[turbofan] Add Symbol feedback to Equal/StrictEqual.

src/compiler/effect-control-linearizer.cc

 // Copyright 2015 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/compiler/effect-control-linearizer.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/compiler-source-position-table.h"
 #include "src/compiler/js-graph.h"
@@ skipping 623 matching lines @@
       break;
     case IrOpcode::kCheckMaps:
       result = LowerCheckMaps(node, frame_state);
       break;
     case IrOpcode::kCheckNumber:
       result = LowerCheckNumber(node, frame_state);
       break;
     case IrOpcode::kCheckReceiver:
       result = LowerCheckReceiver(node, frame_state);
       break;
+    case IrOpcode::kCheckSymbol:
+      result = LowerCheckSymbol(node, frame_state);
+      break;
     case IrOpcode::kCheckString:
       result = LowerCheckString(node, frame_state);
       break;
     case IrOpcode::kCheckInternalizedString:
       result = LowerCheckInternalizedString(node, frame_state);
       break;
     case IrOpcode::kCheckIf:
       result = LowerCheckIf(node, frame_state);
       break;
     case IrOpcode::kCheckedInt32Add:
@@ skipping 639 matching lines @@
       __ LoadField(AccessBuilder::ForMapInstanceType(), value_map);
 
   STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
   Node* check = __ Uint32LessThanOrEqual(
       __ Uint32Constant(FIRST_JS_RECEIVER_TYPE), value_instance_type);
   __ DeoptimizeUnless(DeoptimizeReason::kNotAJavaScriptObject, check,
                       frame_state);
   return value;
 }
 
+Node* EffectControlLinearizer::LowerCheckSymbol(Node* node, Node* frame_state) {
+  Node* value = node->InputAt(0);
+
+  Node* value_map = __ LoadField(AccessBuilder::ForMap(), value);
+
+  Node* check =
+      __ WordEqual(value_map, __ HeapConstant(factory()->symbol_map()));
+  __ DeoptimizeUnless(DeoptimizeReason::kNotASymbol, check, frame_state);
+  return value;
+}
+
 Node* EffectControlLinearizer::LowerCheckString(Node* node, Node* frame_state) {
   Node* value = node->InputAt(0);
 
   Node* value_map = __ LoadField(AccessBuilder::ForMap(), value);
   Node* value_instance_type =
       __ LoadField(AccessBuilder::ForMapInstanceType(), value_map);
 
   Node* check = __ Uint32LessThan(value_instance_type,
                                   __ Uint32Constant(FIRST_NONSTRING_TYPE));
   __ DeoptimizeUnless(DeoptimizeReason::kWrongInstanceType, check, frame_state);
@@ skipping 1680 matching lines @@
   return isolate()->factory();
 }
 
 Isolate* EffectControlLinearizer::isolate() const {
   return jsgraph()->isolate();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8