Merge pull request #639 from litghost/parameter_iteration

Update parameter processing based on new DeviceResources metadata

8 files changed, 446 insertions, 44 deletions

diff --git a/.github/ci/build_interchange.sh b/.github/ci/build_interchange.sh
index 14b129fa..ec70f478 100755
--- a/.github/ci/build_interchange.sh
+++ b/.github/ci/build_interchange.sh
@@ -26,7 +26,7 @@ popd
 RAPIDWRIGHT_PATH="`pwd`/RapidWright"
 INTERCHANGE_SCHEMA_PATH="`pwd`/3rdparty/fpga-interchange-schema/interchange"
 PYTHON_INTERCHANGE_PATH="`pwd`/python-fpga-interchange"
-PYTHON_INTERCHANGE_TAG="v0.0.2"
+PYTHON_INTERCHANGE_TAG="v0.0.3"
 
 # Install python-fpga-interchange libraries
 git clone -b $PYTHON_INTERCHANGE_TAG https://github.com/SymbiFlow/python-fpga-interchange.git $PYTHON_INTERCHANGE_PATH
diff --git a/common/dynamic_bitarray.h b/common/dynamic_bitarray.h
index 605d59d5..be41835b 100644
--- a/common/dynamic_bitarray.h
+++ b/common/dynamic_bitarray.h
@@ -24,6 +24,8 @@
 #include <limits>
 #include <vector>
 
+#include "log.h"
+#include "nextpnr_assertions.h"
 #include "nextpnr_namespaces.h"
 
 NEXTPNR_NAMESPACE_BEGIN
@@ -73,6 +75,133 @@ template <typename Storage = std::vector<uint8_t>> class DynamicBitarray
 
     void clear() { return storage.clear(); }
 
+    // Convert IntType to a DynamicBitarray of sufficent width
+    template <typename IntType> static DynamicBitarray<Storage> to_bitarray(const IntType &value)
+    {
+        if (std::numeric_limits<IntType>::is_signed) {
+            if (value < 0) {
+                log_error("Expected position value, got %s\n", std::to_string(value).c_str());
+            }
+        }
+
+        DynamicBitarray<Storage> result;
+        result.resize(std::numeric_limits<IntType>::digits);
+        result.fill(false);
+
+        // Use a 1 of the right type (for shifting)
+        IntType one(1);
+
+        for (size_t i = 0; i < std::numeric_limits<IntType>::digits; ++i) {
+            if ((value & (one << i)) != 0) {
+                result.set(i, true);
+            }
+        }
+
+        return result;
+    }
+
+    // Convert binary bitstring to a DynamicBitarray of sufficent width
+    //
+    // string must be satisfy the following regex:
+    //
+    //    [01]+
+    //
+    // width can either be specified explicitly, or -1 to use a size wide
+    // enough to store the given string.
+    //
+    // If the width is specified and the width is insufficent it will result
+    // in an error.
+    static DynamicBitarray<Storage> parse_binary_bitstring(int width, const std::string &bits)
+    {
+        NPNR_ASSERT(width == -1 || width > 0);
+
+        DynamicBitarray<Storage> result;
+        // If no width was supplied, use the width from the input data.
+        if (width == -1) {
+            width = bits.size();
+        }
+
+        NPNR_ASSERT(width >= 0);
+        if ((size_t)width < bits.size()) {
+            log_error("String '%s' is wider than specified width %d\n", bits.c_str(), width);
+        }
+        result.resize(width);
+        result.fill(false);
+
+        for (size_t i = 0; i < bits.size(); ++i) {
+            // bits[0] is the MSB!
+            size_t index = width - 1 - i;
+            if (!(bits[i] == '1' || bits[i] == '0')) {
+                log_error("String '%s' is not a valid binary bitstring?\n", bits.c_str());
+            }
+            result.set(index, bits[i] == '1');
+        }
+
+        return result;
+    }
+
+    // Convert hex bitstring to a DynamicBitarray of sufficent width
+    //
+    // string must be satisfy the following regex:
+    //
+    //    [0-9a-fA-F]+
+    //
+    // width can either be specified explicitly, or -1 to use a size wide
+    // enough to store the given string.
+    //
+    // If the width is specified and the width is insufficent it will result
+    // in an error.
+    static DynamicBitarray<Storage> parse_hex_bitstring(int width, const std::string &bits)
+    {
+        NPNR_ASSERT(width == -1 || width > 0);
+
+        DynamicBitarray<Storage> result;
+        // If no width was supplied, use the width from the input data.
+        if (width == -1) {
+            // Each character is 4 bits!
+            width = bits.size() * 4;
+        }
+
+        NPNR_ASSERT(width >= 0);
+        int rem = width % 4;
+        size_t check_width = width;
+        if (rem != 0) {
+            check_width += (4 - rem);
+        }
+        if (check_width < bits.size() * 4) {
+            log_error("String '%s' is wider than specified width %d (check_width = %zu)\n", bits.c_str(), width,
+                      check_width);
+        }
+
+        result.resize(width);
+        result.fill(false);
+
+        size_t index = 0;
+        for (auto nibble_iter = bits.rbegin(); nibble_iter != bits.rend(); ++nibble_iter) {
+            char nibble = *nibble_iter;
+
+            int value;
+            if (nibble >= '0' && nibble <= '9') {
+                value = nibble - '0';
+            } else if (nibble >= 'a' && nibble <= 'f') {
+                value = 10 + (nibble - 'a');
+            } else if (nibble >= 'A' && nibble <= 'F') {
+                value = 10 + (nibble - 'A');
+            } else {
+                log_error("Invalid hex string '%s'?\n", bits.c_str());
+            }
+            NPNR_ASSERT(value >= 0);
+            NPNR_ASSERT(value < 16);
+
+            // Insert nibble into bitarray.
+            for (size_t i = 0; i < 4; ++i) {
+                result.set(index++, (value & (1 << i)) != 0);
+            }
+        }
+
+        return result;
+    }
+
   private:
     Storage storage;
 };
diff --git a/common/property.h b/common/property.h
index 79fbf881..7a377b97 100644
--- a/common/property.h
+++ b/common/property.h
@@ -78,7 +78,7 @@ struct Property
             result.push_back(c == S1);
         return result;
     }
-    std::string as_string() const
+    const std::string &as_string() const
     {
         NPNR_ASSERT(is_string);
         return str;
diff --git a/fpga_interchange/arch.cc b/fpga_interchange/arch.cc
index 476801aa..b5bcc7c5 100644
--- a/fpga_interchange/arch.cc
+++ b/fpga_interchange/arch.cc
@@ -280,6 +280,7 @@ void Arch::init()
     lookahead.init(getCtx(), getCtx());
 #endif
     dedicated_interconnect.init(getCtx());
+    cell_parameters.init(getCtx());
 }
 
 // -----------------------------------------------------------------------
@@ -1095,14 +1096,14 @@ void Arch::map_cell_pins(CellInfo *cell, int32_t mapping, bool bind_constants)
 
     for (const auto &parameter_pin_map : cell_pin_map.parameter_pins) {
         IdString param_key(parameter_pin_map.key);
-        std::string param_value = IdString(parameter_pin_map.value).c_str(this);
+        IdString param_value(parameter_pin_map.value);
 
         auto iter = cell->params.find(param_key);
         if (iter == cell->params.end()) {
             continue;
         }
 
-        if (param_value != iter->second.as_string()) {
+        if (!cell_parameters.compare_property(getCtx(), cell->type, param_key, iter->second, param_value)) {
             continue;
         }
 
@@ -1383,44 +1384,6 @@ void Arch::report_invalid_bel(BelId bel, CellInfo *cell) const
               nameOfBel(bel), mapping);
 }
 
-void Arch::read_lut_equation(DynamicBitarray<> *equation, const Property &equation_parameter) const
-{
-    equation->fill(false);
-    std::string eq_str = equation_parameter.as_string();
-    std::smatch results;
-    if (std::regex_match(eq_str, results, raw_bin_constant)) {
-        size_t bit_idx = 0;
-        const std::string &bits = results[0];
-        NPNR_ASSERT(bits.size() <= equation->size());
-        for (auto bit = bits.rbegin(); bit != bits.rend(); ++bit) {
-            if (*bit == '0') {
-                equation->set(bit_idx++, false);
-            } else {
-                NPNR_ASSERT(*bit == '1');
-                equation->set(bit_idx++, true);
-            }
-        }
-    } else if (std::regex_match(eq_str, results, verilog_bin_constant)) {
-        int iwidth = std::stoi(results[1]);
-        NPNR_ASSERT(iwidth >= 0);
-        size_t width = iwidth;
-        std::string bits = results[2];
-        NPNR_ASSERT(width <= equation->size());
-        NPNR_ASSERT(bits.size() <= width);
-        size_t bit_idx = 0;
-        for (auto bit = bits.rbegin(); bit != bits.rend(); ++bit) {
-            if (*bit == '0') {
-                equation->set(bit_idx++, false);
-            } else {
-                NPNR_ASSERT(*bit == '1');
-                equation->set(bit_idx++, true);
-            }
-        }
-    } else {
-        NPNR_ASSERT(false);
-    }
-}
-
 void Arch::decode_lut_cells()
 {
     for (auto &cell_pair : cells) {
@@ -1443,7 +1406,8 @@ void Arch::decode_lut_cells()
         IdString equation_parameter(lut_cell.parameter);
         const Property &equation = cell->params.at(equation_parameter);
         cell->lut_cell.equation.resize(1 << cell->lut_cell.pins.size());
-        read_lut_equation(&cell->lut_cell.equation, equation);
+
+        cell->lut_cell.equation = cell_parameters.parse_int_like(getCtx(), cell->type, equation_parameter, equation);
     }
 }
 
diff --git a/fpga_interchange/arch.h b/fpga_interchange/arch.h
index d167f797..8e08f17b 100644
--- a/fpga_interchange/arch.h
+++ b/fpga_interchange/arch.h
@@ -34,6 +34,7 @@
 #include "relptr.h"
 
 #include "arch_iterators.h"
+#include "cell_parameters.h"
 #include "chipdb.h"
 #include "dedicated_interconnect.h"
 #include "lookahead.h"
@@ -1045,6 +1046,7 @@ struct Arch : ArchAPI<ArchRanges>
     Lookahead lookahead;
     mutable RouteNodeStorage node_storage;
     mutable SiteRoutingCache site_routing_cache;
+    CellParameters cell_parameters;
 
     std::string chipdb_hash;
     std::string get_chipdb_hash() const;
diff --git a/fpga_interchange/cell_parameters.cc b/fpga_interchange/cell_parameters.cc
new file mode 100644
index 00000000..e008fea8
--- /dev/null
+++ b/fpga_interchange/cell_parameters.cc
@@ -0,0 +1,222 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021  Symbiflow Authors
+ *
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "cell_parameters.h"
+
+#include <limits>
+
+#include "DeviceResources.capnp.h"
+#include "context.h"
+#include "log.h"
+#include "nextpnr_assertions.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+CellParameters::CellParameters()
+        // 1'b0
+        : verilog_binary_re("([1-9][0-9]*)'b([01]+)$"),
+          // 8'hF
+          verilog_hex_re("([1-9][0-9]*)'h([0-9a-fA-F]+)$"),
+          // 0b10
+          c_binary_re("0b([01]+)$"),
+          // 0xF
+          c_hex_re("0x([0-9a-fA-F]+)$")
+{
+}
+
+void CellParameters::init(const Context *ctx)
+{
+    for (const CellParameterPOD &cell_parameter : ctx->chip_info->cell_map->cell_parameters) {
+        IdString cell_type(cell_parameter.cell_type);
+        IdString parameter(cell_parameter.parameter);
+        auto result = parameters.emplace(std::make_pair(cell_type, parameter), &cell_parameter);
+        NPNR_ASSERT(result.second);
+    }
+}
+
+static bool parse_int(const std::string &data, int64_t *result)
+{
+    NPNR_ASSERT(result != nullptr);
+    try {
+        *result = boost::lexical_cast<int64_t>(data);
+        return true;
+    } catch (boost::bad_lexical_cast &e) {
+        return false;
+    }
+}
+
+DynamicBitarray<> CellParameters::parse_int_like(const Context *ctx, IdString cell_type, IdString parameter,
+                                                 const Property &property) const
+{
+    const CellParameterPOD *definition = parameters.at(std::make_pair(cell_type, parameter));
+    DeviceResources::Device::ParameterFormat format;
+    format = static_cast<DeviceResources::Device::ParameterFormat>(definition->format);
+
+    DynamicBitarray<> result;
+    switch (format) {
+    case DeviceResources::Device::ParameterFormat::BOOLEAN:
+        result.resize(1);
+        if (property.is_string) {
+            if (property.as_string() == "TRUE" || property.as_string() == "1") {
+                result.set(0, true);
+            } else if (property.as_string() == "FALSE" || property.as_string() == "0") {
+                result.set(0, false);
+            } else {
+                log_error("Property value %s not expected for BOOLEAN type.\n", property.c_str());
+            }
+        } else {
+            if (property.intval == 1) {
+                result.set(0, true);
+            } else if (property.intval == 0) {
+                result.set(0, false);
+            } else {
+                log_error("Property value %lu not expected for BOOLEAN type.\n", property.intval);
+            }
+        }
+
+        return result;
+    case DeviceResources::Device::ParameterFormat::INTEGER:
+        if (property.is_string) {
+            char *endptr;
+            std::uintmax_t value = strtoumax(property.c_str(), &endptr, /*base=*/10);
+            if (endptr != (property.c_str() + property.size())) {
+                log_error("Property value %s not expected for INTEGER type.\n", property.c_str());
+            }
+
+            return DynamicBitarray<>::to_bitarray(value);
+        } else {
+            return DynamicBitarray<>::to_bitarray(property.intval);
+        }
+        break;
+    case DeviceResources::Device::ParameterFormat::VERILOG_BINARY:
+        if (property.is_string) {
+            std::smatch m;
+            if (!std::regex_match(property.as_string(), m, verilog_binary_re)) {
+                log_error("Property value %s not expected for VERILOG_BINARY type.\n", property.c_str());
+            }
+
+            int64_t width;
+            if (!parse_int(m[1], &width)) {
+                log_error("Failed to parse width from property value %s of type VERILOG_BINARY.\n", property.c_str());
+            }
+            if (width < 0) {
+                log_error("Expected width to be positive for property value %s\n", property.c_str());
+            }
+
+            return DynamicBitarray<>::parse_binary_bitstring(width, m[2]);
+        } else {
+            return DynamicBitarray<>::to_bitarray(property.intval);
+        }
+        break;
+    case DeviceResources::Device::ParameterFormat::VERILOG_HEX:
+        if (property.is_string) {
+            std::smatch m;
+            if (!std::regex_match(property.as_string(), m, verilog_hex_re)) {
+                log_error("Property value %s not expected for VERILOG_HEX type.\n", property.c_str());
+            }
+
+            int64_t width;
+            if (!parse_int(m[1], &width)) {
+                log_error("Failed to parse width from property value %s of type VERILOG_HEX.\n", property.c_str());
+            }
+            if (width < 0) {
+                log_error("Expected width to be positive for property value %s\n", property.c_str());
+            }
+
+            return DynamicBitarray<>::parse_hex_bitstring(width, m[2]);
+        } else {
+            return DynamicBitarray<>::to_bitarray(property.intval);
+        }
+        break;
+    case DeviceResources::Device::ParameterFormat::C_BINARY:
+        if (property.is_string) {
+            std::smatch m;
+            if (!std::regex_match(property.as_string(), m, c_binary_re)) {
+                log_error("Property value %s not expected for C_BINARY type.\n", property.c_str());
+            }
+
+            return DynamicBitarray<>::parse_binary_bitstring(/*width=*/-1, m[1]);
+        } else {
+            return DynamicBitarray<>::to_bitarray(property.intval);
+        }
+        break;
+    case DeviceResources::Device::ParameterFormat::C_HEX:
+        if (property.is_string) {
+            std::smatch m;
+            if (!std::regex_match(property.as_string(), m, c_hex_re)) {
+                log_error("Property value %s not expected for C_HEX type.\n", property.c_str());
+            }
+
+            return DynamicBitarray<>::parse_hex_bitstring(/*width=*/-1, m[1]);
+        } else {
+            return DynamicBitarray<>::to_bitarray(property.intval);
+        }
+        break;
+    default:
+        log_error("Format %d is not int-like\n", definition->format);
+    }
+
+    // Unreachable!
+    NPNR_ASSERT(false);
+}
+
+bool CellParameters::compare_property(const Context *ctx, IdString cell_type, IdString parameter,
+                                      const Property &property, IdString value_to_compare) const
+{
+    const CellParameterPOD *definition = parameters.at(std::make_pair(cell_type, parameter));
+    DeviceResources::Device::ParameterFormat format;
+    format = static_cast<DeviceResources::Device::ParameterFormat>(definition->format);
+
+    switch (format) {
+    case DeviceResources::Device::ParameterFormat::STRING:
+        return value_to_compare.c_str(ctx) == property.as_string();
+    case DeviceResources::Device::ParameterFormat::FLOATING_POINT:
+        // Note: Comparing floating point is pretty weird
+        log_warning("Doing direct comparisions on floating points values is pretty weird, double check this.  Cell "
+                    "type %s parameter %s\n",
+                    cell_type.c_str(ctx), parameter.c_str(ctx));
+        return value_to_compare.c_str(ctx) == property.as_string();
+    case DeviceResources::Device::ParameterFormat::BOOLEAN:
+    case DeviceResources::Device::ParameterFormat::INTEGER:
+    case DeviceResources::Device::ParameterFormat::VERILOG_BINARY:
+    case DeviceResources::Device::ParameterFormat::VERILOG_HEX:
+    case DeviceResources::Device::ParameterFormat::C_BINARY:
+    case DeviceResources::Device::ParameterFormat::C_HEX: {
+        if (property.is_string) {
+            // Given that string presentations should be equivalent if
+            // formatted consistently, this should work most and or all of
+            // the time.  If there are important exceptions, revisit this.
+            return property.as_string() == value_to_compare.c_str(ctx);
+        } else {
+            int64_t int_to_compare;
+            if (!parse_int(value_to_compare.c_str(ctx), &int_to_compare)) {
+                log_error("Comparision failed, to compare value %s is not int-like\n", value_to_compare.c_str(ctx));
+            }
+
+            return property.intval == int_to_compare;
+        }
+    }
+    }
+
+    // Unreachable!
+    NPNR_ASSERT(false);
+}
+
+NEXTPNR_NAMESPACE_END
diff --git a/fpga_interchange/cell_parameters.h b/fpga_interchange/cell_parameters.h
new file mode 100644
index 00000000..3507a81f
--- /dev/null
+++ b/fpga_interchange/cell_parameters.h
@@ -0,0 +1,55 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021  Symbiflow Authors
+ *
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#ifndef CELL_PARAMETERS_H
+#define CELL_PARAMETERS_H
+
+#include <regex>
+
+#include "chipdb.h"
+#include "dynamic_bitarray.h"
+#include "hash_table.h"
+#include "nextpnr_namespaces.h"
+#include "property.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+struct Context;
+
+struct CellParameters
+{
+    CellParameters();
+    void init(const Context *ctx);
+    DynamicBitarray<> parse_int_like(const Context *ctx, IdString cell_type, IdString parameter,
+                                     const Property &property) const;
+    bool compare_property(const Context *ctx, IdString cell_type, IdString parameter, const Property &property,
+                          IdString value_to_compare) const;
+
+    HashTables::HashMap<std::pair<IdString, IdString>, const CellParameterPOD *> parameters;
+
+    std::regex verilog_binary_re;
+    std::regex verilog_hex_re;
+    std::regex c_binary_re;
+    std::regex c_hex_re;
+};
+
+NEXTPNR_NAMESPACE_END
+
+#endif /* CELL_PARAMETERS_H */
diff --git a/fpga_interchange/chipdb.h b/fpga_interchange/chipdb.h
index 2f82dcc9..5c9a9c52 100644
--- a/fpga_interchange/chipdb.h
+++ b/fpga_interchange/chipdb.h
@@ -34,7 +34,7 @@ NEXTPNR_NAMESPACE_BEGIN
  * kExpectedChipInfoVersion
  */
 
-static constexpr int32_t kExpectedChipInfoVersion = 2;
+static constexpr int32_t kExpectedChipInfoVersion = 4;
 
 // Flattened site indexing.
 //
@@ -71,6 +71,15 @@ NPNR_PACKED_STRUCT(struct BelInfoPOD {
     int8_t lut_element;
 
     RelPtr<int32_t> pin_map; // Index into CellMapPOD::cell_bel_map
+
+    // If this BEL is a site routing BEL with inverting pins, these values
+    // will be [0, num_bel_wires).  If this BEL is either not a site routing
+    // BEL or this site routing has no inversion capabilities, then these will
+    // both be -1.
+    int8_t non_inverting_pin;
+    int8_t inverting_pin;
+
+    int16_t padding;
 });
 
 enum BELCategory
@@ -198,6 +207,14 @@ NPNR_PACKED_STRUCT(struct CellConstraintPOD {
     RelSlice<int32_t> states; // State indicies
 });
 
+// Cell parameters metadata
+NPNR_PACKED_STRUCT(struct CellParameterPOD {
+    int32_t cell_type;     // constid
+    int32_t parameter;     // constid
+    int32_t format;        // ParameterFormat enum
+    int32_t default_value; // constid
+});
+
 NPNR_PACKED_STRUCT(struct CellBelMapPOD {
     RelSlice<CellBelPinPOD> common_pins;
     RelSlice<ParameterPinsPOD> parameter_pins;
@@ -218,6 +235,7 @@ NPNR_PACKED_STRUCT(struct CellMapPOD {
     RelSlice<CellBelMapPOD> cell_bel_map;
 
     RelSlice<LutCellPOD> lut_cells;
+    RelSlice<CellParameterPOD> cell_parameters;
 });
 
 NPNR_PACKED_STRUCT(struct PackagePinPOD {
@@ -252,6 +270,10 @@ NPNR_PACKED_STRUCT(struct ConstantsPOD {
 
     // Name to use for the global VCC constant net
     int32_t vcc_net_name; // constid
+
+    // If a choice is available, which constant net should be used?
+    // Can be ''/0 if either constant net are equivilent.
+    int32_t best_constant_net; // constid
 });
 
 NPNR_PACKED_STRUCT(struct ChipInfoPOD {
@@ -306,6 +328,14 @@ inline const SiteInstInfoPOD &site_inst_info(const ChipInfoPOD *chip_info, int32
     return chip_info->sites[chip_info->tiles[tile].sites[site]];
 }
 
+enum SyntheticType
+{
+    NOT_SYNTH = 0,
+    SYNTH_SIGNAL = 1,
+    SYNTH_GND = 2,
+    SYNTH_VCC = 3,
+};
+
 NEXTPNR_NAMESPACE_END
 
 #endif /* CHIPDB_H */