--- a/src/hotspot/share/compiler/compilerDefinitions.cpp	Thu Oct 31 07:53:16 2019 +0100
+++ b/src/hotspot/share/compiler/compilerDefinitions.cpp	Tue Nov 05 09:37:20 2019 +0800
@@ -211,7 +211,6 @@
   }
 }
 
-#endif // TIERED
 
 void CompilerConfig::set_tiered_flags() {
   // Increase the code cache size - tiered compiles a lot more.
@@ -292,6 +291,8 @@
   }
 }
 
+#endif // TIERED
+
 #if INCLUDE_JVMCI
 void set_jvmci_specific_flags() {
   if (UseJVMCICompiler) {
@@ -474,9 +475,12 @@
   set_jvmci_specific_flags();
 #endif
 
+#ifdef TIERED
   if (TieredCompilation) {
     set_tiered_flags();
-  } else {
+  } else
+#endif
+  {
     // Scale CompileThreshold
     // CompileThresholdScaling == 0.0 is equivalent to -Xint and leaves CompileThreshold unchanged.
     if (!FLAG_IS_DEFAULT(CompileThresholdScaling) && CompileThresholdScaling > 0.0) {

--- a/src/hotspot/share/compiler/compilerDefinitions.hpp	Thu Oct 31 07:53:16 2019 +0100
+++ b/src/hotspot/share/compiler/compilerDefinitions.hpp	Tue Nov 05 09:37:20 2019 +0800
@@ -62,6 +62,7 @@
   CompLevel_full_optimization = 4          // C2 or JVMCI
 };
 
+#ifdef TIERED
 class CompilationModeFlag : AllStatic {
   static bool _quick_only;
   static bool _high_only;
@@ -79,6 +80,7 @@
 
   static void set_high_only_quick_internal(bool x) { _high_only_quick_internal = x; }
 };
+#endif
 
 extern CompLevel CompLevel_highest_tier;
 extern CompLevel CompLevel_initial_compile;
@@ -147,7 +149,7 @@
   static void ergo_initialize();
 
 private:
-  static void set_tiered_flags();
+  TIERED_ONLY(static void set_tiered_flags();)
 };
 
 #endif // SHARE_COMPILER_COMPILERDEFINITIONS_HPP

--- a/src/hotspot/share/runtime/arguments.cpp	Thu Oct 31 07:53:16 2019 +0100
+++ b/src/hotspot/share/runtime/arguments.cpp	Tue Nov 05 09:37:20 2019 +0800
@@ -4029,6 +4029,12 @@
   no_shared_spaces("CDS Disabled");
 #endif // INCLUDE_CDS
 
+#ifndef TIERED
+  if (FLAG_IS_CMDLINE(CompilationMode)) {
+    warning("CompilationMode has no effect in non-tiered VMs");
+  }
+#endif
+
   return JNI_OK;
 }
 

--- a/src/hotspot/share/runtime/flags/jvmFlagConstraintsCompiler.cpp	Thu Oct 31 07:53:16 2019 +0100
+++ b/src/hotspot/share/runtime/flags/jvmFlagConstraintsCompiler.cpp	Tue Nov 05 09:37:20 2019 +0800
@@ -67,7 +67,7 @@
   int min_number_of_compiler_threads = 0;
 #if !defined(COMPILER1) && !defined(COMPILER2) && !INCLUDE_JVMCI
   // case 1
-#else
+#elif defined(TIERED)
   if (TieredCompilation) {
     if (TieredStopAtLevel < CompLevel_full_optimization || CompilationModeFlag::quick_only()) {
       min_number_of_compiler_threads = 1; // case 3
@@ -81,7 +81,9 @@
     } else {
       min_number_of_compiler_threads = 2;   // case 4 (tiered)
     }
-  } else {
+  } else
+#else
+  {
     min_number_of_compiler_threads = 1; // case 2
   }
 #endif