Store transitioned JSArray maps in global context

src/arm/macro-assembler-arm.cc

Index: src/arm/macro-assembler-arm.cc
diff --git a/src/arm/macro-assembler-arm.cc b/src/arm/macro-assembler-arm.cc
index 9894ff202e6d1b87e98b20ce60268ff336ae3273..1832db411a656f92aecfd53d4b7047dd90765e59 100644
--- a/src/arm/macro-assembler-arm.cc
+++ b/src/arm/macro-assembler-arm.cc
@@ -2879,6 +2879,32 @@ void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
 }
 
 
+void MacroAssembler::LoadGlobalInitialConstructedArrayMap(
+    Register function_in, Register scratch, Register map_out) {
+  ASSERT(!function_in.is(map_out));
+  Label done;
+  ldr(map_out, FieldMemOperand(function_in,
+                               JSFunction::kPrototypeOrInitialMapOffset));
+  if (!FLAG_smi_only_arrays) {
+    // Load the global or builtins object from the current context.
+    ldr(scratch, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
+    ldr(scratch, FieldMemOperand(scratch, GlobalObject::kGlobalContextOffset));
+
+    // Check that the function's map is same as the cached map.
+    ldr(ip, MemOperand(
+        scratch, Context::SlotOffset(Context::SMI_JS_ARRAY_MAP_INDEX)));
+    cmp(map_out, ip);
+    b(ne, &done);
+
+    // Use the cached transitioned map.
+    ldr(map_out,
+        MemOperand(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.
   ldr(function, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));