MIPS: Implement code stub for object literal creation.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index e790798f77e18c6a579b4833c7e6d30c4659787e..eb1b17b6d26b1685b245f02c9f850f353225d0d7 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -4241,18 +4241,30 @@ void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
 
 void LCodeGen::DoObjectLiteral(LObjectLiteral* instr) {
   ASSERT(ToRegister(instr->result()).is(v0));
+
+  Handle<FixedArray> constant_properties =
+      instr->hydrogen()->constant_properties();
+
   __ lw(t0, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
   __ lw(t0, FieldMemOperand(t0, JSFunction::kLiteralsOffset));
   __ li(a3, Operand(Smi::FromInt(instr->hydrogen()->literal_index())));
-  __ li(a2, Operand(instr->hydrogen()->constant_properties()));
-  __ li(a1, Operand(Smi::FromInt(instr->hydrogen()->fast_elements() ? 1 : 0)));
+  __ li(a2, Operand(constant_properties));
+  int flags = instr->hydrogen()->fast_elements()
+      ? ObjectLiteral::kFastElements
+      : ObjectLiteral::kNoFlags;
+  __ li(a1, Operand(Smi::FromInt(flags)));
   __ Push(t0, a3, a2, a1);
 
   // Pick the right runtime function to call.
+  int properties_count = constant_properties->length() / 2;
   if (instr->hydrogen()->depth() > 1) {
     CallRuntime(Runtime::kCreateObjectLiteral, 4, instr);
-  } else {
+  } else if (flags != ObjectLiteral::kFastElements ||
+      properties_count > FastCloneShallowObjectStub::kMaximumClonedProperties) {
     CallRuntime(Runtime::kCreateObjectLiteralShallow, 4, instr);
+  } else {
+    FastCloneShallowObjectStub stub(properties_count);
+    CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
   }
 }