[Isolates] Merge from bleeding_edge to isolates, revisions 6100-6300.

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 6941)
+++ src/heap.cc	(working copy)
@@ -1997,6 +1997,13 @@
   }
   set_the_hole_value(obj);
 
+  { MaybeObject* maybe_obj = CreateOddball("arguments_marker",
+                                           Smi::FromInt(-4),
+                                           Oddball::kArgumentMarker);
+    if (!maybe_obj->ToObject(&obj)) return false;
+  }
+  set_arguments_marker(obj);
+
   { MaybeObject* maybe_obj = CreateOddball("no_interceptor_result_sentinel",
                                            Smi::FromInt(-2),
                                            Oddball::kOther);
@@ -2540,20 +2547,10 @@
   }
 
   // For small strings we check whether the resource contains only
-  // ascii characters.  If yes, we use a different string map.
-  bool is_ascii = true;
-  if (length >= static_cast<size_t>(String::kMinNonFlatLength)) {
-    is_ascii = false;
-  } else {
-    const uc16* data = resource->data();
-    for (size_t i = 0; i < length; i++) {
-      if (data[i] > String::kMaxAsciiCharCode) {
-        is_ascii = false;
-        break;
-      }
-    }
-  }
-
+  // ASCII characters.  If yes, we use a different string map.
+  static const size_t kAsciiCheckLengthLimit = 32;
+  bool is_ascii = length <= kAsciiCheckLengthLimit &&
+      String::IsAscii(resource->data(), static_cast<int>(length));
   Map* map = is_ascii ?
       external_string_with_ascii_data_map() : external_string_map();
   Object* result;
@@ -2720,6 +2717,9 @@
   code->set_instruction_size(desc.instr_size);
   code->set_relocation_info(ByteArray::cast(reloc_info));
   code->set_flags(flags);
+  if (code->is_call_stub() || code->is_keyed_call_stub()) {
+    code->set_check_type(RECEIVER_MAP_CHECK);
+  }
   code->set_deoptimization_data(empty_fixed_array());
   // Allow self references to created code object by patching the handle to
   // point to the newly allocated Code object.
@@ -3335,11 +3335,8 @@
 MaybeObject* Heap::AllocateStringFromTwoByte(Vector<const uc16> string,
                                              PretenureFlag pretenure) {
   // Check if the string is an ASCII string.
-  int i = 0;
-  while (i < string.length() && string[i] <= String::kMaxAsciiCharCode) i++;
-
   MaybeObject* maybe_result;
-  if (i == string.length()) {  // It's an ASCII string.
+  if (String::IsAscii(string.start(), string.length())) {
     maybe_result = AllocateRawAsciiString(string.length(), pretenure);
   } else {  // It's not an ASCII string.
     maybe_result = AllocateRawTwoByteString(string.length(), pretenure);
@@ -4042,6 +4039,36 @@
 }
 
 
+MaybeObject* Heap::LookupAsciiSymbol(Vector<const char> string) {
+  Object* symbol = NULL;
+  Object* new_table;
+  { MaybeObject* maybe_new_table =
+        symbol_table()->LookupAsciiSymbol(string, &symbol);
+    if (!maybe_new_table->ToObject(&new_table)) return maybe_new_table;
+  }
+  // Can't use set_symbol_table because SymbolTable::cast knows that
+  // SymbolTable is a singleton and checks for identity.
+  roots_[kSymbolTableRootIndex] = new_table;
+  ASSERT(symbol != NULL);
+  return symbol;
+}
+
+
+MaybeObject* Heap::LookupTwoByteSymbol(Vector<const uc16> string) {
+  Object* symbol = NULL;
+  Object* new_table;
+  { MaybeObject* maybe_new_table =
+        symbol_table()->LookupTwoByteSymbol(string, &symbol);
+    if (!maybe_new_table->ToObject(&new_table)) return maybe_new_table;
+  }
+  // Can't use set_symbol_table because SymbolTable::cast knows that
+  // SymbolTable is a singleton and checks for identity.
+  roots_[kSymbolTableRootIndex] = new_table;
+  ASSERT(symbol != NULL);
+  return symbol;
+}
+
+
 MaybeObject* Heap::LookupSymbol(String* string) {
   if (string->IsSymbol()) return string;
   Object* symbol = NULL;
@@ -5220,7 +5247,7 @@
       obj->SetMark();
     }
     UnmarkingVisitor visitor;
-    HEAP->IterateRoots(&visitor, VISIT_ONLY_STRONG);
+    HEAP->IterateRoots(&visitor, VISIT_ALL);
     while (visitor.can_process())
       visitor.ProcessNext();
   }