diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 1142631..dc10830 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -456,7 +456,7 @@
   locations->AddTemp(X86CpuLocation(EAX));
 
   InvokeDexCallingConventionVisitor calling_convention_visitor;
-  for (int i = 0; i < invoke->InputCount(); i++) {
+  for (size_t i = 0; i < invoke->InputCount(); i++) {
     HInstruction* input = invoke->InputAt(i);
     locations->SetInAt(i, calling_convention_visitor.GetNextLocation(input->GetType()));
   }
@@ -687,5 +687,13 @@
   __ xorl(locations->Out().AsX86().AsCpuRegister(), Immediate(1));
 }
 
+void LocationsBuilderX86::VisitPhi(HPhi* instruction) {
+  LOG(FATAL) << "Unimplemented";
+}
+
+void InstructionCodeGeneratorX86::VisitPhi(HPhi* instruction) {
+  LOG(FATAL) << "Unimplemented";
+}
+
 }  // namespace x86
 }  // namespace art