--- a/hotspot/src/cpu/aarch64/vm/interp_masm_aarch64.cpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/aarch64/vm/interp_masm_aarch64.cpp	Thu Oct 13 11:27:20 2016 +0200
@@ -692,7 +692,7 @@
     }
 
     // Load (object->mark() | 1) into swap_reg
-    ldr(rscratch1, Address(obj_reg, 0));
+    ldr(rscratch1, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
     orr(swap_reg, rscratch1, 1);
 
     // Save (object->mark() | 1) into BasicLock's displaced header
@@ -704,14 +704,14 @@
     Label fail;
     if (PrintBiasedLockingStatistics) {
       Label fast;
-      cmpxchgptr(swap_reg, lock_reg, obj_reg, rscratch1, fast, &fail);
+      cmpxchg_obj_header(swap_reg, lock_reg, obj_reg, rscratch1, fast, &fail);
       bind(fast);
       atomic_incw(Address((address)BiasedLocking::fast_path_entry_count_addr()),
                   rscratch2, rscratch1, tmp);
       b(done);
       bind(fail);
     } else {
-      cmpxchgptr(swap_reg, lock_reg, obj_reg, rscratch1, done, /*fallthrough*/NULL);
+      cmpxchg_obj_header(swap_reg, lock_reg, obj_reg, rscratch1, done, /*fallthrough*/NULL);
     }
 
     // Test if the oopMark is an obvious stack pointer, i.e.,
@@ -801,7 +801,7 @@
     cbz(header_reg, done);
 
     // Atomic swap back the old header
-    cmpxchgptr(swap_reg, header_reg, obj_reg, rscratch1, done, /*fallthrough*/NULL);
+    cmpxchg_obj_header(swap_reg, header_reg, obj_reg, rscratch1, done, /*fallthrough*/NULL);
 
     // Call the runtime routine for slow case.
     str(obj_reg, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes())); // restore obj

--- a/hotspot/src/cpu/aarch64/vm/macroAssembler_aarch64.cpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/aarch64/vm/macroAssembler_aarch64.cpp	Thu Oct 13 11:27:20 2016 +0200
@@ -515,7 +515,7 @@
     mov(rscratch1, markOopDesc::biased_lock_mask_in_place | markOopDesc::age_mask_in_place | markOopDesc::epoch_mask_in_place);
     andr(swap_reg, swap_reg, rscratch1);
     orr(tmp_reg, swap_reg, rthread);
-    cmpxchgptr(swap_reg, tmp_reg, obj_reg, rscratch1, here, slow_case);
+    cmpxchg_obj_header(swap_reg, tmp_reg, obj_reg, rscratch1, here, slow_case);
     // If the biasing toward our thread failed, this means that
     // another thread succeeded in biasing it toward itself and we
     // need to revoke that bias. The revocation will occur in the
@@ -542,7 +542,7 @@
     Label here;
     load_prototype_header(tmp_reg, obj_reg);
     orr(tmp_reg, rthread, tmp_reg);
-    cmpxchgptr(swap_reg, tmp_reg, obj_reg, rscratch1, here, slow_case);
+    cmpxchg_obj_header(swap_reg, tmp_reg, obj_reg, rscratch1, here, slow_case);
     // If the biasing toward our thread failed, then another thread
     // succeeded in biasing it toward itself and we need to revoke that
     // bias. The revocation will occur in the runtime in the slow case.
@@ -569,7 +569,7 @@
   {
     Label here, nope;
     load_prototype_header(tmp_reg, obj_reg);
-    cmpxchgptr(swap_reg, tmp_reg, obj_reg, rscratch1, here, &nope);
+    cmpxchg_obj_header(swap_reg, tmp_reg, obj_reg, rscratch1, here, &nope);
     bind(here);
 
     // Fall through to the normal CAS-based lock, because no matter what
@@ -2140,6 +2140,12 @@
     b(*fail);
 }
 
+void MacroAssembler::cmpxchg_obj_header(Register oldv, Register newv, Register obj, Register tmp,
+                                        Label &succeed, Label *fail) {
+  assert(oopDesc::mark_offset_in_bytes() == 0, "assumption");
+  cmpxchgptr(oldv, newv, obj, tmp, succeed, fail);
+}
+
 void MacroAssembler::cmpxchgw(Register oldv, Register newv, Register addr, Register tmp,
                                 Label &succeed, Label *fail) {
   // oldv holds comparison value

--- a/hotspot/src/cpu/aarch64/vm/macroAssembler_aarch64.hpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/aarch64/vm/macroAssembler_aarch64.hpp	Thu Oct 13 11:27:20 2016 +0200
@@ -974,6 +974,8 @@
 
   // Various forms of CAS
 
+  void cmpxchg_obj_header(Register oldv, Register newv, Register obj, Register tmp,
+                          Label &suceed, Label *fail);
   void cmpxchgptr(Register oldv, Register newv, Register addr, Register tmp,
                   Label &suceed, Label *fail);
 

--- a/hotspot/src/cpu/aarch64/vm/sharedRuntime_aarch64.cpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/aarch64/vm/sharedRuntime_aarch64.cpp	Thu Oct 13 11:27:20 2016 +0200
@@ -1842,7 +1842,7 @@
     }
 
     // Load (object->mark() | 1) into swap_reg %r0
-    __ ldr(rscratch1, Address(obj_reg, 0));
+    __ ldr(rscratch1, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
     __ orr(swap_reg, rscratch1, 1);
 
     // Save (object->mark() | 1) into BasicLock's displaced header
@@ -1850,7 +1850,7 @@
 
     // src -> dest iff dest == r0 else r0 <- dest
     { Label here;
-      __ cmpxchgptr(r0, lock_reg, obj_reg, rscratch1, lock_done, /*fallthrough*/NULL);
+      __ cmpxchg_obj_header(r0, lock_reg, obj_reg, rscratch1, lock_done, /*fallthrough*/NULL);
     }
 
     // Hmm should this move to the slow path code area???
@@ -2029,7 +2029,7 @@
 
     // Atomic swap old header if oop still contains the stack lock
     Label succeed;
-    __ cmpxchgptr(r0, old_hdr, obj_reg, rscratch1, succeed, &slow_path_unlock);
+    __ cmpxchg_obj_header(r0, old_hdr, obj_reg, rscratch1, succeed, &slow_path_unlock);
     __ bind(succeed);
 
     // slow path re-enters here

--- a/hotspot/src/cpu/x86/vm/interp_masm_x86.cpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/x86/vm/interp_masm_x86.cpp	Thu Oct 13 11:27:20 2016 +0200
@@ -1157,7 +1157,7 @@
     movl(swap_reg, (int32_t)1);
 
     // Load (object->mark() | 1) into swap_reg %rax
-    orptr(swap_reg, Address(obj_reg, 0));
+    orptr(swap_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
 
     // Save (object->mark() | 1) into BasicLock's displaced header
     movptr(Address(lock_reg, mark_offset), swap_reg);
@@ -1166,7 +1166,7 @@
            "displaced header must be first word in BasicObjectLock");
 
     if (os::is_MP()) lock();
-    cmpxchgptr(lock_reg, Address(obj_reg, 0));
+    cmpxchgptr(lock_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
     if (PrintBiasedLockingStatistics) {
       cond_inc32(Assembler::zero,
                  ExternalAddress((address) BiasedLocking::fast_path_entry_count_addr()));
@@ -1263,7 +1263,7 @@
 
     // Atomic swap back the old header
     if (os::is_MP()) lock();
-    cmpxchgptr(header_reg, Address(obj_reg, 0));
+    cmpxchgptr(header_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
 
     // zero for simple unlock of a stack-lock case
     jcc(Assembler::zero, done);

--- a/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/x86/vm/macroAssembler_x86.cpp	Thu Oct 13 11:27:20 2016 +0200
@@ -1484,7 +1484,7 @@
     movl(retry_on_abort_count_Reg, RTMRetryCount); // Retry on abort
     bind(L_rtm_retry);
   }
-  movptr(tmpReg, Address(objReg, 0));
+  movptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes()));
   testptr(tmpReg, markOopDesc::monitor_value);  // inflated vs stack-locked|neutral|biased
   jcc(Assembler::notZero, IsInflated);
 
@@ -1499,7 +1499,7 @@
     bind(L_noincrement);
   }
   xbegin(L_on_abort);
-  movptr(tmpReg, Address(objReg, 0));       // fetch markword
+  movptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes()));       // fetch markword
   andptr(tmpReg, markOopDesc::biased_lock_mask_in_place); // look at 3 lock bits
   cmpptr(tmpReg, markOopDesc::unlocked_value);            // bits = 001 unlocked
   jcc(Assembler::equal, DONE_LABEL);        // all done if unlocked
@@ -1560,7 +1560,7 @@
     bind(L_noincrement);
   }
   xbegin(L_on_abort);
-  movptr(tmpReg, Address(objReg, 0));
+  movptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes()));
   movptr(tmpReg, Address(tmpReg, owner_offset));
   testptr(tmpReg, tmpReg);
   jcc(Assembler::zero, DONE_LABEL);
@@ -1753,7 +1753,7 @@
     }
 #endif // INCLUDE_RTM_OPT
 
-    movptr(tmpReg, Address(objReg, 0));          // [FETCH]
+    movptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes()));          // [FETCH]
     testptr(tmpReg, markOopDesc::monitor_value); // inflated vs stack-locked|neutral|biased
     jccb(Assembler::notZero, IsInflated);
 
@@ -1763,7 +1763,7 @@
     if (os::is_MP()) {
       lock();
     }
-    cmpxchgptr(boxReg, Address(objReg, 0));      // Updates tmpReg
+    cmpxchgptr(boxReg, Address(objReg, oopDesc::mark_offset_in_bytes()));      // Updates tmpReg
     if (counters != NULL) {
       cond_inc32(Assembler::equal,
                  ExternalAddress((address)counters->fast_path_entry_count_addr()));
@@ -1984,7 +1984,7 @@
     if (UseRTMForStackLocks && use_rtm) {
       assert(!UseBiasedLocking, "Biased locking is not supported with RTM locking");
       Label L_regular_unlock;
-      movptr(tmpReg, Address(objReg, 0));           // fetch markword
+      movptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes()));           // fetch markword
       andptr(tmpReg, markOopDesc::biased_lock_mask_in_place); // look at 3 lock bits
       cmpptr(tmpReg, markOopDesc::unlocked_value);            // bits = 001 unlocked
       jccb(Assembler::notEqual, L_regular_unlock);  // if !HLE RegularLock
@@ -1996,7 +1996,7 @@
 
     cmpptr(Address(boxReg, 0), (int32_t)NULL_WORD); // Examine the displaced header
     jcc   (Assembler::zero, DONE_LABEL);            // 0 indicates recursive stack-lock
-    movptr(tmpReg, Address(objReg, 0));             // Examine the object's markword
+    movptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes()));             // Examine the object's markword
     testptr(tmpReg, markOopDesc::monitor_value);    // Inflated?
     jccb  (Assembler::zero, Stacked);
 
@@ -2150,7 +2150,7 @@
     if (os::is_MP()) {
       lock();
     }
-    cmpxchgptr(tmpReg, Address(objReg, 0)); // Uses RAX which is box
+    cmpxchgptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes())); // Uses RAX which is box
     // Intention fall-thru into DONE_LABEL
 
     // DONE_LABEL is a hot target - we'd really like to place it at the
@@ -2247,7 +2247,7 @@
     bind  (Stacked);
     movptr(tmpReg, Address (boxReg, 0));      // re-fetch
     if (os::is_MP()) { lock(); }
-    cmpxchgptr(tmpReg, Address(objReg, 0)); // Uses RAX which is box
+    cmpxchgptr(tmpReg, Address(objReg, oopDesc::mark_offset_in_bytes())); // Uses RAX which is box
 
     if (EmitSync & 65536) {
        bind (CheckSucc);

--- a/hotspot/src/cpu/x86/vm/sharedRuntime_x86_32.cpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/x86/vm/sharedRuntime_x86_32.cpp	Thu Oct 13 11:27:20 2016 +0200
@@ -1998,7 +1998,7 @@
     __ movptr(swap_reg, 1);
 
     // Load (object->mark() | 1) into swap_reg %rax,
-    __ orptr(swap_reg, Address(obj_reg, 0));
+    __ orptr(swap_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
 
     // Save (object->mark() | 1) into BasicLock's displaced header
     __ movptr(Address(lock_reg, mark_word_offset), swap_reg);
@@ -2009,7 +2009,7 @@
 
     // src -> dest iff dest == rax, else rax, <- dest
     // *obj_reg = lock_reg iff *obj_reg == rax, else rax, = *(obj_reg)
-    __ cmpxchgptr(lock_reg, Address(obj_reg, 0));
+    __ cmpxchgptr(lock_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
     __ jcc(Assembler::equal, lock_done);
 
     // Test if the oopMark is an obvious stack pointer, i.e.,
@@ -2204,7 +2204,7 @@
 
     // src -> dest iff dest == rax, else rax, <- dest
     // *obj_reg = rbx, iff *obj_reg == rax, else rax, = *(obj_reg)
-    __ cmpxchgptr(rbx, Address(obj_reg, 0));
+    __ cmpxchgptr(rbx, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
     __ jcc(Assembler::notEqual, slow_path_unlock);
 
     // slow path re-enters here

--- a/hotspot/src/cpu/x86/vm/sharedRuntime_x86_64.cpp	Tue May 09 13:50:06 2017 -0400
+++ b/hotspot/src/cpu/x86/vm/sharedRuntime_x86_64.cpp	Thu Oct 13 11:27:20 2016 +0200
@@ -2372,7 +2372,7 @@
     __ movl(swap_reg, 1);
 
     // Load (object->mark() | 1) into swap_reg %rax
-    __ orptr(swap_reg, Address(obj_reg, 0));
+    __ orptr(swap_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
 
     // Save (object->mark() | 1) into BasicLock's displaced header
     __ movptr(Address(lock_reg, mark_word_offset), swap_reg);
@@ -2382,7 +2382,7 @@
     }
 
     // src -> dest iff dest == rax else rax <- dest
-    __ cmpxchgptr(lock_reg, Address(obj_reg, 0));
+    __ cmpxchgptr(lock_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
     __ jcc(Assembler::equal, lock_done);
 
     // Hmm should this move to the slow path code area???
@@ -2560,7 +2560,7 @@
     if (os::is_MP()) {
       __ lock();
     }
-    __ cmpxchgptr(old_hdr, Address(obj_reg, 0));
+    __ cmpxchgptr(old_hdr, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
     __ jcc(Assembler::notEqual, slow_path_unlock);
 
     // slow path re-enters here