Continued fix for 351257. Reusing the feedback vector is too complex.

src/x64/full-codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 101 matching lines @@
 //   o rbp: our caller's frame pointer
 //   o rsp: stack pointer (pointing to return address)
 //
 // The function builds a JS frame.  Please see JavaScriptFrameConstants in
 // frames-x64.h for its layout.
 void FullCodeGenerator::Generate() {
   CompilationInfo* info = info_;
   handler_table_ =
       isolate()->factory()->NewFixedArray(function()->handler_count(), TENURED);
 
-  InitializeFeedbackVector();
-
   profiling_counter_ = isolate()->factory()->NewCell(
       Handle<Smi>(Smi::FromInt(FLAG_interrupt_budget), isolate()));
   SetFunctionPosition(function());
   Comment cmnt(masm_, "[ function compiled by full code generator");
 
   ProfileEntryHookStub::MaybeCallEntryHook(masm_);
 
 #ifdef DEBUG
   if (strlen(FLAG_stop_at) > 0 &&
       info->function()->name()->IsUtf8EqualTo(CStrVector(FLAG_stop_at))) {
@@ skipping 986 matching lines @@
   __ jmp(&loop);
 
   __ bind(&no_descriptors);
   __ addq(rsp, Immediate(kPointerSize));
   __ jmp(&exit);
 
   // We got a fixed array in register rax. Iterate through that.
   Label non_proxy;
   __ bind(&fixed_array);
 
-  Handle<Object> feedback = Handle<Object>(
-      Smi::FromInt(TypeFeedbackInfo::kForInFastCaseMarker),
-      isolate());
-  StoreFeedbackVectorSlot(slot, feedback);
-
   // No need for a write barrier, we are storing a Smi in the feedback vector.
   __ Move(rbx, FeedbackVector());
   __ Move(FieldOperand(rbx, FixedArray::OffsetOfElementAt(slot)),
-          Smi::FromInt(TypeFeedbackInfo::kForInSlowCaseMarker));
+          TypeFeedbackInfo::MegamorphicSentinel(isolate()));
   __ Move(rbx, Smi::FromInt(1));  // Smi indicates slow check
   __ movp(rcx, Operand(rsp, 0 * kPointerSize));  // Get enumerated object
   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   __ CmpObjectType(rcx, LAST_JS_PROXY_TYPE, rcx);
   __ j(above, &non_proxy);
   __ Move(rbx, Smi::FromInt(0));  // Zero indicates proxy
   __ bind(&non_proxy);
   __ push(rbx);  // Smi
   __ push(rax);  // Array
   __ movp(rax, FieldOperand(rax, FixedArray::kLengthOffset));
@@ skipping 1492 matching lines @@
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
   { PreservePositionScope scope(masm()->positions_recorder());
     for (int i = 0; i < arg_count; i++) {
       VisitForStackValue(args->at(i));
     }
   }
   // Record source position for debugger.
   SetSourcePosition(expr->position());
 
-  Handle<Object> uninitialized =
-      TypeFeedbackInfo::UninitializedSentinel(isolate());
-  StoreFeedbackVectorSlot(expr->CallFeedbackSlot(), uninitialized);
   __ Move(rbx, FeedbackVector());
   __ Move(rdx, Smi::FromInt(expr->CallFeedbackSlot()));
 
   // Record call targets in unoptimized code.
   CallFunctionStub stub(arg_count, RECORD_CALL_TARGET);
   __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
   __ CallStub(&stub);
   RecordJSReturnSite(expr);
   // Restore context register.
   __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
@@ skipping 157 matching lines @@
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
   SetSourcePosition(expr->position());
 
   // Load function and argument count into rdi and rax.
   __ Set(rax, arg_count);
   __ movp(rdi, Operand(rsp, arg_count * kPointerSize));
 
   // Record call targets in unoptimized code, but not in the snapshot.
-  Handle<Object> uninitialized =
-      TypeFeedbackInfo::UninitializedSentinel(isolate());
-  StoreFeedbackVectorSlot(expr->CallNewFeedbackSlot(), uninitialized);
   __ Move(rbx, FeedbackVector());
   __ Move(rdx, Smi::FromInt(expr->CallNewFeedbackSlot()));
 
   CallConstructStub stub(RECORD_CALL_TARGET);
   __ Call(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL);
   PrepareForBailoutForId(expr->ReturnId(), TOS_REG);
   context()->Plug(rax);
 }
 
 
@@ skipping 2063 matching lines @@
   ASSERT_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64