MIPS: Fix return-value from Array.push stub when pushing non-SMI value

src/mips/stub-cache-mips.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 1785 matching lines @@
 
       __ bind(&check_double);
 
       // Check that the elements are in fast mode and writable.
       __ CheckMap(elements,
                   a0,
                   Heap::kFixedDoubleArrayMapRootIndex,
                   &call_builtin,
                   DONT_DO_SMI_CHECK);
 
-      // Get the array's length into r0 and calculate new length.
-      __ lw(a0, FieldMemOperand(receiver, JSArray::kLengthOffset));
+      // Get the array's length into v0 and calculate new length.
+      __ lw(v0, FieldMemOperand(receiver, JSArray::kLengthOffset));
       STATIC_ASSERT(kSmiTagSize == 1);
       STATIC_ASSERT(kSmiTag == 0);
-      __ Addu(a0, a0, Operand(Smi::FromInt(argc)));
+      __ Addu(v0, v0, Operand(Smi::FromInt(argc)));
 
       // Get the elements' length.
       __ lw(t0, FieldMemOperand(elements, FixedArray::kLengthOffset));
 
       // Check if we could survive without allocation.
-      __ Branch(&call_builtin, gt, a0, Operand(t0));
+      __ Branch(&call_builtin, gt, v0, Operand(t0));
 
       __ lw(t0, MemOperand(sp, (argc - 1) * kPointerSize));
       __ StoreNumberToDoubleElements(
-          t0, a0, elements, a3, t1, a2, t5,
+          t0, v0, elements, a3, t1, a2, t5,
           &call_builtin, argc * kDoubleSize);
 
       // Save new length.
-      __ sw(a0, FieldMemOperand(receiver, JSArray::kLengthOffset));
+      __ sw(v0, FieldMemOperand(receiver, JSArray::kLengthOffset));
 
       // Check for a smi.
       __ DropAndRet(argc + 1);
 
       __ bind(&with_write_barrier);
 
       __ lw(a3, FieldMemOperand(receiver, HeapObject::kMapOffset));
 
       if (FLAG_smi_only_arrays  && !FLAG_trace_elements_transitions) {
         Label fast_object, not_fast_object;
@@ skipping 1376 matching lines @@
   // -----------------------------------
   TailCallBuiltin(masm, Builtins::kKeyedLoadIC_MissForceGeneric);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS