1 /*
2 * Copyright (c) 2003, 2008, 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 // Assembly code for platforms that need it.
26 extern "C" {
27 void _Copy_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
28 void _Copy_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
29
30 void _Copy_conjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
31 void _Copy_disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
32
33 void _Copy_aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
34 void _Copy_aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
35
36 void _Copy_conjoint_bytes(void* from, void* to, size_t count);
37
38 void _Copy_conjoint_bytes_atomic (void* from, void* to, size_t count);
39 void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count);
40 void _Copy_conjoint_jints_atomic (jint* from, jint* to, size_t count);
41 void _Copy_conjoint_jlongs_atomic (jlong* from, jlong* to, size_t count);
42 void _Copy_conjoint_oops_atomic (oop* from, oop* to, size_t count);
43
44 void _Copy_arrayof_conjoint_bytes (HeapWord* from, HeapWord* to, size_t count);
45 void _Copy_arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count);
46 void _Copy_arrayof_conjoint_jints (HeapWord* from, HeapWord* to, size_t count);
47 void _Copy_arrayof_conjoint_jlongs (HeapWord* from, HeapWord* to, size_t count);
48 void _Copy_arrayof_conjoint_oops (HeapWord* from, HeapWord* to, size_t count);
49 }
50
51 class Copy : AllStatic {
52 public:
53 // Block copy methods have four attributes. We don't define all possibilities.
54 // alignment: aligned to BytesPerLong
55 // arrayof: arraycopy operation with both operands aligned on the same
56 // boundary as the first element of an array of the copy unit.
57 // This is currently a HeapWord boundary on all platforms, except
58 // for long and double arrays, which are aligned on an 8-byte
59 // boundary on all platforms.
60 // arraycopy operations are implicitly atomic on each array element.
61 // overlap: disjoint or conjoint.
62 // copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).
63 // atomicity: atomic or non-atomic on the copy unit.
64 //
65 // Names are constructed thusly:
66 //
67 // [ 'aligned_' | 'arrayof_' ]
68 // ('conjoint_' | 'disjoint_')
69 // ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')
70 // [ '_atomic' ]
71 //
72 // Except in the arrayof case, whatever the alignment is, we assume we can copy
73 // whole alignment units. E.g., if BytesPerLong is 2x word alignment, an odd
74 // count may copy an extra word. In the arrayof case, we are allowed to copy
75 // only the number of copy units specified.
76 //
77 // All callees check count for 0.
78 //
79
80 // HeapWords
81
82 // Word-aligned words, conjoint, not atomic on each word
83 static void conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
84 assert_params_ok(from, to, LogHeapWordSize);
85 pd_conjoint_words(from, to, count);
86 }
87
88 // Word-aligned words, disjoint, not atomic on each word
89 static void disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
90 assert_params_ok(from, to, LogHeapWordSize);
91 assert_disjoint(from, to, count);
92 pd_disjoint_words(from, to, count);
93 }
94
95 // Word-aligned words, disjoint, atomic on each word
96 static void disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count) {
97 assert_params_ok(from, to, LogHeapWordSize);
98 assert_disjoint(from, to, count);
99 pd_disjoint_words_atomic(from, to, count);
100 }
101
102 // Object-aligned words, conjoint, not atomic on each word
103 static void aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
104 assert_params_aligned(from, to);
105 pd_aligned_conjoint_words(from, to, count);
106 }
107
108 // Object-aligned words, disjoint, not atomic on each word
109 static void aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
110 assert_params_aligned(from, to);
111 assert_disjoint(from, to, count);
112 pd_aligned_disjoint_words(from, to, count);
113 }
114
115 // bytes, jshorts, jints, jlongs, oops
116
117 // bytes, conjoint, not atomic on each byte (not that it matters)
118 static void conjoint_jbytes(void* from, void* to, size_t count) {
119 pd_conjoint_bytes(from, to, count);
120 }
121
122 // bytes, conjoint, atomic on each byte (not that it matters)
123 static void conjoint_jbytes_atomic(void* from, void* to, size_t count) {
124 pd_conjoint_bytes(from, to, count);
125 }
126
127 // jshorts, conjoint, atomic on each jshort
128 static void conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
129 assert_params_ok(from, to, LogBytesPerShort);
130 pd_conjoint_jshorts_atomic(from, to, count);
131 }
132
133 // jints, conjoint, atomic on each jint
134 static void conjoint_jints_atomic(jint* from, jint* to, size_t count) {
135 assert_params_ok(from, to, LogBytesPerInt);
136 pd_conjoint_jints_atomic(from, to, count);
137 }
138
139 // jlongs, conjoint, atomic on each jlong
140 static void conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
141 assert_params_ok(from, to, LogBytesPerLong);
142 pd_conjoint_jlongs_atomic(from, to, count);
143 }
144
145 // oops, conjoint, atomic on each oop
146 static void conjoint_oops_atomic(oop* from, oop* to, size_t count) {
147 assert_params_ok(from, to, LogBytesPerHeapOop);
148 pd_conjoint_oops_atomic(from, to, count);
149 }
150
151 // overloaded for UseCompressedOops
152 static void conjoint_oops_atomic(narrowOop* from, narrowOop* to, size_t count) {
153 assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");
154 assert_params_ok(from, to, LogBytesPerInt);
155 pd_conjoint_jints_atomic((jint*)from, (jint*)to, count);
156 }
157
158 // Copy a span of memory. If the span is an integral number of aligned
159 // longs, words, or ints, copy those units atomically.
160 // The largest atomic transfer unit is 8 bytes, or the largest power
161 // of two which divides all of from, to, and size, whichever is smaller.
162 static void conjoint_memory_atomic(void* from, void* to, size_t size);
163
164 // bytes, conjoint array, atomic on each byte (not that it matters)
165 static void arrayof_conjoint_jbytes(HeapWord* from, HeapWord* to, size_t count) {
166 pd_arrayof_conjoint_bytes(from, to, count);
167 }
168
169 // jshorts, conjoint array, atomic on each jshort
170 static void arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count) {
171 assert_params_ok(from, to, LogBytesPerShort);
172 pd_arrayof_conjoint_jshorts(from, to, count);
173 }
174
175 // jints, conjoint array, atomic on each jint
176 static void arrayof_conjoint_jints(HeapWord* from, HeapWord* to, size_t count) {
177 assert_params_ok(from, to, LogBytesPerInt);
178 pd_arrayof_conjoint_jints(from, to, count);
179 }
180
181 // jlongs, conjoint array, atomic on each jlong
182 static void arrayof_conjoint_jlongs(HeapWord* from, HeapWord* to, size_t count) {
183 assert_params_ok(from, to, LogBytesPerLong);
184 pd_arrayof_conjoint_jlongs(from, to, count);
185 }
186
187 // oops, conjoint array, atomic on each oop
188 static void arrayof_conjoint_oops(HeapWord* from, HeapWord* to, size_t count) {
189 assert_params_ok(from, to, LogBytesPerHeapOop);
190 pd_arrayof_conjoint_oops(from, to, count);
191 }
192
193 // Known overlap methods
194
195 // Copy word-aligned words from higher to lower addresses, not atomic on each word
196 inline static void conjoint_words_to_lower(HeapWord* from, HeapWord* to, size_t byte_count) {
197 // byte_count is in bytes to check its alignment
198 assert_params_ok(from, to, LogHeapWordSize);
199 assert_byte_count_ok(byte_count, HeapWordSize);
200
201 size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
202 assert(to <= from || from + count <= to, "do not overwrite source data");
203
204 while (count-- > 0) {
205 *to++ = *from++;
206 }
207 }
208
209 // Copy word-aligned words from lower to higher addresses, not atomic on each word
210 inline static void conjoint_words_to_higher(HeapWord* from, HeapWord* to, size_t byte_count) {
211 // byte_count is in bytes to check its alignment
212 assert_params_ok(from, to, LogHeapWordSize);
213 assert_byte_count_ok(byte_count, HeapWordSize);
214
215 size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
216 assert(from <= to || to + count <= from, "do not overwrite source data");
217
218 from += count - 1;
219 to += count - 1;
220 while (count-- > 0) {
221 *to-- = *from--;
222 }
223 }
224
225 // Fill methods
226
227 // Fill word-aligned words, not atomic on each word
228 // set_words
229 static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {
230 assert_params_ok(to, LogHeapWordSize);
231 pd_fill_to_words(to, count, value);
232 }
233
234 static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {
235 assert_params_aligned(to);
236 pd_fill_to_aligned_words(to, count, value);
237 }
238
239 // Fill bytes
240 static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {
241 pd_fill_to_bytes(to, count, value);
242 }
243
244 // Fill a span of memory. If the span is an integral number of aligned
245 // longs, words, or ints, store to those units atomically.
246 // The largest atomic transfer unit is 8 bytes, or the largest power
247 // of two which divides both to and size, whichever is smaller.
248 static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);
249
250 // Zero-fill methods
251
252 // Zero word-aligned words, not atomic on each word
253 static void zero_to_words(HeapWord* to, size_t count) {
254 assert_params_ok(to, LogHeapWordSize);
255 pd_zero_to_words(to, count);
256 }
257
258 // Zero bytes
259 static void zero_to_bytes(void* to, size_t count) {
260 pd_zero_to_bytes(to, count);
261 }
262
263 private:
264 static bool params_disjoint(HeapWord* from, HeapWord* to, size_t count) {
265 if (from < to) {
266 return pointer_delta(to, from) >= count;
267 }
268 return pointer_delta(from, to) >= count;
269 }
270
271 // These methods raise a fatal if they detect a problem.
272
273 static void assert_disjoint(HeapWord* from, HeapWord* to, size_t count) {
274 #ifdef ASSERT
275 if (!params_disjoint(from, to, count))
276 basic_fatal("source and dest overlap");
277 #endif
278 }
279
280 static void assert_params_ok(void* from, void* to, intptr_t log_align) {
281 #ifdef ASSERT
282 if (mask_bits((uintptr_t)from, right_n_bits(log_align)) != 0)
283 basic_fatal("not aligned");
284 if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
285 basic_fatal("not aligned");
286 #endif
287 }
288
289 static void assert_params_ok(HeapWord* to, intptr_t log_align) {
290 #ifdef ASSERT
291 if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
292 basic_fatal("not word aligned");
293 #endif
294 }
295 static void assert_params_aligned(HeapWord* from, HeapWord* to) {
296 #ifdef ASSERT
297 if (mask_bits((uintptr_t)from, BytesPerLong-1) != 0)
298 basic_fatal("not long aligned");
299 if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
300 basic_fatal("not long aligned");
301 #endif
302 }
303
304 static void assert_params_aligned(HeapWord* to) {
305 #ifdef ASSERT
306 if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
307 basic_fatal("not long aligned");
308 #endif
309 }
310
311 static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {
312 #ifdef ASSERT
313 if ((size_t)round_to(byte_count, unit_size) != byte_count) {
314 basic_fatal("byte count must be aligned");
315 }
316 #endif
317 }
318
319 // Platform dependent implementations of the above methods.
320 #include "incls/_copy_pd.hpp.incl"
321 };