[OM] Fix tuple_get operation in OMEvaluator (llvm#8322)

Author: unlsycn

lib/Dialect/OM/Evaluator/Evaluator.cpp

@@ -171,6 +171,9 @@ FailureOr<evaluator::EvaluatorValuePtr> circt::om::Evaluator::getOrCreateValue(
                       ObjectFieldOp>([&](auto op) {
                   return getPartiallyEvaluatedValue(op.getType(), loc);
                 })
+                .Case<TupleGetOp>([&](auto op) {
+                  return evaluateTupleGet(op, actualParams, loc);
+                })
                 .Case<ObjectOp>([&](auto op) {
                   return getPartiallyEvaluatedValue(op.getType(), op.getLoc());
                 })

unittests/Dialect/OM/Evaluator/EvaluatorTests.cpp

@@ -1189,6 +1189,40 @@ TEST(EvaluatorTests, ListConcatField) {
                    .getValue());
 }
 
+TEST(EvaluatorTests, TupleGet) {
+  StringRef mod = "om.class @Tuple() -> (val: !om.string) {"
+                  "  %int = om.constant 1 : i1"
+                  "  %str = om.constant \"foo\" : !om.string"
+                  "  %tuple = om.tuple_create %int, %str  : i1, !om.string"
+                  "  %val = om.tuple_get %tuple[1]  : tuple<i1, !om.string>"
+                  "  om.class.fields %val : !om.string"
+                  "}";
+
+  DialectRegistry registry;
+  registry.insert<OMDialect>();
+
+  MLIRContext context(registry);
+  context.getOrLoadDialect<OMDialect>();
+
+  OwningOpRef<ModuleOp> owning =
+      parseSourceString<ModuleOp>(mod, ParserConfig(&context));
+
+  Evaluator evaluator(owning.release());
+
+  auto result = evaluator.instantiate(StringAttr::get(&context, "Tuple"), {});
+
+  ASSERT_TRUE(succeeded(result));
+
+  auto fieldValue = llvm::cast<evaluator::ObjectValue>(result.value().get())
+                        ->getField("val")
+                        .value();
+
+  ASSERT_EQ("foo", llvm::cast<evaluator::AttributeValue>(fieldValue.get())
+                       ->getAs<StringAttr>()
+                       .getValue()
+                       .str());
+}
+
 TEST(EvaluatorTests, NestedReferenceValue) {
   StringRef mod =
       "om.class @Empty() {"