bytes_s390.hpp

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#ifndef CPU_S390_BYTES_S390_HPP
#define CPU_S390_BYTES_S390_HPP

#include "memory/allocation.hpp"

class Bytes: AllStatic {
 public:
  // Efficient reading and writing of unaligned unsigned data in
  // platform-specific byte ordering.

  // Use regular load and store for unaligned access.
  //
  // On z/Architecture, unaligned loads and stores are supported when using the
  // "traditional" load (LH, L/LY, LG) and store (STH, ST/STY, STG) instructions.
  // The penalty for unaligned access is just very few (two or three) ticks,
  // plus another few (two or three) ticks if the access crosses a cache line boundary.
  //
  // In short, it makes no sense on z/Architecture to piecemeal get or put unaligned data.

  static inline u2   get_native_u2(address p) { return *(u2*)p; }
  static inline u4   get_native_u4(address p) { return *(u4*)p; }
  static inline u8   get_native_u8(address p) { return *(u8*)p; }

  static inline void put_native_u2(address p, u2 x) { *(u2*)p = x; }
  static inline void put_native_u4(address p, u4 x) { *(u4*)p = x; }
  static inline void put_native_u8(address p, u8 x) { *(u8*)p = x; }

  // The following header contains the implementations of swap_u2, swap_u4, and swap_u8.
#include OS_CPU_HEADER(bytes)

  // Efficient reading and writing of unaligned unsigned data in Java byte ordering (i.e. big-endian ordering)
  static inline u2   get_Java_u2(address p) { return get_native_u2(p); }
  static inline u4   get_Java_u4(address p) { return get_native_u4(p); }
  static inline u8   get_Java_u8(address p) { return get_native_u8(p); }

  static inline void put_Java_u2(address p, u2 x) { put_native_u2(p, x); }
  static inline void put_Java_u4(address p, u4 x) { put_native_u4(p, x); }
  static inline void put_Java_u8(address p, u8 x) { put_native_u8(p, x); }
};

#endif // CPU_S390_BYTES_S390_HPP