[turbofan] Optimize strict equality of unique values.

test/unittests/compiler/js-typed-lowering-unittest.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/js-typed-lowering.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 418 matching lines @@
 }
 
 
 // -----------------------------------------------------------------------------
 // JSStrictEqual
 
 
 TEST_F(JSTypedLoweringTest, JSStrictEqualWithTheHole) {
   Node* const the_hole = HeapConstant(factory()->the_hole_value());
   Node* const context = UndefinedConstant();
-  Node* const effect = graph()->start();
-  Node* const control = graph()->start();
   TRACED_FOREACH(Type*, type, kJSTypes) {
     Node* const lhs = Parameter(type);
-    Reduction r = Reduce(graph()->NewNode(javascript()->StrictEqual(), lhs,
-                                          the_hole, context, effect, control));
+    Reduction r = Reduce(
+        graph()->NewNode(javascript()->StrictEqual(), lhs, the_hole, context));
     ASSERT_TRUE(r.Changed());
     EXPECT_THAT(r.replacement(), IsFalseConstant());
   }
 }
 
 
+TEST_F(JSTypedLoweringTest, JSStrictEqualWithUnique) {
+  Node* const lhs = Parameter(Type::Unique(), 0);
+  Node* const rhs = Parameter(Type::Unique(), 1);
+  Node* const context = Parameter(Type::Any(), 2);
+  Reduction r =
+      Reduce(graph()->NewNode(javascript()->StrictEqual(), lhs, rhs, context));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_THAT(r.replacement(), IsReferenceEqual(Type::Unique(), lhs, rhs));
+}
+
+
 // -----------------------------------------------------------------------------
 // JSShiftLeft
 
 
 TEST_F(JSTypedLoweringTest, JSShiftLeftWithSigned32AndConstant) {
   Node* const lhs = Parameter(Type::Signed32());
   Node* const context = UndefinedConstant();
   Node* const effect = graph()->start();
   Node* const control = graph()->start();
   TRACED_FORRANGE(double, rhs, 0, 31) {
@@ skipping 525 matching lines @@
   EXPECT_THAT(r.replacement(),
               IsFinish(IsAllocate(IsNumberConstant(Context::SizeFor(
                                       Context::MIN_CONTEXT_SLOTS)),
                                   effect, control),
                        _));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8