1 /* 2 * Copyright (c) 2006, 2007, 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 # include "incls/_precompiled.incl" 26 # include "incls/_copy.cpp.incl" 27 28 29 // Copy bytes; larger units are filled atomically if everything is aligned. 30 void Copy::conjoint_memory_atomic(void* from, void* to, size_t size) { 31 address src = (address) from; 32 address dst = (address) to; 33 uintptr_t bits = (uintptr_t) src | (uintptr_t) dst | (uintptr_t) size; 34 35 // (Note: We could improve performance by ignoring the low bits of size, 36 // and putting a short cleanup loop after each bulk copy loop. 37 // There are plenty of other ways to make this faster also, 38 // and it's a slippery slope. For now, let's keep this code simple 39 // since the simplicity helps clarify the atomicity semantics of 40 // this operation. There are also CPU-specific assembly versions 41 // which may or may not want to include such optimizations.) 42 43 if (bits % sizeof(jlong) == 0) { 44 Copy::conjoint_jlongs_atomic((jlong*) src, (jlong*) dst, size / sizeof(jlong)); 45 } else if (bits % sizeof(jint) == 0) { 46 Copy::conjoint_jints_atomic((jint*) src, (jint*) dst, size / sizeof(jint)); 47 } else if (bits % sizeof(jshort) == 0) { 48 Copy::conjoint_jshorts_atomic((jshort*) src, (jshort*) dst, size / sizeof(jshort)); 49 } else { 50 // Not aligned, so no need to be atomic. 51 Copy::conjoint_bytes((void*) src, (void*) dst, size); 52 } 53 } 54 55 56 // Fill bytes; larger units are filled atomically if everything is aligned. 57 void Copy::fill_to_memory_atomic(void* to, size_t size, jubyte value) { 58 address dst = (address) to; 59 uintptr_t bits = (uintptr_t) to | (uintptr_t) size; 60 if (bits % sizeof(jlong) == 0) { 61 jlong fill = (julong)( (jubyte)value ); // zero-extend 62 if (fill != 0) { 63 fill += fill << 8; 64 fill += fill << 16; 65 fill += fill << 32; 66 } 67 //Copy::fill_to_jlongs_atomic((jlong*) dst, size / sizeof(jlong)); 68 for (uintptr_t off = 0; off < size; off += sizeof(jlong)) { 69 *(jlong*)(dst + off) = fill; 70 } 71 } else if (bits % sizeof(jint) == 0) { 72 jint fill = (juint)( (jubyte)value ); // zero-extend 73 if (fill != 0) { 74 fill += fill << 8; 75 fill += fill << 16; 76 } 77 //Copy::fill_to_jints_atomic((jint*) dst, size / sizeof(jint)); 78 for (uintptr_t off = 0; off < size; off += sizeof(jint)) { 79 *(jint*)(dst + off) = fill; 80 } 81 } else if (bits % sizeof(jshort) == 0) { 82 jshort fill = (jushort)( (jubyte)value ); // zero-extend 83 fill += fill << 8; 84 //Copy::fill_to_jshorts_atomic((jshort*) dst, size / sizeof(jshort)); 85 for (uintptr_t off = 0; off < size; off += sizeof(jshort)) { 86 *(jshort*)(dst + off) = fill; 87 } 88 } else { 89 // Not aligned, so no need to be atomic. 90 Copy::fill_to_bytes(dst, size, value); 91 } 92 }