1/*
2 * Copyright (c) 2003, 2011, 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#ifndef SHARE_VM_UTILITIES_COPY_HPP
26#define SHARE_VM_UTILITIES_COPY_HPP
27
28#include "runtime/stubRoutines.hpp"
29
30// Assembly code for platforms that need it.
31extern "C" {
32  void _Copy_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
33  void _Copy_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
34
35  void _Copy_conjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
36  void _Copy_disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
37
38  void _Copy_aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
39  void _Copy_aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
40
41  void _Copy_conjoint_bytes(void* from, void* to, size_t count);
42
43  void _Copy_conjoint_bytes_atomic  (void*   from, void*   to, size_t count);
44  void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count);
45  void _Copy_conjoint_jints_atomic  (jint*   from, jint*   to, size_t count);
46  void _Copy_conjoint_jlongs_atomic (jlong*  from, jlong*  to, size_t count);
47  void _Copy_conjoint_oops_atomic   (oop*    from, oop*    to, size_t count);
48
49  void _Copy_arrayof_conjoint_bytes  (HeapWord* from, HeapWord* to, size_t count);
50  void _Copy_arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count);
51  void _Copy_arrayof_conjoint_jints  (HeapWord* from, HeapWord* to, size_t count);
52  void _Copy_arrayof_conjoint_jlongs (HeapWord* from, HeapWord* to, size_t count);
53  void _Copy_arrayof_conjoint_oops   (HeapWord* from, HeapWord* to, size_t count);
54}
55
56class Copy : AllStatic {
57 public:
58  // Block copy methods have four attributes.  We don't define all possibilities.
59  //   alignment: aligned to BytesPerLong
60  //   arrayof:   arraycopy operation with both operands aligned on the same
61  //              boundary as the first element of an array of the copy unit.
62  //              This is currently a HeapWord boundary on all platforms, except
63  //              for long and double arrays, which are aligned on an 8-byte
64  //              boundary on all platforms.
65  //              arraycopy operations are implicitly atomic on each array element.
66  //   overlap:   disjoint or conjoint.
67  //   copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).
68  //   atomicity: atomic or non-atomic on the copy unit.
69  //
70  // Names are constructed thusly:
71  //
72  //     [ 'aligned_' | 'arrayof_' ]
73  //     ('conjoint_' | 'disjoint_')
74  //     ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')
75  //     [ '_atomic' ]
76  //
77  // Except in the arrayof case, whatever the alignment is, we assume we can copy
78  // whole alignment units.  E.g., if BytesPerLong is 2x word alignment, an odd
79  // count may copy an extra word.  In the arrayof case, we are allowed to copy
80  // only the number of copy units specified.
81  //
82  // All callees check count for 0.
83  //
84
85  // HeapWords
86
87  // Word-aligned words,    conjoint, not atomic on each word
88  static void conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
89    assert_params_ok(from, to, LogHeapWordSize);
90    pd_conjoint_words(from, to, count);
91  }
92
93  // Word-aligned words,    disjoint, not atomic on each word
94  static void disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
95    assert_params_ok(from, to, LogHeapWordSize);
96    assert_disjoint(from, to, count);
97    pd_disjoint_words(from, to, count);
98  }
99
100  // Word-aligned words,    disjoint, atomic on each word
101  static void disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count) {
102    assert_params_ok(from, to, LogHeapWordSize);
103    assert_disjoint(from, to, count);
104    pd_disjoint_words_atomic(from, to, count);
105  }
106
107  // Object-aligned words,  conjoint, not atomic on each word
108  static void aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
109    assert_params_aligned(from, to);
110    pd_aligned_conjoint_words(from, to, count);
111  }
112
113  // Object-aligned words,  disjoint, not atomic on each word
114  static void aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
115    assert_params_aligned(from, to);
116    assert_disjoint(from, to, count);
117    pd_aligned_disjoint_words(from, to, count);
118  }
119
120  // bytes, jshorts, jints, jlongs, oops
121
122  // bytes,                 conjoint, not atomic on each byte (not that it matters)
123  static void conjoint_jbytes(void* from, void* to, size_t count) {
124    pd_conjoint_bytes(from, to, count);
125  }
126
127  // bytes,                 conjoint, atomic on each byte (not that it matters)
128  static void conjoint_jbytes_atomic(void* from, void* to, size_t count) {
129    pd_conjoint_bytes(from, to, count);
130  }
131
132  // jshorts,               conjoint, atomic on each jshort
133  static void conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
134    assert_params_ok(from, to, LogBytesPerShort);
135    pd_conjoint_jshorts_atomic(from, to, count);
136  }
137
138  // jints,                 conjoint, atomic on each jint
139  static void conjoint_jints_atomic(jint* from, jint* to, size_t count) {
140    assert_params_ok(from, to, LogBytesPerInt);
141    pd_conjoint_jints_atomic(from, to, count);
142  }
143
144  // jlongs,                conjoint, atomic on each jlong
145  static void conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
146    assert_params_ok(from, to, LogBytesPerLong);
147    pd_conjoint_jlongs_atomic(from, to, count);
148  }
149
150  // oops,                  conjoint, atomic on each oop
151  static void conjoint_oops_atomic(oop* from, oop* to, size_t count) {
152    assert_params_ok(from, to, LogBytesPerHeapOop);
153    pd_conjoint_oops_atomic(from, to, count);
154  }
155
156  // overloaded for UseCompressedOops
157  static void conjoint_oops_atomic(narrowOop* from, narrowOop* to, size_t count) {
158    assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");
159    assert_params_ok(from, to, LogBytesPerInt);
160    pd_conjoint_jints_atomic((jint*)from, (jint*)to, count);
161  }
162
163  // Copy a span of memory.  If the span is an integral number of aligned
164  // longs, words, or ints, copy those units atomically.
165  // The largest atomic transfer unit is 8 bytes, or the largest power
166  // of two which divides all of from, to, and size, whichever is smaller.
167  static void conjoint_memory_atomic(void* from, void* to, size_t size);
168
169  // bytes,                 conjoint array, atomic on each byte (not that it matters)
170  static void arrayof_conjoint_jbytes(HeapWord* from, HeapWord* to, size_t count) {
171    pd_arrayof_conjoint_bytes(from, to, count);
172  }
173
174  // jshorts,               conjoint array, atomic on each jshort
175  static void arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count) {
176    assert_params_ok(from, to, LogBytesPerShort);
177    pd_arrayof_conjoint_jshorts(from, to, count);
178  }
179
180  // jints,                 conjoint array, atomic on each jint
181  static void arrayof_conjoint_jints(HeapWord* from, HeapWord* to, size_t count) {
182    assert_params_ok(from, to, LogBytesPerInt);
183    pd_arrayof_conjoint_jints(from, to, count);
184  }
185
186  // jlongs,                conjoint array, atomic on each jlong
187  static void arrayof_conjoint_jlongs(HeapWord* from, HeapWord* to, size_t count) {
188    assert_params_ok(from, to, LogBytesPerLong);
189    pd_arrayof_conjoint_jlongs(from, to, count);
190  }
191
192  // oops,                  conjoint array, atomic on each oop
193  static void arrayof_conjoint_oops(HeapWord* from, HeapWord* to, size_t count) {
194    assert_params_ok(from, to, LogBytesPerHeapOop);
195    pd_arrayof_conjoint_oops(from, to, count);
196  }
197
198  // Known overlap methods
199
200  // Copy word-aligned words from higher to lower addresses, not atomic on each word
201  inline static void conjoint_words_to_lower(HeapWord* from, HeapWord* to, size_t byte_count) {
202    // byte_count is in bytes to check its alignment
203    assert_params_ok(from, to, LogHeapWordSize);
204    assert_byte_count_ok(byte_count, HeapWordSize);
205
206    size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
207    assert(to <= from || from + count <= to, "do not overwrite source data");
208
209    while (count-- > 0) {
210      *to++ = *from++;
211    }
212  }
213
214  // Copy word-aligned words from lower to higher addresses, not atomic on each word
215  inline static void conjoint_words_to_higher(HeapWord* from, HeapWord* to, size_t byte_count) {
216    // byte_count is in bytes to check its alignment
217    assert_params_ok(from, to, LogHeapWordSize);
218    assert_byte_count_ok(byte_count, HeapWordSize);
219
220    size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
221    assert(from <= to || to + count <= from, "do not overwrite source data");
222
223    from += count - 1;
224    to   += count - 1;
225    while (count-- > 0) {
226      *to-- = *from--;
227    }
228  }
229
230  // Fill methods
231
232  // Fill word-aligned words, not atomic on each word
233  // set_words
234  static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {
235    assert_params_ok(to, LogHeapWordSize);
236    pd_fill_to_words(to, count, value);
237  }
238
239  static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {
240    assert_params_aligned(to);
241    pd_fill_to_aligned_words(to, count, value);
242  }
243
244  // Fill bytes
245  static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {
246    pd_fill_to_bytes(to, count, value);
247  }
248
249  // Fill a span of memory.  If the span is an integral number of aligned
250  // longs, words, or ints, store to those units atomically.
251  // The largest atomic transfer unit is 8 bytes, or the largest power
252  // of two which divides both to and size, whichever is smaller.
253  static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);
254
255  // Zero-fill methods
256
257  // Zero word-aligned words, not atomic on each word
258  static void zero_to_words(HeapWord* to, size_t count) {
259    assert_params_ok(to, LogHeapWordSize);
260    pd_zero_to_words(to, count);
261  }
262
263  // Zero bytes
264  static void zero_to_bytes(void* to, size_t count) {
265    pd_zero_to_bytes(to, count);
266  }
267
268 private:
269  static bool params_disjoint(HeapWord* from, HeapWord* to, size_t count) {
270    if (from < to) {
271      return pointer_delta(to, from) >= count;
272    }
273    return pointer_delta(from, to) >= count;
274  }
275
276  // These methods raise a fatal if they detect a problem.
277
278  static void assert_disjoint(HeapWord* from, HeapWord* to, size_t count) {
279#ifdef ASSERT
280    if (!params_disjoint(from, to, count))
281      basic_fatal("source and dest overlap");
282#endif
283  }
284
285  static void assert_params_ok(void* from, void* to, intptr_t log_align) {
286#ifdef ASSERT
287    if (mask_bits((uintptr_t)from, right_n_bits(log_align)) != 0)
288      basic_fatal("not aligned");
289    if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
290      basic_fatal("not aligned");
291#endif
292  }
293
294  static void assert_params_ok(HeapWord* to, intptr_t log_align) {
295#ifdef ASSERT
296    if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
297      basic_fatal("not word aligned");
298#endif
299  }
300  static void assert_params_aligned(HeapWord* from, HeapWord* to) {
301#ifdef ASSERT
302    if (mask_bits((uintptr_t)from, BytesPerLong-1) != 0)
303      basic_fatal("not long aligned");
304    if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
305      basic_fatal("not long aligned");
306#endif
307  }
308
309  static void assert_params_aligned(HeapWord* to) {
310#ifdef ASSERT
311    if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
312      basic_fatal("not long aligned");
313#endif
314  }
315
316  static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {
317#ifdef ASSERT
318    if ((size_t)round_to(byte_count, unit_size) != byte_count) {
319      basic_fatal("byte count must be aligned");
320    }
321#endif
322  }
323
324  // Platform dependent implementations of the above methods.
325#ifdef TARGET_ARCH_x86
326# include "copy_x86.hpp"
327#endif
328#ifdef TARGET_ARCH_sparc
329# include "copy_sparc.hpp"
330#endif
331#ifdef TARGET_ARCH_zero
332# include "copy_zero.hpp"
333#endif
334#ifdef TARGET_ARCH_arm
335# include "copy_arm.hpp"
336#endif
337#ifdef TARGET_ARCH_ppc
338# include "copy_ppc.hpp"
339#endif
340
341};
342
343#endif // SHARE_VM_UTILITIES_COPY_HPP
344