Mercurial > hg > truffle
view src/cpu/x86/vm/bytes_x86.hpp @ 453:c96030fff130
6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa
| author | ysr |
|---|---|
| date | Thu, 20 Nov 2008 16:56:09 -0800 |
| parents | a61af66fc99e |
| children | c18cbe5936b8 |
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/* * Copyright 1997-2001 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ class Bytes: AllStatic { private: #ifndef AMD64 // Helper function for swap_u8 static inline u8 swap_u8_base(u4 x, u4 y); // compiler-dependent implementation #endif // AMD64 public: // Returns true if the byte ordering used by Java is different from the native byte ordering // of the underlying machine. For example, this is true for Intel x86, but false for Solaris // on Sparc. static inline bool is_Java_byte_ordering_different(){ return true; } // Efficient reading and writing of unaligned unsigned data in platform-specific byte ordering // (no special code is needed since x86 CPUs can access 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; } // Efficient reading and writing of unaligned unsigned data in Java // byte ordering (i.e. big-endian ordering). Byte-order reversal is // needed since x86 CPUs use little-endian format. static inline u2 get_Java_u2(address p) { return swap_u2(get_native_u2(p)); } static inline u4 get_Java_u4(address p) { return swap_u4(get_native_u4(p)); } static inline u8 get_Java_u8(address p) { return swap_u8(get_native_u8(p)); } static inline void put_Java_u2(address p, u2 x) { put_native_u2(p, swap_u2(x)); } static inline void put_Java_u4(address p, u4 x) { put_native_u4(p, swap_u4(x)); } static inline void put_Java_u8(address p, u8 x) { put_native_u8(p, swap_u8(x)); } // Efficient swapping of byte ordering static inline u2 swap_u2(u2 x); // compiler-dependent implementation static inline u4 swap_u4(u4 x); // compiler-dependent implementation static inline u8 swap_u8(u8 x); }; // The following header contains the implementations of swap_u2, swap_u4, and swap_u8[_base] #include "incls/_bytes_pd.inline.hpp.incl"