Mercurial > hg > truffle
view src/share/vm/utilities/copy.cpp @ 4877:c03e06373b47
Merge
author | stefank |
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date | Sat, 28 Jan 2012 01:15:34 -0800 |
parents | f95d63e2154a |
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/* * Copyright (c) 2006, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "runtime/sharedRuntime.hpp" #include "utilities/copy.hpp" // Copy bytes; larger units are filled atomically if everything is aligned. void Copy::conjoint_memory_atomic(void* from, void* to, size_t size) { address src = (address) from; address dst = (address) to; uintptr_t bits = (uintptr_t) src | (uintptr_t) dst | (uintptr_t) size; // (Note: We could improve performance by ignoring the low bits of size, // and putting a short cleanup loop after each bulk copy loop. // There are plenty of other ways to make this faster also, // and it's a slippery slope. For now, let's keep this code simple // since the simplicity helps clarify the atomicity semantics of // this operation. There are also CPU-specific assembly versions // which may or may not want to include such optimizations.) if (bits % sizeof(jlong) == 0) { Copy::conjoint_jlongs_atomic((jlong*) src, (jlong*) dst, size / sizeof(jlong)); } else if (bits % sizeof(jint) == 0) { Copy::conjoint_jints_atomic((jint*) src, (jint*) dst, size / sizeof(jint)); } else if (bits % sizeof(jshort) == 0) { Copy::conjoint_jshorts_atomic((jshort*) src, (jshort*) dst, size / sizeof(jshort)); } else { // Not aligned, so no need to be atomic. Copy::conjoint_jbytes((void*) src, (void*) dst, size); } } // Fill bytes; larger units are filled atomically if everything is aligned. void Copy::fill_to_memory_atomic(void* to, size_t size, jubyte value) { address dst = (address) to; uintptr_t bits = (uintptr_t) to | (uintptr_t) size; if (bits % sizeof(jlong) == 0) { jlong fill = (julong)( (jubyte)value ); // zero-extend if (fill != 0) { fill += fill << 8; fill += fill << 16; fill += fill << 32; } //Copy::fill_to_jlongs_atomic((jlong*) dst, size / sizeof(jlong)); for (uintptr_t off = 0; off < size; off += sizeof(jlong)) { *(jlong*)(dst + off) = fill; } } else if (bits % sizeof(jint) == 0) { jint fill = (juint)( (jubyte)value ); // zero-extend if (fill != 0) { fill += fill << 8; fill += fill << 16; } //Copy::fill_to_jints_atomic((jint*) dst, size / sizeof(jint)); for (uintptr_t off = 0; off < size; off += sizeof(jint)) { *(jint*)(dst + off) = fill; } } else if (bits % sizeof(jshort) == 0) { jshort fill = (jushort)( (jubyte)value ); // zero-extend fill += fill << 8; //Copy::fill_to_jshorts_atomic((jshort*) dst, size / sizeof(jshort)); for (uintptr_t off = 0; off < size; off += sizeof(jshort)) { *(jshort*)(dst + off) = fill; } } else { // Not aligned, so no need to be atomic. Copy::fill_to_bytes(dst, size, value); } }