[wasm] Int64Lowering: changing to DFS.

test/unittests/compiler/int64-lowering-unittest.cc

Index: test/unittests/compiler/int64-lowering-unittest.cc
diff --git a/test/unittests/compiler/int64-lowering-unittest.cc b/test/unittests/compiler/int64-lowering-unittest.cc
index ad980ac3f60c1059ae2b3f3ba88643a1969d8e89..c81fd0ad11174e5eedf886b086d37ce9119b06b4 100644
--- a/test/unittests/compiler/int64-lowering-unittest.cc
+++ b/test/unittests/compiler/int64-lowering-unittest.cc
@@ -479,6 +479,24 @@ TEST_F(Int64LoweringTest, I64UConvertI32_2) {
 // kExprI64Clz:
 // kExprI64Ctz:
 // kExprI64Popcnt:
+
+TEST_F(Int64LoweringTest, Dfs) {
+  Node* common = Int64Constant(value(0));
+  LowerGraph(graph()->NewNode(machine()->Word64And(), common,
+                              graph()->NewNode(machine()->Word64And(), common,
+                                               Int64Constant(value(1)))),
+             MachineRepresentation::kWord64);
+
+  EXPECT_THAT(
+      graph()->end()->InputAt(1),
+      IsReturn2(IsWord32And(IsInt32Constant(low_word_value(0)),
+                            IsWord32And(IsInt32Constant(low_word_value(0)),
+                                        IsInt32Constant(low_word_value(1)))),
+                IsWord32And(IsInt32Constant(high_word_value(0)),
+                            IsWord32And(IsInt32Constant(high_word_value(0)),
+                                        IsInt32Constant(high_word_value(1)))),
+                start(), start()));
+}
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8