Store transitioned JSArray maps in global context

src/ia32/macro-assembler-ia32.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 2150 matching lines @@
   // A variable occurring in such a scope should have slot type LOOKUP and
   // not CONTEXT.
   if (emit_debug_code()) {
     cmp(FieldOperand(dst, HeapObject::kMapOffset),
         isolate()->factory()->with_context_map());
     Check(not_equal, "Variable resolved to with context.");
   }
 }
 
 
+void MacroAssembler::LoadGlobalInitialConstructedArrayMap(
+    Register function_in, Register scratch, Register map_out) {
+  ASSERT(!function_in.is(map_out));
+  Label done;
+  mov(map_out, FieldOperand(function_in,
+                            JSFunction::kPrototypeOrInitialMapOffset));
+  if (!FLAG_smi_only_arrays) {
+    // Load the global or builtins object from the current context.
+    mov(scratch, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
+    mov(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset));
+
+    // Check that the function's map is same as the cached map.
+    cmp(map_out,
+        Operand(scratch,
+                Context::SlotOffset(Context::SMI_JS_ARRAY_MAP_INDEX)));
+    j(not_equal, &done);
+
+    // Use the cached transitioned map.
+    mov(map_out,
+        Operand(scratch,
+                Context::SlotOffset(Context::OBJECT_JS_ARRAY_MAP_INDEX)));
+  }
+  bind(&done);
+}
+
+
 void MacroAssembler::LoadGlobalFunction(int index, Register function) {
   // Load the global or builtins object from the current context.
   mov(function, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
   // Load the global context from the global or builtins object.
   mov(function, FieldOperand(function, GlobalObject::kGlobalContextOffset));
   // Load the function from the global context.
   mov(function, Operand(function, Context::SlotOffset(index)));
 }
 
 
@@ skipping 569 matching lines @@
     cmp(length, Operand(bitmap_scratch, MemoryChunk::kSizeOffset));
     Check(less_equal, "Live Bytes Count overflow chunk size");
   }
 
   bind(&done);
 }
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32