src/cpu/x86/vm/stubGenerator_x86_64.cpp

rev 7007 : Summary: Patch from Erik ?sterlund

*** 592,601 ****
--- 592,627 ----
      __ ret(0);
  
      return start;
    }
  
+   // Support for jbyte atomic::atomic_cmpxchg(jbyte exchange_value, volatile jbyte* dest,
+   //                                          jbyte compare_value)
+   //
+   // Arguments :
+   //    c_rarg0: exchange_value
+   //    c_rarg1: dest
+   //    c_rarg2: compare_value
+   //
+   // Result:
+   //    if ( compare_value == *dest ) {
+   //       *dest = exchange_value
+   //       return compare_value;
+   //    else
+   //       return *dest;
+   address generate_atomic_cmpxchg_byte() {
+     StubCodeMark mark(this, "StubRoutines", "atomic_cmpxchg_byte");
+     address start = __ pc();
+ 
+     __ movsbq(rax, c_rarg2);
+    if ( os::is_MP() ) __ lock();
+     __ cmpxchgb(c_rarg0, Address(c_rarg1, 0));
+     __ ret(0);
+ 
+     return start;
+   }
+ 
    // Support for jint atomic::atomic_cmpxchg_long(jlong exchange_value,
    //                                             volatile jlong* dest,
    //                                             jlong compare_value)
    // Arguments :
    //    c_rarg0: exchange_value
*** 3892,3901 ****
--- 3918,3928 ----
  
      // atomic calls
      StubRoutines::_atomic_xchg_entry         = generate_atomic_xchg();
      StubRoutines::_atomic_xchg_ptr_entry     = generate_atomic_xchg_ptr();
      StubRoutines::_atomic_cmpxchg_entry      = generate_atomic_cmpxchg();
+     StubRoutines::_atomic_cmpxchg_byte_entry = generate_atomic_cmpxchg_byte();
      StubRoutines::_atomic_cmpxchg_long_entry = generate_atomic_cmpxchg_long();
      StubRoutines::_atomic_add_entry          = generate_atomic_add();
      StubRoutines::_atomic_add_ptr_entry      = generate_atomic_add_ptr();
      StubRoutines::_fence_entry               = generate_orderaccess_fence();