Becuase of cross-context calls, hydrogen-based Array constructor needs to ensure

src/arm/code-stubs-arm.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 120 matching lines @@
       ExternalReference(IC_Utility(IC::kCompareNilIC_Miss), isolate);
 }
 
 
 static void InitializeArrayConstructorDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor,
     int constant_stack_parameter_count) {
   // register state
   // r0 -- number of arguments
+  // r1 -- function
   // r2 -- type info cell with elements kind
-  static Register registers[] = { r2 };
-  descriptor->register_param_count_ = 1;
+  static Register registers[] = { r1, r2 };
+  descriptor->register_param_count_ = 2;
   if (constant_stack_parameter_count != 0) {
     // stack param count needs (constructor pointer, and single argument)
     descriptor->stack_parameter_count_ = &r0;
   }
   descriptor->hint_stack_parameter_count_ = constant_stack_parameter_count;
   descriptor->register_params_ = registers;
   descriptor->function_mode_ = JS_FUNCTION_STUB_MODE;
   descriptor->deoptimization_handler_ =
       FUNCTION_ADDR(ArrayConstructor_StubFailure);
 }
@@ skipping 7200 matching lines @@
     __ cmp(r3, Operand(global_property_cell_map));
     __ Assert(eq, "Expected property cell in register ebx");
     __ bind(&okay_here);
   }
 
   if (FLAG_optimize_constructed_arrays) {
     Label no_info, switch_ready;
     // Get the elements kind and case on that.
     __ cmp(r2, Operand(undefined_sentinel));
     __ b(eq, &no_info);
-    __ ldr(r3, FieldMemOperand(r2, kPointerSize));
-
-    // There is no info if the call site went megamorphic either
-    // TODO(mvstanton): Really? I thought if it was the array function that
-    // the cell wouldn't get stamped as megamorphic.
-    __ cmp(r3,
-           Operand(TypeFeedbackCells::MegamorphicSentinel(masm->isolate())));
-    __ b(eq, &no_info);
+    __ ldr(r3, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
+    __ JumpIfNotSmi(r3, &no_info);
     __ SmiUntag(r3);
     __ jmp(&switch_ready);
     __ bind(&no_info);
     __ mov(r3, Operand(GetInitialFastElementsKind()));
     __ bind(&switch_ready);
 
     if (argument_count_ == ANY) {
       Label not_zero_case, not_one_case;
       __ tst(r0, r0);
       __ b(ne, &not_zero_case);
@@ skipping 28 matching lines @@
      __ Jump(generic_construct_stub, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM