Introduce extra IC state to record additional feedback from IC-s.

src/x64/stub-cache-x64.cc

Index: src/x64/stub-cache-x64.cc
diff --git a/src/x64/stub-cache-x64.cc b/src/x64/stub-cache-x64.cc
index 57cba142128c3f3d36adc1ad2d0de1a058fcf54f..05eaf0b348e0ba0955f3055c37d1ab2551123d3d 100644
--- a/src/x64/stub-cache-x64.cc
+++ b/src/x64/stub-cache-x64.cc
@@ -1327,8 +1327,8 @@ void CallStubCompiler::GenerateLoadFunctionFromCell(JSGlobalPropertyCell* cell,
 
 
 MaybeObject* CallStubCompiler::GenerateMissBranch() {
-  MaybeObject* maybe_obj =
-      StubCache::ComputeCallMiss(arguments().immediate(), kind_);
+  MaybeObject* maybe_obj = StubCache::ComputeCallMiss(arguments().immediate(),
+                                                      kind_);
   Object* obj;
   if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   __ Jump(Handle<Code>(Code::cast(obj)), RelocInfo::CODE_TARGET);
@@ -1660,9 +1660,15 @@ MaybeObject* CallStubCompiler::CompileStringCharCodeAtCall(
   const int argc = arguments().immediate();
 
   Label miss;
+  Label name_miss;
   Label index_out_of_range;
+  Label* index_out_of_range_label = &index_out_of_range;
 
-  GenerateNameCheck(name, &miss);
+  if (kind_ == Code::CALL_IC && extra_ic_state_ == DEFAULT_STRING_STUB) {
+    index_out_of_range_label = &miss;
+  }
+
+  GenerateNameCheck(name, &name_miss);
 
   // Check that the maps starting from the prototype haven't changed.
   GenerateDirectLoadGlobalFunctionPrototype(masm(),
@@ -1690,7 +1696,7 @@ MaybeObject* CallStubCompiler::CompileStringCharCodeAtCall(
                                                    result,
                                                    &miss,  // When not a string.
                                                    &miss,  // When not a number.
-                                                   &index_out_of_range,
+                                                   index_out_of_range_label,
                                                    STRING_INDEX_IS_NUMBER);
   char_code_at_generator.GenerateFast(masm());
   __ ret((argc + 1) * kPointerSize);
@@ -1698,11 +1704,16 @@ MaybeObject* CallStubCompiler::CompileStringCharCodeAtCall(
   StubRuntimeCallHelper call_helper;
   char_code_at_generator.GenerateSlow(masm(), call_helper);
 
-  __ bind(&index_out_of_range);
-  __ LoadRoot(rax, Heap::kNanValueRootIndex);
-  __ ret((argc + 1) * kPointerSize);
+  if (index_out_of_range.is_linked()) {
+    __ bind(&index_out_of_range);
+    __ LoadRoot(rax, Heap::kNanValueRootIndex);
+    __ ret((argc + 1) * kPointerSize);
+  }
 
   __ bind(&miss);
+  // Restore function name in rcx.
+  __ Move(rcx, Handle<String>(name));
+  __ bind(&name_miss);
   Object* obj;
   { MaybeObject* maybe_obj = GenerateMissBranch();
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
@@ -1733,9 +1744,15 @@ MaybeObject* CallStubCompiler::CompileStringCharAtCall(
   const int argc = arguments().immediate();
 
   Label miss;
+  Label name_miss;
   Label index_out_of_range;
+  Label* index_out_of_range_label = &index_out_of_range;
 
-  GenerateNameCheck(name, &miss);
+  if (kind_ == Code::CALL_IC && extra_ic_state_ == DEFAULT_STRING_STUB) {
+    index_out_of_range_label = &miss;
+  }
+
+  GenerateNameCheck(name, &name_miss);
 
   // Check that the maps starting from the prototype haven't changed.
   GenerateDirectLoadGlobalFunctionPrototype(masm(),
@@ -1765,7 +1782,7 @@ MaybeObject* CallStubCompiler::CompileStringCharAtCall(
                                           result,
                                           &miss,  // When not a string.
                                           &miss,  // When not a number.
-                                          &index_out_of_range,
+                                          index_out_of_range_label,
                                           STRING_INDEX_IS_NUMBER);
   char_at_generator.GenerateFast(masm());
   __ ret((argc + 1) * kPointerSize);
@@ -1773,11 +1790,16 @@ MaybeObject* CallStubCompiler::CompileStringCharAtCall(
   StubRuntimeCallHelper call_helper;
   char_at_generator.GenerateSlow(masm(), call_helper);
 
-  __ bind(&index_out_of_range);
-  __ LoadRoot(rax, Heap::kEmptyStringRootIndex);
-  __ ret((argc + 1) * kPointerSize);
+  if (index_out_of_range.is_linked()) {
+    __ bind(&index_out_of_range);
+    __ LoadRoot(rax, Heap::kEmptyStringRootIndex);
+    __ ret((argc + 1) * kPointerSize);
+  }
 
   __ bind(&miss);
+  // Restore function name in rcx.
+  __ Move(rcx, Handle<String>(name));
+  __ bind(&name_miss);
   Object* obj;
   { MaybeObject* maybe_obj = GenerateMissBranch();
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;