src/cpu/x86/vm/x86_32.ad

*** 3369,3379 ****
  
        if (EmitSync & 8192) { 
           masm.movptr(Address(boxReg, 0), 3) ;            // results in ST-before-CAS penalty
           masm.get_thread (scrReg) ; 
           masm.movptr(boxReg, tmpReg);                    // consider: LEA box, [tmp-2] 
!          masm.movptr(tmpReg, 0);                         // consider: xor vs mov
           if (os::is_MP()) { masm.lock(); } 
           masm.cmpxchgptr(scrReg, Address(boxReg, ObjectMonitor::owner_offset_in_bytes()-2)) ; 
        } else 
        if ((EmitSync & 128) == 0) {                      // avoid ST-before-CAS
           masm.movptr(scrReg, boxReg) ; 
--- 3369,3379 ----
  
        if (EmitSync & 8192) { 
           masm.movptr(Address(boxReg, 0), 3) ;            // results in ST-before-CAS penalty
           masm.get_thread (scrReg) ; 
           masm.movptr(boxReg, tmpReg);                    // consider: LEA box, [tmp-2] 
!          masm.movptr(tmpReg, NULL_WORD);                 // consider: xor vs mov
           if (os::is_MP()) { masm.lock(); } 
           masm.cmpxchgptr(scrReg, Address(boxReg, ObjectMonitor::owner_offset_in_bytes()-2)) ; 
        } else 
        if ((EmitSync & 128) == 0) {                      // avoid ST-before-CAS
           masm.movptr(scrReg, boxReg) ; 
*** 3385,3395 ****
              masm.prefetchw(Address(rax, ObjectMonitor::owner_offset_in_bytes()-2));
           }
  
           if ((EmitSync & 64) == 0) {
             // Optimistic form: consider XORL tmpReg,tmpReg
!            masm.movptr(tmpReg, 0 ) ; 
           } else { 
             // Can suffer RTS->RTO upgrades on shared or cold $ lines
             // Test-And-CAS instead of CAS
             masm.movptr(tmpReg, Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2)) ;   // rax, = m->_owner
             masm.testptr(tmpReg, tmpReg) ;                   // Locked ? 
--- 3385,3395 ----
              masm.prefetchw(Address(rax, ObjectMonitor::owner_offset_in_bytes()-2));
           }
  
           if ((EmitSync & 64) == 0) {
             // Optimistic form: consider XORL tmpReg,tmpReg
!            masm.movptr(tmpReg, NULL_WORD) ; 
           } else { 
             // Can suffer RTS->RTO upgrades on shared or cold $ lines
             // Test-And-CAS instead of CAS
             masm.movptr(tmpReg, Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2)) ;   // rax, = m->_owner
             masm.testptr(tmpReg, tmpReg) ;                   // Locked ? 
*** 3585,3604 ****
           masm.xorptr(boxReg, Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2)) ;  
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::recursions_offset_in_bytes()-2)) ;
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::EntryList_offset_in_bytes()-2)) ; 
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::cxq_offset_in_bytes()-2)) ; 
           masm.jccb  (Assembler::notZero, DONE_LABEL) ; 
!          masm.movptr(Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2), 0) ; 
           masm.jmpb  (DONE_LABEL) ; 
        } else { 
           masm.xorptr(boxReg, Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2)) ;  
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::recursions_offset_in_bytes()-2)) ;
           masm.jccb  (Assembler::notZero, DONE_LABEL) ; 
           masm.movptr(boxReg, Address (tmpReg, ObjectMonitor::EntryList_offset_in_bytes()-2)) ; 
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::cxq_offset_in_bytes()-2)) ; 
           masm.jccb  (Assembler::notZero, CheckSucc) ; 
!          masm.movptr(Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2), 0) ; 
           masm.jmpb  (DONE_LABEL) ; 
        }
  
        // The Following code fragment (EmitSync & 65536) improves the performance of
        // contended applications and contended synchronization microbenchmarks.
--- 3585,3604 ----
           masm.xorptr(boxReg, Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2)) ;  
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::recursions_offset_in_bytes()-2)) ;
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::EntryList_offset_in_bytes()-2)) ; 
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::cxq_offset_in_bytes()-2)) ; 
           masm.jccb  (Assembler::notZero, DONE_LABEL) ; 
!          masm.movptr(Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2), NULL_WORD) ; 
           masm.jmpb  (DONE_LABEL) ; 
        } else { 
           masm.xorptr(boxReg, Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2)) ;  
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::recursions_offset_in_bytes()-2)) ;
           masm.jccb  (Assembler::notZero, DONE_LABEL) ; 
           masm.movptr(boxReg, Address (tmpReg, ObjectMonitor::EntryList_offset_in_bytes()-2)) ; 
           masm.orptr(boxReg, Address (tmpReg, ObjectMonitor::cxq_offset_in_bytes()-2)) ; 
           masm.jccb  (Assembler::notZero, CheckSucc) ; 
!          masm.movptr(Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2), NULL_WORD) ; 
           masm.jmpb  (DONE_LABEL) ; 
        }
  
        // The Following code fragment (EmitSync & 65536) improves the performance of
        // contended applications and contended synchronization microbenchmarks.
*** 3642,3652 ****
           //     remains in M-state for the lock:orl.
           //
           // We currently use (3), although it's likely that switching to (2)
           // is correct for the future.
              
!          masm.movptr(Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2), 0) ; 
           if (os::is_MP()) { 
              if (VM_Version::supports_sse2() && 1 == FenceInstruction) { 
                masm.mfence();
              } else { 
                masm.lock () ; masm.addptr(Address(rsp, 0), 0) ; 
--- 3642,3652 ----
           //     remains in M-state for the lock:orl.
           //
           // We currently use (3), although it's likely that switching to (2)
           // is correct for the future.
              
!          masm.movptr(Address (tmpReg, ObjectMonitor::owner_offset_in_bytes()-2), NULL_WORD) ; 
           if (os::is_MP()) { 
              if (VM_Version::supports_sse2() && 1 == FenceInstruction) { 
                masm.mfence();
              } else { 
                masm.lock () ; masm.addptr(Address(rsp, 0), 0) ;