[~roland] noticed that the MemBarCPUOrder is not correctly inserted into the graph when InsertMemBarAfterArraycopy is disabled. Control is updated but never used:

    if (!InsertMemBarAfterArraycopy) {
      // (If InsertMemBarAfterArraycopy, there is already one in place.)
      insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder);
    }

Also, running with -XX:-InsertMemBarAfterArraycopy hits several asserts:

#  Internal Error (t:\workspace\open\src\hotspot\share\opto/node.hpp:864), pid=24008, tid=30468
#  assert(is_MemBar()) failed: invalid node class

Current CompileTask:
C2:   1434  556       4       sun.jvm.hotspot.utilities.CStringUtilities::getString (124 bytes)

Stack: [0x000000f23ce00000,0x000000f23cf00000]
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [jvm.dll+0xa60c31]  os::platform_print_native_stack+0xf1  (os_windows_x86.cpp:236)
V  [jvm.dll+0xc7f4e7]  VMError::report+0xf97  (vmError.cpp:732)
V  [jvm.dll+0xc80d9e]  VMError::report_and_die+0x7de  (vmError.cpp:1548)
V  [jvm.dll+0xc81454]  VMError::report_and_die+0x64  (vmError.cpp:1341)
V  [jvm.dll+0x441377]  report_vm_error+0x117  (debug.cpp:264)
V  [jvm.dll+0x925933]  PhaseMacroExpand::generate_arraycopy+0x2443  (macroArrayCopy.cpp:726)
V  [jvm.dll+0x92324a]  PhaseMacroExpand::expand_arraycopy_node+0xbca  (macroArrayCopy.cpp:1117)
V  [jvm.dll+0x918447]  PhaseMacroExpand::expand_macro_nodes+0xa97  (macro.cpp:2765)
V  [jvm.dll+0x3fc7ef]  Compile::Optimize+0x125f  (compile.cpp:2216)
V  [jvm.dll+0x3f90f9]  Compile::Compile+0x1129  (compile.cpp:732)
V  [jvm.dll+0x3335fc]  C2Compiler::compile_method+0x12c  (c2compiler.cpp:105)
V  [jvm.dll+0x41113e]  CompileBroker::invoke_compiler_on_method+0x8be  (compileBroker.cpp:2229)
V  [jvm.dll+0x40ef75]  CompileBroker::compiler_thread_loop+0x315  (compileBroker.cpp:1903)
V  [jvm.dll+0xc1a579]  JavaThread::run+0x2f9  (thread.cpp:1993)
V  [jvm.dll+0xc10894]  Thread::call_run+0x1b4  (thread.cpp:400)
V  [jvm.dll+0xa5f62e]  thread_native_entry+0x10e  (os_windows.cpp:463)
C  [ucrtbase.dll+0x1fb80]  _o__realloc_base+0x60
C  [KERNEL32.DLL+0x84d4]  BaseThreadInitThunk+0x14
C  [ntdll.dll+0x6e871]  RtlUserThreadStart+0x21


#  Internal Error (.../workspace/open/src/hotspot/share/opto/loopnode.cpp:1129), pid=19677, tid=19707
#  assert(outer->outcnt() >= phis + 2 && outer->outcnt() <= phis + 2 + stores + 1) failed: only phis

Current CompileTask:
C2:  32871 3694    b        javax.management.ObjectName::setCanonicalName (251 bytes)

Stack: [0x00007f3210aed000,0x00007f3210bee000],  sp=0x00007f3210be9120,  free space=1008k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x12277de]  LoopNode::verify_strip_mined(int) const+0xbde
V  [libjvm.so+0x919e79]  Compile::final_graph_reshaping_main_switch(Node*, Final_Reshape_Counts&, unsigned int)+0x3c9
V  [libjvm.so+0x91bd05]  Compile::final_graph_reshaping_impl(Node*, Final_Reshape_Counts&) [clone .part.0]+0x85
V  [libjvm.so+0x91c528]  Compile::final_graph_reshaping_walk(Node_Stack&, Node*, Final_Reshape_Counts&)+0x1c8
V  [libjvm.so+0x922d8c]  Compile::final_graph_reshaping()+0x41c
V  [libjvm.so+0x927d2b]  Compile::Optimize()+0x10db
V  [libjvm.so+0x9292f9]  Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x1529
V  [libjvm.so+0x76dc34]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x184
V  [libjvm.so+0x938a48]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0xe98
V  [libjvm.so+0x939608]  CompileBroker::compiler_thread_loop()+0x5a8
V  [libjvm.so+0x17901f6]  JavaThread::thread_main_inner()+0x256
V  [libjvm.so+0x17965d0]  Thread::call_run()+0x100
V  [libjvm.so+0x148e9a6]  thread_native_entry(Thread*)+0x116