Revert broken ArrayPop changes

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 1567 matching lines @@
                            index.translate(holder), Representation::Tagged());
   GenerateJumpFunction(object, a1, &miss);
 
   HandlerFrontendFooter(&miss);
 
   // Return the generated code.
   return GetCode(Code::FAST, name);
 }
 
 
+Handle<Code> CallStubCompiler::CompileArrayPopCall(
+    Handle<Object> object,
+    Handle<JSObject> holder,
+    Handle<Cell> cell,
+    Handle<JSFunction> function,
+    Handle<String> name,
+    Code::StubType type) {
+  // If object is not an array or is observed or sealed, bail out to regular
+  // call.
+  if (!object->IsJSArray() ||
+      !cell.is_null() ||
+      Handle<JSArray>::cast(object)->map()->is_observed() ||
+      !Handle<JSArray>::cast(object)->map()->is_extensible()) {
+    return Handle<Code>::null();
+  }
+
+  Label miss, return_undefined, call_builtin;
+  Register receiver = a0;
+  Register scratch = a1;
+  Register elements = a3;
+  HandlerFrontendHeader(object, holder, name, RECEIVER_MAP_CHECK, &miss);
+
+  // Get the elements array of the object.
+  __ lw(elements, FieldMemOperand(receiver, JSArray::kElementsOffset));
+
+  // Check that the elements are in fast mode and writable.
+  __ CheckMap(elements,
+              scratch,
+              Heap::kFixedArrayMapRootIndex,
+              &call_builtin,
+              DONT_DO_SMI_CHECK);
+
+  // Get the array's length into t0 and calculate new length.
+  __ lw(t0, FieldMemOperand(receiver, JSArray::kLengthOffset));
+  __ Subu(t0, t0, Operand(Smi::FromInt(1)));
+  __ Branch(&return_undefined, lt, t0, Operand(zero_reg));
+
+  // Get the last element.
+  __ LoadRoot(t2, Heap::kTheHoleValueRootIndex);
+  STATIC_ASSERT(kSmiTagSize == 1);
+  STATIC_ASSERT(kSmiTag == 0);
+  // We can't address the last element in one operation. Compute the more
+  // expensive shift first, and use an offset later on.
+  __ sll(t1, t0, kPointerSizeLog2 - kSmiTagSize);
+  __ Addu(elements, elements, t1);
+  __ lw(scratch, FieldMemOperand(elements, FixedArray::kHeaderSize));
+  __ Branch(&call_builtin, eq, scratch, Operand(t2));
+
+  // Set the array's length.
+  __ sw(t0, FieldMemOperand(receiver, JSArray::kLengthOffset));
+
+  // Fill with the hole.
+  __ sw(t2, FieldMemOperand(elements, FixedArray::kHeaderSize));
+  const int argc = arguments().immediate();
+  __ mov(v0, scratch);
+  __ DropAndRet(argc + 1);
+
+  __ bind(&return_undefined);
+  __ LoadRoot(v0, Heap::kUndefinedValueRootIndex);
+  __ DropAndRet(argc + 1);
+
+  __ bind(&call_builtin);
+  __ TailCallExternalReference(
+      ExternalReference(Builtins::c_ArrayPop, isolate()), argc + 1, 1);
+
+  HandlerFrontendFooter(&miss);
+
+  // Return the generated code.
+  return GetCode(type, name);
+}
+
+
 Handle<Code> CallStubCompiler::CompileFastApiCall(
     const CallOptimization& optimization,
     Handle<Object> object,
     Handle<JSObject> holder,
     Handle<Cell> cell,
     Handle<JSFunction> function,
     Handle<String> name) {
 
   Counters* counters = isolate()->counters();
 
@@ skipping 585 matching lines @@
   // -----------------------------------
   TailCallBuiltin(masm, Builtins::kKeyedLoadIC_Miss);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS