[turbofan] Some strength reduction on Smi/HeapObject checks.

test/unittests/compiler/simplified-operator-reducer-unittest.cc

Index: test/unittests/compiler/simplified-operator-reducer-unittest.cc
diff --git a/test/unittests/compiler/simplified-operator-reducer-unittest.cc b/test/unittests/compiler/simplified-operator-reducer-unittest.cc
index f90f1c053675ef431d626b509e5b0d6788337ef8..f4d8bac70449ea6c1a7deb8e83f74d7d78c62fdf 100644
--- a/test/unittests/compiler/simplified-operator-reducer-unittest.cc
+++ b/test/unittests/compiler/simplified-operator-reducer-unittest.cc
@@ -32,7 +32,8 @@ class SimplifiedOperatorReducerTest : public TypedGraphTest {
     JSOperatorBuilder javascript(zone());
     JSGraph jsgraph(isolate(), graph(), common(), &javascript, simplified(),
                     &machine);
-    SimplifiedOperatorReducer reducer(&jsgraph);
+    GraphReducer graph_reducer(zone(), graph());
+    SimplifiedOperatorReducer reducer(&graph_reducer, &jsgraph);
     return reducer.Reduce(node);
   }
 
@@ -343,7 +344,62 @@ TEST_F(SimplifiedOperatorReducerTest, TruncateTaggedToWord32WithConstant) {
 }
 
 // -----------------------------------------------------------------------------
-// TruncateTaggedToWord32
+// CheckTaggedPointer
+
+TEST_F(SimplifiedOperatorReducerTest, CheckTaggedPointerWithChangeBitToTagged) {
+  Node* param0 = Parameter(0);
+  Node* effect = graph()->start();
+  Node* control = graph()->start();
+  Node* value = graph()->NewNode(simplified()->ChangeBitToTagged(), param0);
+  Reduction reduction = Reduce(graph()->NewNode(
+      simplified()->CheckTaggedPointer(), value, effect, control));
+  ASSERT_TRUE(reduction.Changed());
+  EXPECT_EQ(value, reduction.replacement());
+}
+
+TEST_F(SimplifiedOperatorReducerTest, CheckTaggedPointerWithHeapConstant) {
+  Node* effect = graph()->start();
+  Node* control = graph()->start();
+  Handle<HeapObject> kHeapObjects[] = {
+      factory()->empty_string(), factory()->null_value(),
+      factory()->species_symbol(), factory()->undefined_value()};
+  TRACED_FOREACH(Handle<HeapObject>, object, kHeapObjects) {
+    Node* value = HeapConstant(object);
+    Reduction reduction = Reduce(graph()->NewNode(
+        simplified()->CheckTaggedPointer(), value, effect, control));
+    ASSERT_TRUE(reduction.Changed());
+    EXPECT_EQ(value, reduction.replacement());
+  }
+}
+
+// -----------------------------------------------------------------------------
+// CheckTaggedSigned
+
+TEST_F(SimplifiedOperatorReducerTest,
+       CheckTaggedSignedWithChangeInt31ToTaggedSigned) {
+  Node* param0 = Parameter(0);
+  Node* effect = graph()->start();
+  Node* control = graph()->start();
+  Node* value =
+      graph()->NewNode(simplified()->ChangeInt31ToTaggedSigned(), param0);
+  Reduction reduction = Reduce(graph()->NewNode(
+      simplified()->CheckTaggedSigned(), value, effect, control));
+  ASSERT_TRUE(reduction.Changed());
+  EXPECT_EQ(value, reduction.replacement());
+}
+
+TEST_F(SimplifiedOperatorReducerTest, CheckTaggedSignedWithNumberConstant) {
+  Node* effect = graph()->start();
+  Node* control = graph()->start();
+  Node* value = NumberConstant(1.0);
+  Reduction reduction = Reduce(graph()->NewNode(
+      simplified()->CheckTaggedSigned(), value, effect, control));
+  ASSERT_TRUE(reduction.Changed());
+  EXPECT_EQ(value, reduction.replacement());
+}
+
+// -----------------------------------------------------------------------------
+// ObjectIsSmi
 
 TEST_F(SimplifiedOperatorReducerTest, ObjectIsSmiWithChangeBitToTagged) {
   Node* param0 = Parameter(0);