[OM] Add om.map_create op (#5870)

This PR adds om.map_create op for om.map object creation which takes a variadic length of operands whose type is a same tuple.

include/circt/Dialect/OM/OMOps.td

@@ -261,4 +261,28 @@ def TupleGetOp : OMOp<"tuple_get", [Pure, InferTypeOpInterface]> {
    }];
 }
 
+def MapKeyValuePair: Type<CPred<"::circt::om::isMapKeyValuePairType($_self)">,
+                        "a pair whose first element is an attribute",
+                        "::mlir::TupleType">;
+
+def MapCreateOp : OMOp<"map_create", [Pure, SameTypeOperands]> {
+  let summary = "Create a map";
+  let description = [{
+    Creates a map from a sequence of inputs.
+
+    ```
+    %map = om.map_create %e1, %e2 : !om.string, i8
+    ```
+    where `%e1` and `e2` have !om.tuple<!om.string, i8> and
+    `%map` has `!om.map<!om.string, i8>` type.
+  }];
+
+  let arguments = (ins Variadic<MapKeyValuePair>:$inputs);
+  let results = (outs
+    MapType:$result
+  );
+
+  let hasCustomAssemblyFormat = true;
+}
+
 #endif // CIRCT_DIALECT_OM_OMOPS_TD

include/circt/Dialect/OM/OMTypes.h

@@ -16,6 +16,12 @@
 #include "mlir/IR/BuiltinAttributes.h"
 #include "mlir/IR/Types.h"
 
+namespace circt::om {
+// Return true if the type is a pair whose first element is either string or
+// integer.
+bool isMapKeyValuePairType(mlir::Type);
+} // namespace circt::om
+
 #define GET_TYPEDEF_CLASSES
 #include "circt/Dialect/OM/OMTypes.h.inc"
 

lib/Dialect/OM/OMOps.cpp

@@ -421,6 +421,38 @@ LogicalResult TupleGetOp::inferReturnTypes(
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// MapCreateOp
+//===----------------------------------------------------------------------===//
+
+void circt::om::MapCreateOp::print(OpAsmPrinter &p) {
+  p << " ";
+  p.printOperands(getInputs());
+  p.printOptionalAttrDict((*this)->getAttrs());
+  p << " : " << getType().cast<circt::om::MapType>().getKeyType() << ", "
+    << getType().cast<circt::om::MapType>().getValueType();
+}
+
+ParseResult circt::om::MapCreateOp::parse(OpAsmParser &parser,
+                                          OperationState &result) {
+  llvm::SmallVector<OpAsmParser::UnresolvedOperand, 16> operands;
+  Type elementType, valueType;
+
+  if (parser.parseOperandList(operands) ||
+      parser.parseOptionalAttrDict(result.attributes) || parser.parseColon() ||
+      parser.parseType(elementType) || parser.parseComma() ||
+      parser.parseType(valueType))
+    return failure();
+  result.addTypes({circt::om::MapType::get(elementType, valueType)});
+  auto operandType =
+      mlir::TupleType::get(valueType.getContext(), {elementType, valueType});
+
+  for (auto operand : operands)
+    if (parser.resolveOperand(operand, operandType, result.operands))
+      return failure();
+  return success();
+}
+
 //===----------------------------------------------------------------------===//
 // TableGen generated logic.
 //===----------------------------------------------------------------------===//

lib/Dialect/OM/OMTypes.cpp

@@ -35,3 +35,9 @@ circt::om::MapType::verify(llvm::function_ref<mlir::InFlightDiagnostic()> diag,
                   << keyType;
   return mlir::success();
 }
+
+bool circt::om::isMapKeyValuePairType(mlir::Type type) {
+  auto tuple = llvm::dyn_cast<mlir::TupleType>(type);
+  return tuple && tuple.getTypes().size() == 2 &&
+         llvm::isa<om::StringType, mlir::IntegerType>(tuple.getTypes().front());
+}

test/Dialect/OM/round-trip.mlir

@@ -191,3 +191,11 @@ om.class @MapConstant() {
   // CHECK: om.class.field @map_i64, %[[const1]] : !om.map<!om.string, i64>
   om.class.field @map_i64, %0 : !om.map<!om.string, i64>
 }
+
+// CHECK-LABEL: @MapCreate
+om.class @MapCreate(%e1: tuple<!om.string, !om.class.type<@Empty>>, %e2: tuple<!om.string, !om.class.type<@Empty>>) {
+  // CHECK: %[[map:.+]] = om.map_create %e1, %e2 : !om.string, !om.class.type<@Empty>
+  %map = om.map_create %e1, %e2 : !om.string, !om.class.type<@Empty>
+  // CHECK-NEXT: om.class.field @map_field, %[[map]] : !om.map<!om.string, !om.class.type<@Empty>>
+  om.class.field @map_field, %map : !om.map<!om.string, !om.class.type<@Empty>>
+}