src/hotspot/share/oops/accessDecorators.hpp

rev 51202 : 8205523: Explicit barriers for interpreter

*** 210,221 ****
  const DecoratorSet ARRAYCOPY_ALIGNED              = UCONST64(1) << 28;
  const DecoratorSet ARRAYCOPY_DECORATOR_MASK       = ARRAYCOPY_CHECKCAST | ARRAYCOPY_DISJOINT |
                                                      ARRAYCOPY_DISJOINT | ARRAYCOPY_ARRAYOF |
                                                      ARRAYCOPY_ATOMIC | ARRAYCOPY_ALIGNED;
  
  // Keep track of the last decorator.
! const DecoratorSet DECORATOR_LAST = UCONST64(1) << 28;
  
  namespace AccessInternal {
    // This class adds implied decorators that follow according to decorator rules.
    // For example adding default reference strength and default memory ordering
    // semantics.
--- 210,228 ----
  const DecoratorSet ARRAYCOPY_ALIGNED              = UCONST64(1) << 28;
  const DecoratorSet ARRAYCOPY_DECORATOR_MASK       = ARRAYCOPY_CHECKCAST | ARRAYCOPY_DISJOINT |
                                                      ARRAYCOPY_DISJOINT | ARRAYCOPY_ARRAYOF |
                                                      ARRAYCOPY_ATOMIC | ARRAYCOPY_ALIGNED;
  
+ // == Resolve barrier decorators ==
+ // * ACCESS_READ: Indicate that the resolved object is accessed read-only. This allows the GC
+ //   backend to use weaker and more efficient barriers.
+ // * ACCESS_WRITE: Indicate that the resolved object is used for write access.
+ const DecoratorSet ACCESS_READ                    = UCONST64(1) << 29;
+ const DecoratorSet ACCESS_WRITE                   = UCONST64(1) << 30;
+ 
  // Keep track of the last decorator.
! const DecoratorSet DECORATOR_LAST = UCONST64(1) << 30;
  
  namespace AccessInternal {
    // This class adds implied decorators that follow according to decorator rules.
    // For example adding default reference strength and default memory ordering
    // semantics.