MIPS: Fix for bug 245480. Calling new Array(a) with a single argument could...

MIPS: Fix for bug 245480. Calling new Array(a) with a single argument could result in creating a holey array with a packed elements kind.

Port r15095 (4a97e1e4)

BUG=

Review URL: https://codereview.chromium.org/16861003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15104 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -3903,8 +3903,25 @@ void LCodeGen::DoCallNewArray(LCallNewArray* instr) {
     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);