copy.cpp revision 0:a61af66fc99e 
1/*
2 * Copyright 2006-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any 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.
30void 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.
57void 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}
93