1 /*
   2  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2014, Red Hat Inc. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
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  24  */
  25 
  26 #ifndef CPU_AARCH64_VM_BYTES_AARCH64_HPP
  27 #define CPU_AARCH64_VM_BYTES_AARCH64_HPP
  28 
  29 #include "memory/allocation.hpp"
  30 
  31 class Bytes: AllStatic {
  32  public:
  33   // Returns true if the byte ordering used by Java is different from the native byte ordering
  34   // of the underlying machine. For example, this is true for Intel x86, but false for Solaris
  35   // on Sparc.
  36   static inline bool is_Java_byte_ordering_different(){ return true; }
  37 
  38 
  39   // Efficient reading and writing of unaligned unsigned data in platform-specific byte ordering
  40   // (no special code is needed since x86 CPUs can access unaligned data)
  41   static inline u2   get_native_u2(address p)         { return *(u2*)p; }
  42   static inline u4   get_native_u4(address p)         { return *(u4*)p; }
  43   static inline u8   get_native_u8(address p)         { return *(u8*)p; }
  44 
  45   static inline void put_native_u2(address p, u2 x)   { *(u2*)p = x; }
  46   static inline void put_native_u4(address p, u4 x)   { *(u4*)p = x; }
  47   static inline void put_native_u8(address p, u8 x)   { *(u8*)p = x; }
  48 
  49 
  50   // Efficient reading and writing of unaligned unsigned data in Java
  51   // byte ordering (i.e. big-endian ordering). Byte-order reversal is
  52   // needed since x86 CPUs use little-endian format.
  53   static inline u2   get_Java_u2(address p)           { return swap_u2(get_native_u2(p)); }
  54   static inline u4   get_Java_u4(address p)           { return swap_u4(get_native_u4(p)); }
  55   static inline u8   get_Java_u8(address p)           { return swap_u8(get_native_u8(p)); }
  56 
  57   static inline void put_Java_u2(address p, u2 x)     { put_native_u2(p, swap_u2(x)); }
  58   static inline void put_Java_u4(address p, u4 x)     { put_native_u4(p, swap_u4(x)); }
  59   static inline void put_Java_u8(address p, u8 x)     { put_native_u8(p, swap_u8(x)); }
  60 
  61 
  62   // Efficient swapping of byte ordering
  63   static inline u2   swap_u2(u2 x);                   // compiler-dependent implementation
  64   static inline u4   swap_u4(u4 x);                   // compiler-dependent implementation
  65   static inline u8   swap_u8(u8 x);
  66 };
  67 
  68 
  69 // The following header contains the implementations of swap_u2, swap_u4, and swap_u8[_base]
  70 
  71 #ifdef TARGET_OS_ARCH_linux_aarch64
  72 # include "bytes_linux_aarch64.inline.hpp"
  73 #endif
  74 
  75 #endif // CPU_AARCH64_VM_BYTES_AARCH64_HPP