emit premonomorphic ics for loads/stores in optimized code

src/ic/ic-compiler.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/v8.h"
 
 #include "src/ic/handler-compiler.h"
 #include "src/ic/ic-inl.h"
 #include "src/ic/ic-compiler.h"
 
@@ skipping 179 matching lines @@
       isolate->factory()->non_monomorphic_cache();
   int entry = cache->FindEntry(isolate, flags);
   if (entry != -1) return Handle<Code>(Code::cast(cache->ValueAt(entry)));
 
   PropertyICCompiler compiler(isolate, Code::LOAD_IC);
   Handle<Code> code;
   if (ic_state == UNINITIALIZED) {
     code = compiler.CompileLoadInitialize(flags);
   } else if (ic_state == PREMONOMORPHIC) {
     code = compiler.CompileLoadPreMonomorphic(flags);
+  } else if (ic_state == MEGAMORPHIC) {
+    code = compiler.CompileLoadMegamorphic(flags);
   } else {
     UNREACHABLE();
   }
   FillCache(isolate, code);
   return code;
 }
 
 
 Handle<Code> PropertyICCompiler::ComputeStore(Isolate* isolate,
                                               InlineCacheState ic_state,
@@ skipping 122 matching lines @@
 
 Handle<Code> PropertyICCompiler::CompileLoadPreMonomorphic(Code::Flags flags) {
   LoadIC::GeneratePreMonomorphic(masm());
   Handle<Code> code = GetCodeWithFlags(flags, "CompileLoadPreMonomorphic");
   PROFILE(isolate(),
           CodeCreateEvent(Logger::LOAD_PREMONOMORPHIC_TAG, *code, 0));
   return code;
 }
 
 
+Handle<Code> PropertyICCompiler::CompileLoadMegamorphic(Code::Flags flags) {
+  MegamorphicLoadStub stub(isolate(), LoadICState(extra_ic_state_));
+  auto code = stub.GetCode();
+  PROFILE(isolate(), CodeCreateEvent(Logger::LOAD_MEGAMORPHIC_TAG, *code, 0));
+  return code;
+}
+
+
 Handle<Code> PropertyICCompiler::CompileStoreInitialize(Code::Flags flags) {
   StoreIC::GenerateInitialize(masm());
   Handle<Code> code = GetCodeWithFlags(flags, "CompileStoreInitialize");
   PROFILE(isolate(), CodeCreateEvent(Logger::STORE_INITIALIZE_TAG, *code, 0));
   return code;
 }
 
 
 Handle<Code> PropertyICCompiler::CompileStorePreMonomorphic(Code::Flags flags) {
   StoreIC::GeneratePreMonomorphic(masm());
@@ skipping 108 matching lines @@
 
   TailCallBuiltin(masm(), Builtins::kKeyedStoreIC_Miss);
 
   return GetCode(kind(), Code::NORMAL, factory()->empty_string());
 }
 
 
 #undef __
 }
 }  // namespace v8::internal