1 /* 2 * Copyright (c) 1997, 2001, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 class Bytes: AllStatic { 26 private: 27 #ifndef AMD64 28 // Helper function for swap_u8 29 static inline u8 swap_u8_base(u4 x, u4 y); // compiler-dependent implementation 30 #endif // AMD64 31 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 #include "incls/_bytes_pd.inline.hpp.incl"