Mercurial > hg > truffle
view src/os_cpu/linux_x86/vm/bytes_linux_x86.inline.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 | d1605aabd0a1 |
children | c18cbe5936b8 |
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/* * Copyright 1999-2008 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. * */ #include <byteswap.h> // Efficient swapping of data bytes from Java byte // ordering to native byte ordering and vice versa. inline u2 Bytes::swap_u2(u2 x) { #ifdef AMD64 return bswap_16(x); #else u2 ret; __asm__ __volatile__ ( "movw %0, %%ax;" "xchg %%al, %%ah;" "movw %%ax, %0" :"=r" (ret) // output : register 0 => ret :"0" (x) // input : x => register 0 :"ax", "0" // clobbered registers ); return ret; #endif // AMD64 } inline u4 Bytes::swap_u4(u4 x) { #ifdef AMD64 return bswap_32(x); #else u4 ret; __asm__ __volatile__ ( "bswap %0" :"=r" (ret) // output : register 0 => ret :"0" (x) // input : x => register 0 :"0" // clobbered register ); return ret; #endif // AMD64 } #ifdef AMD64 inline u8 Bytes::swap_u8(u8 x) { #ifdef SPARC_WORKS // workaround for SunStudio12 CR6615391 __asm__ __volatile__ ( "bswapq %0" :"=r" (x) // output : register 0 => x :"0" (x) // input : x => register 0 :"0" // clobbered register ); return x; #else return bswap_64(x); #endif } #else // Helper function for swap_u8 inline u8 Bytes::swap_u8_base(u4 x, u4 y) { return (((u8)swap_u4(x))<<32) | swap_u4(y); } inline u8 Bytes::swap_u8(u8 x) { return swap_u8_base(*(u4*)&x, *(((u4*)&x)+1)); } #endif // !AMD64