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  25 
  26 #ifndef CPU_AARCH64_VM_GLOBALDEFINITIONS_AARCH64_HPP
  27 #define CPU_AARCH64_VM_GLOBALDEFINITIONS_AARCH64_HPP
  28 
  29 const int StackAlignmentInBytes  = 16;
  30 
  31 #define SUPPORTS_NATIVE_CX8
  32 
  33 // The maximum B/BL offset range on AArch64 is 128MB.
  34 #undef CODE_CACHE_DEFAULT_LIMIT
  35 #define CODE_CACHE_DEFAULT_LIMIT (128*M)
  36 
  37 // According to the ARMv8 ARM, "Concurrent modification and execution
  38 // of instructions can lead to the resulting instruction performing
  39 // any behavior that can be achieved by executing any sequence of
  40 // instructions that can be executed from the same Exception level,
  41 // except where the instruction before modification and the
  42 // instruction after modification is a B, BL, NOP, BKPT, SVC, HVC, or
  43 // SMC instruction."
  44 //
  45 // This makes the games we play when patching difficult, so when we
  46 // come across an access that needs patching we deoptimize.  There are
  47 // ways we can avoid this, but these would slow down C1-compiled code
  48 // in the defauilt case.  We could revisit this decision if we get any
  49 // evidence that it's worth doing.
  50 #define DEOPTIMIZE_WHEN_PATCHING
  51 
  52 #endif // CPU_AARCH64_VM_GLOBALDEFINITIONS_AARCH64_HPP