[MSFT] Use a DeviceDB to seed a PlacementDB (#1922)

Just checks validity of placements for now.

include/circt-c/Dialect/MSFT.h

@@ -38,7 +38,7 @@ typedef struct {
   void *ptr;
 } CirctMSFTDeviceDB;
 
-CirctMSFTDeviceDB circtMSFTCreateDeviceDB();
+CirctMSFTDeviceDB circtMSFTCreateDeviceDB(MlirContext);
 void circtMSFTDeleteDeviceDB(CirctMSFTDeviceDB self);
 MlirLogicalResult circtMSFTDeviceDBAddPrimitive(CirctMSFTDeviceDB,
                                                 MlirAttribute locAndPrim);
@@ -60,7 +60,8 @@ typedef struct {
   MlirOperation op;
 } CirctMSFTPlacedInstance;
 
-CirctMSFTPlacementDB circtMSFTCreatePlacementDB(MlirOperation top);
+CirctMSFTPlacementDB circtMSFTCreatePlacementDB(MlirOperation top,
+                                                CirctMSFTDeviceDB seed);
 void circtMSFTDeletePlacementDB(CirctMSFTPlacementDB self);
 size_t circtMSFTPlacementDBAddDesignPlacements(CirctMSFTPlacementDB);
 MlirLogicalResult

include/circt/Dialect/MSFT/DeviceDB.h

@@ -26,13 +26,17 @@ namespace msft {
 class DeviceDB {
 public:
   /// Create a DB treating 'top' as the root module.
-  DeviceDB();
+  DeviceDB(MLIRContext *);
 
   /// Place a primitive at a location.
   LogicalResult addPrimitive(PhysLocationAttr);
   /// Check to see if a primitive exists.
   bool isValidLocation(PhysLocationAttr);
 
+  /// Iterate over all the primitive locations, executing 'callback' on each
+  /// one.
+  void foreach (function_ref<void(PhysLocationAttr)> callback) const;
+
 private:
   using DimPrimitiveType = DenseSet<PrimitiveType>;
   using DimNumMap = DenseMap<size_t, DimPrimitiveType>;
@@ -42,8 +46,10 @@ private:
   /// Get the leaf node. Abstract this out to make it easier to change the
   /// underlying data structure.
   DimPrimitiveType &getLeaf(PhysLocationAttr);
+  // TODO: Create read-only version of getLeaf.
 
   DimXMap placements;
+  MLIRContext *ctxt;
 };
 
 } // namespace msft

include/circt/Dialect/MSFT/PlacementDB.h

@@ -14,6 +14,7 @@
 #ifndef CIRCT_DIALECT_MSFT_PLACEMENTDB_H
 #define CIRCT_DIALECT_MSFT_PLACEMENTDB_H
 
+#include "circt/Dialect/MSFT/DeviceDB.h"
 #include "circt/Dialect/MSFT/MSFTAttributes.h"
 
 #include "mlir/IR/Operation.h"
@@ -34,6 +35,7 @@ class PlacementDB {
 public:
   /// Create a DB treating 'top' as the root module.
   PlacementDB(Operation *top);
+  PlacementDB(Operation *top, const DeviceDB &seed);
 
   // TODO: Add calls to model the device primitive locations.
 
@@ -70,7 +72,12 @@ private:
   using DimYMap = DenseMap<size_t, DimNumMap>;
   using DimXMap = DenseMap<size_t, DimYMap>;
 
+  /// Get the leaf node. Abstract this out to make it easier to change the
+  /// underlying data structure.
+  Optional<PlacedInstance *> getLeaf(PhysLocationAttr);
+
   DimXMap placements;
+  bool seeded;
 };
 
 } // namespace msft

integration_test/Bindings/Python/dialects/msft.py

@@ -95,3 +95,12 @@ with ir.Context() as ctx, ir.Location.unknown():
   assert not devdb.is_valid_location(physAttr)
   devdb.add_primitive(physAttr)
   assert devdb.is_valid_location(physAttr)
+
+  seeded_pdb = msft.PlacementDB(top.operation, devdb)
+  rc = seeded_pdb.add_placement(physAttr, path, "subpath", resolved_inst)
+  assert rc
+
+  bad_loc = msft.PhysLocationAttr.get(msft.M20K, x=7, y=99, num=1)
+  rc = seeded_pdb.add_placement(bad_loc, path, "subpath", resolved_inst)
+  assert not rc
+  # ERR: error: 'hw.instance' op Could not apply placement. Invalid location

lib/Bindings/Python/MSFTModule.cpp

@@ -27,7 +27,7 @@ using namespace mlir::python::adaptors;
 
 class DeviceDB {
 public:
-  DeviceDB() { db = circtMSFTCreateDeviceDB(); }
+  DeviceDB(MlirContext ctxt) { db = circtMSFTCreateDeviceDB(ctxt); }
   ~DeviceDB() { circtMSFTDeleteDeviceDB(db); }
   bool addPrimitive(MlirAttribute locAndPrim) {
     return mlirLogicalResultIsSuccess(
@@ -37,13 +37,15 @@ public:
     return circtMSFTDeviceDBIsValidLocation(db, loc);
   }
 
-private:
   CirctMSFTDeviceDB db;
 };
 
 class PlacementDB {
 public:
-  PlacementDB(MlirOperation top) { db = circtMSFTCreatePlacementDB(top); }
+  PlacementDB(MlirOperation top, DeviceDB *seed) {
+    db = circtMSFTCreatePlacementDB(top, seed ? seed->db
+                                              : CirctMSFTDeviceDB{nullptr});
+  }
   ~PlacementDB() { circtMSFTDeletePlacementDB(db); }
   size_t addDesignPlacements() {
     return circtMSFTPlacementDBAddDesignPlacements(db);
@@ -162,7 +164,7 @@ void circt::python::populateDialectMSFTSubmodule(py::module &m) {
       });
 
   py::class_<DeviceDB>(m, "DeviceDB")
-      .def(py::init<>())
+      .def(py::init<MlirContext>(), py::arg("ctxt") = py::none())
       .def("add_primitive", &DeviceDB::addPrimitive,
            "Inform the DB about a new placement.", py::arg("loc_and_prim"))
       .def("is_valid_location", &DeviceDB::isValidLocation,
@@ -170,7 +172,8 @@ void circt::python::populateDialectMSFTSubmodule(py::module &m) {
            py::arg("loc"));
 
   py::class_<PlacementDB>(m, "PlacementDB")
-      .def(py::init<MlirOperation>(), py::arg("top"))
+      .def(py::init<MlirOperation, DeviceDB *>(), py::arg("top"),
+           py::arg("seed") = nullptr)
       .def("add_design_placements", &PlacementDB::addDesignPlacements,
            "Add the placements already present in the design.")
       .def("add_placement", &PlacementDB::addPlacement,

lib/CAPI/Dialect/MSFT.cpp

@@ -40,7 +40,9 @@ MlirLogicalResult mlirMSFTExportTcl(MlirOperation module,
 
 DEFINE_C_API_PTR_METHODS(CirctMSFTDeviceDB, circt::msft::DeviceDB)
 
-CirctMSFTDeviceDB circtMSFTCreateDeviceDB() { return wrap(new DeviceDB()); }
+CirctMSFTDeviceDB circtMSFTCreateDeviceDB(MlirContext ctxt) {
+  return wrap(new DeviceDB(unwrap(ctxt)));
+}
 void circtMSFTDeleteDeviceDB(CirctMSFTDeviceDB self) { delete unwrap(self); }
 MlirLogicalResult circtMSFTDeviceDBAddPrimitive(CirctMSFTDeviceDB self,
                                                 MlirAttribute cLoc) {
@@ -59,8 +61,11 @@ bool circtMSFTDeviceDBIsValidLocation(CirctMSFTDeviceDB self,
 
 DEFINE_C_API_PTR_METHODS(CirctMSFTPlacementDB, circt::msft::PlacementDB)
 
-CirctMSFTPlacementDB circtMSFTCreatePlacementDB(MlirOperation top) {
-  return wrap(new PlacementDB(unwrap(top)));
+CirctMSFTPlacementDB circtMSFTCreatePlacementDB(MlirOperation top,
+                                                CirctMSFTDeviceDB seed) {
+  if (seed.ptr == nullptr)
+    return wrap(new PlacementDB(unwrap(top)));
+  return wrap(new PlacementDB(unwrap(top), *unwrap(seed)));
 }
 void circtMSFTDeletePlacementDB(CirctMSFTPlacementDB self) {
   delete unwrap(self);

lib/Dialect/MSFT/DeviceDB.cpp

@@ -20,7 +20,7 @@ using namespace msft;
 // not an immediate goal.
 //===----------------------------------------------------------------------===//
 
-DeviceDB::DeviceDB() {}
+DeviceDB::DeviceDB(MLIRContext *ctxt) : ctxt(ctxt) {}
 
 /// Assign an instance to a primitive. Return false if another instance is
 /// already placed at that location.
@@ -44,3 +44,12 @@ bool DeviceDB::isValidLocation(PhysLocationAttr loc) {
 DeviceDB::DimPrimitiveType &DeviceDB::getLeaf(PhysLocationAttr loc) {
   return placements[loc.getX()][loc.getY()][loc.getNum()];
 }
+
+void DeviceDB::foreach (function_ref<void(PhysLocationAttr)> callback) const {
+  for (auto x : placements)
+    for (auto y : x.second)
+      for (auto n : y.second)
+        for (auto p : n.second)
+          callback(PhysLocationAttr::get(ctxt, PrimitiveTypeAttr::get(ctxt, p),
+                                         x.first, y.first, n.first));
+}

lib/Dialect/MSFT/PlacementDB.cpp

@@ -20,18 +20,28 @@ using namespace msft;
 // not an immediate goal.
 //===----------------------------------------------------------------------===//
 
-PlacementDB::PlacementDB(Operation *top) : ctxt(top->getContext()), top(top) {}
+PlacementDB::PlacementDB(Operation *top)
+    : ctxt(top->getContext()), top(top), seeded(false) {}
+PlacementDB::PlacementDB(Operation *top, const DeviceDB &seed)
+    : ctxt(top->getContext()), top(top), seeded(false) {
+
+  seed.foreach ([this](PhysLocationAttr loc) { (void)addPlacement(loc, {}); });
+  seeded = true;
+}
 
 /// Assign an instance to a primitive. Return false if another instance is
 /// already placed at that location.
 LogicalResult PlacementDB::addPlacement(PhysLocationAttr loc,
                                         PlacedInstance inst) {
-  PlacedInstance &cell = placements[loc.getX()][loc.getY()][loc.getNum()]
-                                   [loc.getPrimitiveType().getValue()];
-  if (cell.op != nullptr)
+
+  Optional<PlacedInstance *> leaf = getLeaf(loc);
+  if (!leaf)
+    return inst.op->emitOpError("Could not apply placement. Invalid location");
+  PlacedInstance *cell = *leaf;
+  if (cell->op != nullptr)
     return inst.op->emitOpError("Could not apply placement ")
-           << loc << ". Position already occupied by " << cell.op << ".";
-  cell = inst;
+           << loc << ". Position already occupied by " << cell->op << ".";
+  *cell = inst;
   return success();
 }
 
@@ -102,6 +112,23 @@ PlacementDB::getInstanceAt(PhysLocationAttr loc) {
   return instF->getSecond();
 }
 
+Optional<PlacementDB::PlacedInstance *>
+PlacementDB::getLeaf(PhysLocationAttr loc) {
+  PrimitiveType primType = loc.getPrimitiveType().getValue();
+
+  DimNumMap &nums = placements[loc.getX()][loc.getY()];
+  if (!seeded)
+    return &nums[loc.getNum()][primType];
+
+  auto primitivesF = nums.find(loc.getNum());
+  if (primitivesF == nums.end())
+    return {};
+  auto primitives = primitivesF->second;
+  if (primitives.count(primType) == 0)
+    return {};
+  return &primitives[primType];
+}
+
 /// Walker for placements.
 void PlacementDB::walkPlacements(
     function_ref<void(PhysLocationAttr, PlacedInstance)> callback) {