1/*
2 * Copyright (c) 2006, 2010, 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 "precompiled.hpp"
26#include "runtime/sharedRuntime.hpp"
27#include "utilities/copy.hpp"
28
29
30// Copy bytes; larger units are filled atomically if everything is aligned.
31void Copy::conjoint_memory_atomic(void* from, void* to, size_t size) {
32  address src = (address) from;
33  address dst = (address) to;
34  uintptr_t bits = (uintptr_t) src | (uintptr_t) dst | (uintptr_t) size;
35
36  // (Note:  We could improve performance by ignoring the low bits of size,
37  // and putting a short cleanup loop after each bulk copy loop.
38  // There are plenty of other ways to make this faster also,
39  // and it's a slippery slope.  For now, let's keep this code simple
40  // since the simplicity helps clarify the atomicity semantics of
41  // this operation.  There are also CPU-specific assembly versions
42  // which may or may not want to include such optimizations.)
43
44  if (bits % sizeof(jlong) == 0) {
45    Copy::conjoint_jlongs_atomic((jlong*) src, (jlong*) dst, size / sizeof(jlong));
46  } else if (bits % sizeof(jint) == 0) {
47    Copy::conjoint_jints_atomic((jint*) src, (jint*) dst, size / sizeof(jint));
48  } else if (bits % sizeof(jshort) == 0) {
49    Copy::conjoint_jshorts_atomic((jshort*) src, (jshort*) dst, size / sizeof(jshort));
50  } else {
51    // Not aligned, so no need to be atomic.
52    Copy::conjoint_jbytes((void*) src, (void*) dst, size);
53  }
54}
55
56
57// Fill bytes; larger units are filled atomically if everything is aligned.
58void Copy::fill_to_memory_atomic(void* to, size_t size, jubyte value) {
59  address dst = (address) to;
60  uintptr_t bits = (uintptr_t) to | (uintptr_t) size;
61  if (bits % sizeof(jlong) == 0) {
62    jlong fill = (julong)( (jubyte)value ); // zero-extend
63    if (fill != 0) {
64      fill += fill << 8;
65      fill += fill << 16;
66      fill += fill << 32;
67    }
68    //Copy::fill_to_jlongs_atomic((jlong*) dst, size / sizeof(jlong));
69    for (uintptr_t off = 0; off < size; off += sizeof(jlong)) {
70      *(jlong*)(dst + off) = fill;
71    }
72  } else if (bits % sizeof(jint) == 0) {
73    jint fill = (juint)( (jubyte)value ); // zero-extend
74    if (fill != 0) {
75      fill += fill << 8;
76      fill += fill << 16;
77    }
78    //Copy::fill_to_jints_atomic((jint*) dst, size / sizeof(jint));
79    for (uintptr_t off = 0; off < size; off += sizeof(jint)) {
80      *(jint*)(dst + off) = fill;
81    }
82  } else if (bits % sizeof(jshort) == 0) {
83    jshort fill = (jushort)( (jubyte)value ); // zero-extend
84    fill += fill << 8;
85    //Copy::fill_to_jshorts_atomic((jshort*) dst, size / sizeof(jshort));
86    for (uintptr_t off = 0; off < size; off += sizeof(jshort)) {
87      *(jshort*)(dst + off) = fill;
88    }
89  } else {
90    // Not aligned, so no need to be atomic.
91    Copy::fill_to_bytes(dst, size, value);
92  }
93}
94