src/hotspot/cpu/ppc/vm_version_ppc.hpp

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#ifndef CPU_PPC_VM_VERSION_PPC_HPP
#define CPU_PPC_VM_VERSION_PPC_HPP

#include "runtime/abstract_vm_version.hpp"
#include "runtime/globals_extension.hpp"

class VM_Version: public Abstract_VM_Version {
protected:
  enum Feature_Flag {
    mfdscr,
    darn,
    brw,
    num_features // last entry to count features
  };
  enum Feature_Flag_Set {
    unknown_m             = 0,
    mfdscr_m              = (1 << mfdscr ),
    darn_m                = (1 << darn   ),
    brw_m                 = (1 << brw    ),
    all_features_m        = (unsigned long)-1
  };

  static bool _is_determine_features_test_running;

  static void print_features();
  static void determine_features(); // also measures cache line size
  static void config_dscr(); // Power 8: Configure Data Stream Control Register.

public:
  // Initialization
  static void initialize();
  static void check_virtualizations();

  // Override Abstract_VM_Version implementation
  static void print_platform_virtualization_info(outputStream*);

  // PPC64 supports fast class initialization checks
  static bool supports_fast_class_init_checks() { return true; }
  constexpr static bool supports_stack_watermark_barrier() { return true; }
  constexpr static bool supports_recursive_lightweight_locking() { return true; }
  constexpr static bool supports_secondary_supers_table() { return true; }

  static bool supports_float16() { return PowerArchitecturePPC64 >= 9; }

  static bool is_determine_features_test_running() { return _is_determine_features_test_running; }
  // CPU instruction support
  static bool has_mfdscr() { return (_features & mfdscr_m) != 0; } // Power8, but may be unavailable (QEMU)
  static bool has_darn()   { return (_features & darn_m) != 0; }
  static bool has_brw()    { return (_features & brw_m) != 0; }

  // Assembler testing
  static void allow_all();
  static void revert();

  // POWER 8: DSCR current value.
  static uint64_t _dscr_val;

  static void initialize_cpu_information(void);
};

#endif // CPU_PPC_VM_VERSION_PPC_HPP