictingWireNet(WireId wire) const { return IdString(); }
 
 const std::vector<WireId> &Arch::getWires() const
 {
@@ -104,16 +102,15 @@ IdString Arch::getPipName(PipId pip) const { return IdString(); }
 
 uint32_t Arch::getPipChecksum(PipId wire) const { return 0; }
 
-void Arch::bindPip(PipId pip, IdString net) {}
+void Arch::bindPip(PipId pip, IdString net, PlaceStrength strength) {}
 
 void Arch::unbindPip(PipId pip) {}
 
 bool Arch::checkPipAvail(PipId pip) const { return false; }
 
-IdString Arch::getPipNet(PipId pip, bool conflicting) const
-{
-    return IdString();
-}
+IdString Arch::getBoundPipNet(PipId pip) const { return IdString(); }
+
+IdString Arch::getConflictingPipNet(PipId pip) const { return IdString(); }
 
 const std::vector<PipId> &Arch::getPips() const
 {
diff --git a/dummy/arch.h b/dummy/arch.h
index 5bdf633e..2a778689 100644
--- a/dummy/arch.h
+++ b/dummy/arch.h
@@ -88,10 +88,11 @@ struct Arch : BaseCtx
     BelId getBelByName(IdString name) const;
     IdString getBelName(BelId bel) const;
     uint32_t getBelChecksum(BelId bel) const;
-    void bindBel(BelId bel, IdString cell);
+    void bindBel(BelId bel, IdString cell, PlaceStrength strength);
     void unbindBel(BelId bel);
     bool checkBelAvail(BelId bel) const;
-    IdString getBelCell(BelId bel, bool conflicting = false) const;
+    IdString getBoundBelCell(BelId bel) const;
+    IdString getConflictingBelCell(BelId bel) const;
     const std::vector<BelId> &getBels() const;
     const std::vector<BelId> &getBelsByType(BelType type) const;
     BelType getBelType(BelId bel) const;
@@ -102,19 +103,21 @@ struct Arch : BaseCtx
     WireId getWireByName(IdString name) const;
     IdString getWireName(WireId wire) const;
     uint32_t getWireChecksum(WireId wire) const;
-    void bindWire(WireId wire, IdString net);
+    void bindWire(WireId wire, IdString net, PlaceStrength strength);
     void unbindWire(WireId wire);
     bool checkWireAvail(WireId wire) const;
-    IdString getWireNet(WireId wire, bool conflicting = false) const;
+    IdString getBoundWireNet(WireId wire) const;
+    IdString getConflictingWireNet(WireId wire) const;
     const std::vector<WireId> &getWires() const;
 
     PipId getPipByName(IdString name) const;
     IdString getPipName(PipId pip) const;
     uint32_t getPipChecksum(PipId pip) const;
-    void bindPip(PipId pip, IdString net);
+    void bindPip(PipId pip, IdString net, PlaceStrength strength);
     void unbindPip(PipId pip);
     bool checkPipAvail(PipId pip) const;
-    IdString getPipNet(PipId pip, bool conflicting = false) const;
+    IdString getBoundPipNet(PipId pip) const;
+    IdString getConflictingPipNet(PipId pip) const;
     const std::vector<PipId> &getPips() const;
     WireId getPipSrcWire(PipId pip) const;
     WireId getPipDstWire(PipId pip) const;
diff --git a/ice40/arch.h b/ice40/arch.h
index a6b70a69..26504cff 100644
--- a/ice40/arch.h
+++ b/ice40/arch.h
@@ -533,17 +533,21 @@ struct Arch : BaseCtx
 
     uint32_t getBelChecksum(BelId bel) const { return bel.index; }
 
-    void bindBel(BelId bel, IdString cell)
+    void bindBel(BelId bel, IdString cell, PlaceStrength strength)
     {
         assert(bel != BelId());
         assert(bel_to_cell[bel.index] == IdString());
         bel_to_cell[bel.index] = cell;
+        cells[cell]->bel = bel;
+        cells[cell]->belStrength = strength;
     }
 
     void unbindBel(BelId bel)
     {
         assert(bel != BelId());
         assert(bel_to_cell[bel.index] != IdString());
+        cells[bel_to_cell[bel.index]]->bel = BelId();
+        cells[bel_to_cell[bel.index]]->belStrength = STRENGTH_NONE;
         bel_to_cell[bel.index] = IdString();
     }
 
@@ -553,7 +557,13 @@ struct Arch : BaseCtx
         return bel_to_cell[bel.index] == IdString();
     }
 
-    IdString getBelCell(BelId bel, bool conflicting = false) const
+    IdString getBoundBelCell(BelId bel) const
+    {
+        assert(bel != BelId());
+        return bel_to_cell[bel.index];
+    }
+
+    IdString getConflictingBelCell(BelId bel) const
     {
         assert(bel != BelId());
         return bel_to_cell[bel.index];
@@ -627,17 +637,20 @@ struct Arch : BaseCtx
 
     uint32_t getWireChecksum(WireId wire) const { return wire.index; }
 
-    void bindWire(WireId wire, IdString net)
+    void bindWire(WireId wire, IdString net, PlaceStrength strength)
     {
         assert(wire != WireId());
         assert(wire_to_net[wire.index] == IdString());
         wire_to_net[wire.index] = net;
+        nets[net]->wires[wire].pip = PipId();
+        nets[net]->wires[wire].strength = strength;
     }
 
     void unbindWire(WireId wire)
     {
         assert(wire != WireId());
         assert(wire_to_net[wire.index] != IdString());
+        nets[wire_to_net[wire.index]]->wires.erase(wire);
         wire_to_net[wire.index] = IdString();
     }
 
@@ -647,7 +660,13 @@ struct Arch : BaseCtx
         return wire_to_net[wire.index] == IdString();
     }
 
-    IdString getWireNet(WireId wire, bool conflicting = false) const
+    IdString getBoundWireNet(WireId wire) const
+    {
+        assert(wire != WireId());
+        return wire_to_net[wire.index];
+    }
+
+    IdString getConflictingWireNet(WireId wire) const
     {
         assert(wire != WireId());
         return wire_to_net[wire.index];
@@ -668,14 +687,22 @@ struct Arch : BaseCtx
 
     uint32_t getPipChecksum(PipId pip) const { return pip.index; }
 
-    void bindPip(PipId pip, IdString net)
+    void bindPip(PipId pip, IdString net, PlaceStrength strength)
     {
         assert(pip != PipId());
         assert(pip_to_net[pip.index] == IdString());
         assert(switches_locked[chip_info->pip_data[pip.index].switch_index] ==
                IdString());
+
         pip_to_net[pip.index] = net;
         switches_locked[chip_info->pip_data[pip.index].switch_index] = net;
+
+        WireId dst;
+        dst.index = chip_info->pip_data[pip.index].dst;
+        assert(wire_to_net[dst.index] == IdString());
+        wire_to_net[dst.index] = net;
+        nets[net]->wires[dst].pip = pip;
+        nets[net]->wires[dst].strength = strength;
     }
 
     void unbindPip(PipId pip)
@@ -684,6 +711,13 @@ struct Arch : BaseCtx
         assert(pip_to_net[pip.index] != IdString());
         assert(switches_locked[chip_info->pip_data[pip.index].switch_index] !=
                IdString());
+
+        WireId dst;
+        dst.index = chip_info->pip_data[pip.index].dst;
+        assert(wire_to_net[dst.index] != IdString());
+        wire_to_net[dst.index] = IdString();
+        nets[pip_to_net[pip.index]]->wires.erase(dst);
+
         pip_to_net[pip.index] = IdString();
         switches_locked[chip_info->pip_data[pip.index].switch_index] =
                 IdString();
@@ -696,14 +730,18 @@ struct Arch : BaseCtx
                IdString();
     }
 
-    IdString getPipNet(PipId pip, bool conflicting = false) const
+    IdString getBoundPipNet(PipId pip) const
     {
         assert(pip != PipId());
-        if (conflicting)
-            return switches_locked[chip_info->pip_data[pip.index].switch_index];
         return pip_to_net[pip.index];
     }
 
+    IdString getConflictingPipNet(PipId pip) const
+    {
+        assert(pip != PipId());
+        return switches_locked[chip_info->pip_data[pip.index].switch_index];
+    }
+
     AllPipRange getPips() const
     {
         AllPipRange range;
diff --git a/ice40/arch_place.cc b/ice40/arch_place.cc
index 7b79e031..d374b764 100644
--- a/ice40/arch_place.cc
+++ b/ice40/arch_place.cc
@@ -102,7 +102,7 @@ bool PlaceValidityChecker::isBelLocationValid(BelId bel)
     if (ctx->getBelType(bel) == TYPE_ICESTORM_LC) {
         std::vector<const CellInfo *> cells;
         for (auto bel_other : ctx->getBelsAtSameTile(bel)) {
-            IdString cell_other = ctx->getBelCell(bel_other, false);
+            IdString cell_other = ctx->getBoundBelCell(bel_other);
             if (cell_other != IdString()) {
                 const CellInfo *ci_other = ctx->cells[cell_other];
                 cells.push_back(ci_other);
@@ -110,7 +110,7 @@ bool PlaceValidityChecker::isBelLocationValid(BelId bel)
         }
         return logicCellsCompatible(ctx, cells);
     } else {
-        IdString cellId = ctx->getBelCell(bel, false);
+        IdString cellId = ctx->getBoundBelCell(bel);
         if (cellId == IdString())
             return true;
         else
@@ -126,7 +126,7 @@ bool PlaceValidityChecker::isValidBelForCell(CellInfo *cell, BelId bel)
         std::vector<const CellInfo *> cells;
 
         for (auto bel_other : ctx->getBelsAtSameTile(bel)) {
-            IdString cell_other = ctx->getBelCell(bel_other, false);
+            IdString cell_other = ctx->getBoundBelCell(bel_other);
             if (cell_other != IdString()) {
                 const CellInfo *ci_other = ctx->cells[cell_other];
                 cells.push_back(ci_other);
diff --git a/ice40/bitstream.cc b/ice40/bitstream.cc
index c46776a6..58c2e754 100644
--- a/ice40/bitstream.cc
+++ b/ice40/bitstream.cc
@@ -464,7 +464,7 @@ void write_asc(const Context *ctx, std::ostream &out)
     // Write symbols
     // const bool write_symbols = 1;
     for (auto wire : ctx->getWires()) {
-        IdString net = ctx->getWireNet(wire, false);
+        IdString net = ctx->getBoundWireNet(wire);
         if (net != IdString())
             out << ".sym " << wire.index << " " << net.str(ctx) << std::endl;
     }