Working FF example now that constant merging is done.

Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>

6 files changed, 218 insertions, 8 deletions

diff --git a/fpga_interchange/arch.cc b/fpga_interchange/arch.cc
index 0955c376..966d74f3 100644
--- a/fpga_interchange/arch.cc
+++ b/fpga_interchange/arch.cc
@@ -606,6 +606,7 @@ bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay
 
 bool Arch::pack()
 {
+    merge_constant_nets();
     pack_ports();
     return true;
 }
@@ -754,7 +755,7 @@ const std::vector<std::string> Arch::availablePlacers = {"sa",
 const std::string Arch::defaultRouter = "router2";
 const std::vector<std::string> Arch::availableRouters = {"router1", "router2"};
 
-void Arch::map_cell_pins(CellInfo *cell, int32_t mapping) const
+void Arch::map_cell_pins(CellInfo *cell, int32_t mapping)
 {
     cell->cell_mapping = mapping;
     cell->cell_bel_pins.clear();
@@ -766,11 +767,32 @@ void Arch::map_cell_pins(CellInfo *cell, int32_t mapping) const
         IdString bel_pin(pin_map.bel_pin);
 
         if (cell_pin.str(this) == "GND") {
-            // FIXME: Tie this pin to the GND net
+            PortInfo port_info;
+            port_info.name = bel_pin;
+            port_info.type = PORT_IN;
+            port_info.net = nullptr;
+
+            auto result = cell->ports.emplace(bel_pin, port_info);
+            NPNR_ASSERT(result.second);
+
+            cell->cell_bel_pins[bel_pin].push_back(bel_pin);
+
+            connectPort(IdString(chip_info->constants->gnd_net_name), cell->name, bel_pin);
             continue;
         }
+
         if (cell_pin.str(this) == "VCC") {
-            // FIXME: Tie this pin to the VCC net
+            PortInfo port_info;
+            port_info.name = bel_pin;
+            port_info.type = PORT_IN;
+            port_info.net = nullptr;
+
+            auto result = cell->ports.emplace(bel_pin, port_info);
+            NPNR_ASSERT(result.second);
+
+            cell->cell_bel_pins[bel_pin].push_back(bel_pin);
+
+            connectPort(IdString(chip_info->constants->vcc_net_name), cell->name, bel_pin);
             continue;
         }
 
@@ -795,11 +817,30 @@ void Arch::map_cell_pins(CellInfo *cell, int32_t mapping) const
             IdString bel_pin(pin_map.bel_pin);
 
             if (cell_pin.str(this) == "GND") {
-                // FIXME: Tie this pin to the GND net
+                PortInfo port_info;
+                port_info.name = bel_pin;
+                port_info.type = PORT_IN;
+
+                auto result = cell->ports.emplace(bel_pin, port_info);
+                NPNR_ASSERT(result.second);
+
+                cell->cell_bel_pins[bel_pin].push_back(bel_pin);
+
+                connectPort(IdString(chip_info->constants->gnd_net_name), cell->name, bel_pin);
                 continue;
             }
+
             if (cell_pin.str(this) == "VCC") {
-                // FIXME: Tie this pin to the VCC net
+                PortInfo port_info;
+                port_info.name = bel_pin;
+                port_info.type = PORT_IN;
+
+                auto result = cell->ports.emplace(bel_pin, port_info);
+                NPNR_ASSERT(result.second);
+
+                cell->cell_bel_pins[bel_pin].push_back(bel_pin);
+
+                connectPort(IdString(chip_info->constants->vcc_net_name), cell->name, bel_pin);
                 continue;
             }
 
@@ -858,6 +899,142 @@ size_t Arch::get_cell_type_index(IdString cell_type) const
     return cell_offset;
 }
 
+void Arch::merge_constant_nets() {
+    NetInfo* gnd_net = nullptr;
+    NetInfo* vcc_net = nullptr;
+
+    bool need_gnd_source = false;
+    bool need_vcc_source = false;
+
+    IdString gnd_net_name(chip_info->constants->gnd_net_name);
+    IdString gnd_cell_type(chip_info->constants->gnd_cell_name);
+    IdString gnd_cell_port(chip_info->constants->gnd_cell_port);
+
+    auto gnd_iter = nets.find(gnd_net_name);
+    if(gnd_iter != nets.end()) {
+        NPNR_ASSERT(gnd_iter->second->driver.cell != nullptr);
+        NPNR_ASSERT(gnd_iter->second->driver.cell->type == gnd_cell_type);
+        NPNR_ASSERT(gnd_iter->second->driver.port == gnd_cell_port);
+
+        gnd_net = gnd_iter->second.get();
+    } else {
+        gnd_net = createNet(gnd_net_name);
+        need_gnd_source = true;
+    }
+
+    IdString vcc_net_name(chip_info->constants->vcc_net_name);
+    IdString vcc_cell_type(chip_info->constants->vcc_cell_name);
+    IdString vcc_cell_port(chip_info->constants->vcc_cell_port);
+
+    auto vcc_iter = nets.find(vcc_net_name);
+    if(vcc_iter != nets.end()) {
+        NPNR_ASSERT(vcc_iter->second->driver.cell != nullptr);
+        NPNR_ASSERT(vcc_iter->second->driver.cell->type == vcc_cell_type);
+        NPNR_ASSERT(vcc_iter->second->driver.port == vcc_cell_port);
+
+        vcc_net = vcc_iter->second.get();
+    } else {
+        vcc_net = createNet(vcc_net_name);
+        need_vcc_source = true;
+    }
+
+    std::vector<IdString> other_gnd_nets;
+    std::vector<IdString> other_vcc_nets;
+
+    for(auto & net_pair : nets) {
+        if(net_pair.first == gnd_net_name) {
+            NPNR_ASSERT(net_pair.second.get() == gnd_net);
+            continue;
+        }
+
+        if(net_pair.first == vcc_net_name) {
+            NPNR_ASSERT(net_pair.second.get() == vcc_net);
+            continue;
+        }
+
+        NetInfo *net = net_pair.second.get();
+        if(net->driver.cell == nullptr) {
+            continue;
+        }
+
+        if(net->driver.cell->type == gnd_cell_type) {
+            NPNR_ASSERT(net->driver.port == gnd_cell_port);
+
+            other_gnd_nets.push_back(net_pair.first);
+
+            if(need_gnd_source) {
+                IdString driver_cell = net->driver.cell->name;
+                disconnectPort(driver_cell, gnd_cell_port);
+                connectPort(gnd_net_name, driver_cell, gnd_cell_port);
+                need_gnd_source = false;
+            }
+
+            NPNR_ASSERT(net->driver.port == gnd_cell_port);
+            std::vector<PortRef> users_copy = net->users;
+            for(const PortRef & port_ref : users_copy) {
+                IdString cell = port_ref.cell->name;
+                disconnectPort(cell, port_ref.port);
+                connectPort(gnd_net_name, cell, port_ref.port);
+            }
+        }
+
+        if(net->driver.cell->type == vcc_cell_type) {
+            NPNR_ASSERT(net->driver.port == vcc_cell_port);
+
+            other_vcc_nets.push_back(net_pair.first);
+
+            if(need_vcc_source) {
+                IdString driver_cell = net->driver.cell->name;
+                disconnectPort(driver_cell, vcc_cell_port);
+                connectPort(vcc_net_name, driver_cell, vcc_cell_port);
+                need_vcc_source = false;
+            }
+
+            NPNR_ASSERT(net->driver.port == vcc_cell_port);
+            std::vector<PortRef> users_copy = net->users;
+            for(const PortRef & port_ref : users_copy) {
+                IdString cell = port_ref.cell->name;
+                disconnectPort(cell, port_ref.port);
+                connectPort(vcc_net_name, cell, port_ref.port);
+            }
+        }
+    }
+
+    for(IdString other_gnd_net : other_gnd_nets) {
+        NetInfo * net = getNetByAlias(other_gnd_net);
+        NPNR_ASSERT(net->users.empty());
+    }
+
+    for(IdString other_vcc_net : other_vcc_nets) {
+        NetInfo * net = getNetByAlias(other_vcc_net);
+        NPNR_ASSERT(net->users.empty());
+    }
+
+    for(IdString other_gnd_net : other_gnd_nets) {
+        NPNR_ASSERT(nets.erase(other_gnd_net));
+        gnd_net->aliases.push_back(other_gnd_net);
+        net_aliases[other_gnd_net] = gnd_net_name;
+    }
+
+    for(IdString other_vcc_net : other_vcc_nets) {
+        NPNR_ASSERT(nets.erase(other_vcc_net));
+        vcc_net->aliases.push_back(other_vcc_net);
+        net_aliases[other_vcc_net] = vcc_net_name;
+    }
+
+    if(need_gnd_source) {
+        CellInfo * gnd_cell = createCell(gnd_cell_type, gnd_cell_type);
+        gnd_cell->addOutput(gnd_cell_port);
+        connectPort(gnd_net_name, gnd_cell_type, gnd_cell_port);
+    }
+
+    if(need_vcc_source) {
+        CellInfo * vcc_cell = createCell(vcc_cell_type, vcc_cell_type);
+        vcc_cell->addOutput(vcc_cell_port);
+        connectPort(vcc_net_name, vcc_cell_type, vcc_cell_port);
+    }
+}
+
 // Instance constraint templates.
 template void Arch::ArchConstraints::bindBel(Arch::ArchConstraints::TagState *, const Arch::ConstraintRange);
 template void Arch::ArchConstraints::unbindBel(Arch::ArchConstraints::TagState *, const Arch::ConstraintRange);
diff --git a/fpga_interchange/arch.h b/fpga_interchange/arch.h
index 780382ec..c713ddb9 100644
--- a/fpga_interchange/arch.h
+++ b/fpga_interchange/arch.h
@@ -871,7 +871,7 @@ struct Arch : ArchAPI<ArchRanges>
 
     uint32_t getBelChecksum(BelId bel) const override { return bel.index; }
 
-    void map_cell_pins(CellInfo *cell, int32_t mapping) const;
+    void map_cell_pins(CellInfo *cell, int32_t mapping);
     void map_port_pins(BelId bel, CellInfo *cell) const;
 
     TileStatus &get_tile_status(int32_t tile)
@@ -1716,6 +1716,8 @@ struct Arch : ArchAPI<ArchRanges>
             return is_bel_synthetic(bel);
         }
     }
+
+    void merge_constant_nets();
 };
 
 NEXTPNR_NAMESPACE_END
diff --git a/fpga_interchange/archdefs.h b/fpga_interchange/archdefs.h
index 75af6974..33d999bb 100644
--- a/fpga_interchange/archdefs.h
+++ b/fpga_interchange/archdefs.h
@@ -106,6 +106,7 @@ struct ArchCellInfo
 
     int32_t cell_mapping;
     std::unordered_map<IdString, std::vector<IdString>> cell_bel_pins;
+    std::unordered_set<IdString> const_ports;
 };
 
 NEXTPNR_NAMESPACE_END
diff --git a/fpga_interchange/examples/template.mk b/fpga_interchange/examples/template.mk
index d12a4e11..c795544e 100644
--- a/fpga_interchange/examples/template.mk
+++ b/fpga_interchange/examples/template.mk
@@ -55,6 +55,15 @@ verbose: build/$(DESIGN).netlist
 		--package $(PACKAGE) \
 		--verbose
 
+verbose2: build/$(DESIGN).netlist
+	$(NEXTPNR_BIN) \
+		--chipdb $(BBA_PATH) \
+		--xdc $(DESIGN).xdc \
+		--netlist build/$(DESIGN).netlist \
+		--phys build/$(DESIGN).phys \
+		--package $(PACKAGE) \
+		--debug
+
 debug: build/$(DESIGN).netlist
 	gdb --args $(NEXTPNR_BIN) \
 		--chipdb $(BBA_PATH) \
@@ -63,6 +72,15 @@ debug: build/$(DESIGN).netlist
 		--phys build/$(DESIGN).phys \
 		--package $(PACKAGE)
 
+debug_verbose: build/$(DESIGN).netlist
+	gdb --args $(NEXTPNR_BIN) \
+		--chipdb $(BBA_PATH) \
+		--xdc $(DESIGN).xdc \
+		--netlist build/$(DESIGN).netlist \
+		--phys build/$(DESIGN).phys \
+		--package $(PACKAGE) \
+		--verbose
+
 build/$(DESIGN).dcp: build/$(DESIGN).netlist build/$(DESIGN).phys $(DESIGN).xdc
 	RAPIDWRIGHT_PATH=$(RAPIDWRIGHT_PATH) \
 		$(RAPIDWRIGHT_PATH)/scripts/invoke_rapidwright.sh \
diff --git a/fpga_interchange/examples/wire/wire.xdc b/fpga_interchange/examples/wire/wire.xdc
index e1fce5f0..c923f0fc 100644
--- a/fpga_interchange/examples/wire/wire.xdc
+++ b/fpga_interchange/examples/wire/wire.xdc
@@ -1,2 +1,5 @@
 set_property PACKAGE_PIN N16 [get_ports i]
 set_property PACKAGE_PIN N15 [get_ports o]
+
+set_property IOSTANDARD LVCMOS33 [get_ports i]
+set_property IOSTANDARD LVCMOS33 [get_ports o]
diff --git a/fpga_interchange/fpga_interchange.cpp b/fpga_interchange/fpga_interchange.cpp
index fd57e09c..027513c8 100644
--- a/fpga_interchange/fpga_interchange.cpp
+++ b/fpga_interchange/fpga_interchange.cpp
@@ -269,8 +269,10 @@ static void find_non_synthetic_edges(const Context * ctx, WireId root_wire,
 
         auto downhill_iter = pip_downhill.find(wire);
         if(downhill_iter == pip_downhill.end()) {
-            log_warning("Wire %s never entered the real fabric?\n",
-                    ctx->nameOfWire(wire));
+            if(root_wire != wire) {
+                log_warning("Wire %s never entered the real fabric?\n",
+                        ctx->nameOfWire(wire));
+            }
             continue;
         }
 
@@ -365,6 +367,9 @@ void FpgaInterchange::write_physical_netlist(const Context * ctx, const std::str
             // Don't emit pin map for ports.
             size_t pin_count = 0;
             for(const auto & pin : cell.cell_bel_pins) {
+                if(cell.const_ports.count(pin.first)) {
+                    continue;
+                }
                 pin_count += pin.second.size();
             }
 
@@ -372,6 +377,10 @@ void FpgaInterchange::write_physical_netlist(const Context * ctx, const std::str
             auto pin_iter = pins.begin();
 
             for(const auto & cell_to_bel_pins : cell.cell_bel_pins) {
+                if(cell.const_ports.count(cell_to_bel_pins.first)) {
+                    continue;
+                }
+
                 std::string cell_pin = cell_to_bel_pins.first.str(ctx);
                 size_t cell_pin_index = strings.get_index(cell_pin);