[date] Refactor the %_DateField intrinsic to be optimizable.

src/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 11910 matching lines @@
   DCHECK(call->arguments()->length() == 1);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   HValue* value = Pop();
   HInstruction* result = Add<HLoadNamedField>(
       value, nullptr,
       HObjectAccess::ForObservableJSObjectOffset(JSValue::kValueOffset));
   return ast_context()->ReturnInstruction(result, call->id());
 }
 
 
+void HOptimizedGraphBuilder::GenerateThrowIfNotADate(CallRuntime* call) {
+  DCHECK_EQ(1, call->arguments()->length());
+  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
+  HValue* obj = Pop();
+  BuildCheckHeapObject(obj);
+  HCheckInstanceType* check =
+      New<HCheckInstanceType>(obj, HCheckInstanceType::IS_JS_DATE);
+  return ast_context()->ReturnInstruction(check, call->id());
+}
+
+
 void HOptimizedGraphBuilder::GenerateDateField(CallRuntime* call) {
   DCHECK(call->arguments()->length() == 2);
   DCHECK_NOT_NULL(call->arguments()->at(1)->AsLiteral());
   Smi* index = Smi::cast(*(call->arguments()->at(1)->AsLiteral()->value()));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   HValue* date = Pop();
   HDateField* result = New<HDateField>(date, index);
   return ast_context()->ReturnInstruction(result, call->id());
 }
 
@@ skipping 1215 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8