Reland: "Use stability to only conditionally flush information from the CheckMaps table."

src/code-stubs-hydrogen.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 277 matching lines @@
 }
 
 
 template <>
 HValue* CodeStubGraphBuilder<ToNumberStub>::BuildCodeStub() {
   HValue* value = GetParameter(0);
 
   // Check if the parameter is already a SMI or heap number.
   IfBuilder if_number(this);
   if_number.If<HIsSmiAndBranch>(value);
-  if_number.OrIf<HCompareMap>(value, isolate()->factory()->heap_number_map());
+  if_number.OrIf<HCompareMap>(value, isolate()->factory()->heap_number_map(),
+                              top_info());
   if_number.Then();
 
   // Return the number.
   Push(value);
 
   if_number.Else();
 
   // Convert the parameter to number using the builtin.
   HValue* function = AddLoadJSBuiltin(Builtins::TO_NUMBER);
   Add<HPushArgument>(value);
@@ skipping 42 matching lines @@
 
   HObjectAccess access = HObjectAccess::ForAllocationSiteOffset(
       AllocationSite::kTransitionInfoOffset);
   HInstruction* boilerplate = Add<HLoadNamedField>(
       allocation_site, static_cast<HValue*>(NULL), access);
   HValue* push_value;
   if (mode == FastCloneShallowArrayStub::CLONE_ANY_ELEMENTS) {
     HValue* elements = AddLoadElements(boilerplate);
 
     IfBuilder if_fixed_cow(this);
-    if_fixed_cow.If<HCompareMap>(elements, factory->fixed_cow_array_map());
+    if_fixed_cow.If<HCompareMap>(elements, factory->fixed_cow_array_map(),
+                                 top_info());
     if_fixed_cow.Then();
     push_value = BuildCloneShallowArray(boilerplate,
                                         allocation_site,
                                         alloc_site_mode,
                                         FAST_ELEMENTS,
                                         0/*copy-on-write*/);
     environment()->Push(push_value);
     if_fixed_cow.Else();
 
     IfBuilder if_fixed(this);
-    if_fixed.If<HCompareMap>(elements, factory->fixed_array_map());
+    if_fixed.If<HCompareMap>(elements, factory->fixed_array_map(), top_info());
     if_fixed.Then();
     push_value = BuildCloneShallowArray(boilerplate,
                                         allocation_site,
                                         alloc_site_mode,
                                         FAST_ELEMENTS,
                                         length);
     environment()->Push(push_value);
     if_fixed.Else();
     push_value = BuildCloneShallowArray(boilerplate,
                                         allocation_site,
@@ skipping 1012 matching lines @@
   return BuildRegExpConstructResult(length, index, input);
 }
 
 
 Handle<Code> RegExpConstructResultStub::GenerateCode(Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 
 } }  // namespace v8::internal