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comparison src/share/vm/utilities/copy.cpp @ 0:a61af66fc99e jdk7-b24

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author duke
date Sat, 01 Dec 2007 00:00:00 +0000
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children c18cbe5936b8
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-1:000000000000 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.
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 }