src/hotspot/share/runtime/arguments.cpp

*** 1916,11 ***
      jio_fprintf(defaultStream::error_stream(),
                  "LockingMode == 0 (LM_MONITOR) is not fully implemented on this architecture");
      return false;
    }
  #endif
! #if (defined(X86) || defined(PPC64)) && !defined(ZERO)
    if (LockingMode == LM_MONITOR && UseRTMForStackLocks) {
      jio_fprintf(defaultStream::error_stream(),
                  "LockingMode == 0 (LM_MONITOR) and -XX:+UseRTMForStackLocks are mutually exclusive");
  
      return false;
--- 1916,11 ---
      jio_fprintf(defaultStream::error_stream(),
                  "LockingMode == 0 (LM_MONITOR) is not fully implemented on this architecture");
      return false;
    }
  #endif
! #if defined(X86) && !defined(ZERO)
    if (LockingMode == LM_MONITOR && UseRTMForStackLocks) {
      jio_fprintf(defaultStream::error_stream(),
                  "LockingMode == 0 (LM_MONITOR) and -XX:+UseRTMForStackLocks are mutually exclusive");
  
      return false;

*** 3083,10 ***
--- 3083,32 ---
  
  #ifndef CAN_SHOW_REGISTERS_ON_ASSERT
    UNSUPPORTED_OPTION(ShowRegistersOnAssert);
  #endif // CAN_SHOW_REGISTERS_ON_ASSERT
  
+ #ifdef _LP64
+   if (UseCompactObjectHeaders && UseZGC && !ZGenerational) {
+     if (FLAG_IS_CMDLINE(UseCompactObjectHeaders)) {
+       warning("Single-generational ZGC does not work with compact object headers, disabling UseCompactObjectHeaders");
+     }
+     FLAG_SET_DEFAULT(UseCompactObjectHeaders, false);
+   }
+   if (UseCompactObjectHeaders && FLAG_IS_CMDLINE(UseCompressedClassPointers) && !UseCompressedClassPointers) {
+     warning("Compact object headers require compressed class pointers. Disabling compact object headers.");
+     FLAG_SET_DEFAULT(UseCompactObjectHeaders, false);
+   }
+   if (UseCompactObjectHeaders && LockingMode == LM_LEGACY) {
+     FLAG_SET_DEFAULT(LockingMode, LM_LIGHTWEIGHT);
+   }
+   if (UseCompactObjectHeaders && !UseAltGCForwarding) {
+     FLAG_SET_DEFAULT(UseAltGCForwarding, true);
+   }
+   if (UseCompactObjectHeaders && !UseCompressedClassPointers) {
+     FLAG_SET_DEFAULT(UseCompressedClassPointers, true);
+   }
+ #endif
+ 
    return JNI_OK;
  }
  
  // Helper class for controlling the lifetime of JavaVMInitArgs
  // objects.  The contents of the JavaVMInitArgs are guaranteed to be