src/cpu/x86/vm/vm_version_x86.cpp

rev 3419 : 7023898: Intrinsify AtomicLongFieldUpdater.getAndIncrement()
Summary: use shorter instruction sequences for atomic add and atomic exchange when possible.
Reviewed-by:

*** 361,370 ****
--- 361,375 ----
        _logical_processors_per_package = logical_processor_count();
      }
    }
  
    _supports_cx8 = supports_cmpxchg8();
+   // xchg and xadd instructions
+   _supports_atomic_getset4 = true;
+   _supports_atomic_getadd4 = true;
+   LP64_ONLY(_supports_atomic_getset8 = true);
+   LP64_ONLY(_supports_atomic_getadd8 = true);
  
  #ifdef _LP64
    // OS should support SSE for x64 and hardware should support at least SSE2.
    if (!VM_Version::supports_sse2()) {
      vm_exit_during_initialization("Unknown x64 processor: SSE2 not supported");