MIPS: Fix for bug 245480. Calling new Array(a) with a single argument could result in creating a ho…

src/mips/lithium-codegen-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 3886 matching lines @@
   __ li(a0, Operand(instr->arity()));
   __ li(a2, Operand(instr->hydrogen()->property_cell()));
   ElementsKind kind = instr->hydrogen()->elements_kind();
   bool disable_allocation_sites =
       (AllocationSiteInfo::GetMode(kind) == TRACK_ALLOCATION_SITE);
 
   if (instr->arity() == 0) {
     ArrayNoArgumentConstructorStub stub(kind, disable_allocation_sites);
     CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
   } else if (instr->arity() == 1) {
+    Label done;
+    if (IsFastPackedElementsKind(kind)) {
+      Label packed_case;
+      // We might need a change here,
+      // look at the first argument.
+      __ lw(t1, MemOperand(sp, 0));
+      __ Branch(&packed_case, eq, t1, Operand(zero_reg));
+
+      ElementsKind holey_kind = GetHoleyElementsKind(kind);
+      ArraySingleArgumentConstructorStub stub(holey_kind,
+                                              disable_allocation_sites);
+      CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
+      __ jmp(&done);
+      __ bind(&packed_case);
+    }
+
     ArraySingleArgumentConstructorStub stub(kind, disable_allocation_sites);
     CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
+    __ bind(&done);
   } else {
     ArrayNArgumentsConstructorStub stub(kind, disable_allocation_sites);
     CallCode(stub.GetCode(isolate()), RelocInfo::CONSTRUCT_CALL, instr);
   }
 }
 
 
 void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
   CallRuntime(instr->function(), instr->arity(), instr);
 }
@@ skipping 1747 matching lines @@
   __ Subu(scratch, result, scratch);
   __ lw(result, FieldMemOperand(scratch,
                                 FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal