1 /*
2 * Copyright (c) 2013, 2016, 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 package org.graalvm.compiler.hotspot.replacements.arraycopy;
24
25 import static org.graalvm.compiler.hotspot.GraalHotSpotVMConfig.INJECTED_VMCONFIG;
26 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.arrayBaseOffset;
27 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.arrayIndexScale;
28 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.layoutHelperHeaderSizeMask;
29 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.layoutHelperHeaderSizeShift;
30 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.layoutHelperLog2ElementSizeMask;
31 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.layoutHelperLog2ElementSizeShift;
32 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.runtime;
33 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.wordSize;
34 import static org.graalvm.compiler.nodes.NamedLocationIdentity.any;
35 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.NOT_FREQUENT_PROBABILITY;
36 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.probability;
37 import static org.graalvm.compiler.replacements.SnippetTemplate.DEFAULT_REPLACER;
38 import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntimeProvider.getArrayIndexScale;
39
40 import org.graalvm.compiler.api.replacements.Fold;
41 import org.graalvm.compiler.api.replacements.Snippet;
42 import org.graalvm.compiler.asm.NumUtil;
43 import org.graalvm.compiler.core.common.LocationIdentity;
44 import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
45 import org.graalvm.compiler.hotspot.phases.WriteBarrierAdditionPhase;
46 import org.graalvm.compiler.nodes.NamedLocationIdentity;
47 import org.graalvm.compiler.nodes.extended.UnsafeCopyNode;
48 import org.graalvm.compiler.nodes.extended.UnsafeLoadNode;
49 import org.graalvm.compiler.nodes.spi.LoweringTool;
50 import org.graalvm.compiler.replacements.SnippetTemplate;
51 import org.graalvm.compiler.replacements.SnippetTemplate.AbstractTemplates;
52 import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
53 import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
54 import org.graalvm.compiler.replacements.Snippets;
55 import org.graalvm.compiler.replacements.nodes.DirectObjectStoreNode;
56 import org.graalvm.compiler.word.ObjectAccess;
57 import org.graalvm.compiler.word.Unsigned;
58 import org.graalvm.compiler.word.Word;
59
60 import jdk.vm.ci.code.TargetDescription;
61 import jdk.vm.ci.meta.JavaKind;
62
63 /**
64 * As opposed to {@link ArrayCopySnippets}, these Snippets do <b>not</b> perform store checks.
65 */
66 public class UnsafeArrayCopySnippets implements Snippets {
67
68 private static final boolean supportsUnalignedMemoryAccess = runtime().getHostJVMCIBackend().getTarget().arch.supportsUnalignedMemoryAccess();
69
70 private static final JavaKind VECTOR_KIND = JavaKind.Long;
71 private static final long VECTOR_SIZE = getArrayIndexScale(VECTOR_KIND);
72
73 private static void vectorizedCopy(Object src, int srcPos, Object dest, int destPos, int length, JavaKind baseKind, LocationIdentity locationIdentity) {
74 int arrayBaseOffset = arrayBaseOffset(baseKind);
75 int elementSize = arrayIndexScale(baseKind);
76 long byteLength = (long) length * elementSize;
77 long srcOffset = (long) srcPos * elementSize;
78 long destOffset = (long) destPos * elementSize;
79
80 long preLoopBytes;
81 long mainLoopBytes;
82 long postLoopBytes;
83
84 // We can easily vectorize the loop if both offsets have the same alignment.
85 if (byteLength >= VECTOR_SIZE && (srcOffset % VECTOR_SIZE) == (destOffset % VECTOR_SIZE)) {
86 preLoopBytes = NumUtil.roundUp(arrayBaseOffset + srcOffset, VECTOR_SIZE) - (arrayBaseOffset + srcOffset);
87 postLoopBytes = (byteLength - preLoopBytes) % VECTOR_SIZE;
88 mainLoopBytes = byteLength - preLoopBytes - postLoopBytes;
89 } else {
90 // Does the architecture support unaligned memory accesses?
91 if (supportsUnalignedMemoryAccess) {
92 preLoopBytes = byteLength % VECTOR_SIZE;
93 mainLoopBytes = byteLength - preLoopBytes;
94 postLoopBytes = 0;
95 } else {
96 // No. Let's do element-wise copying.
97 preLoopBytes = byteLength;
98 mainLoopBytes = 0;
99 postLoopBytes = 0;
100 }
101 }
102
103 if (probability(NOT_FREQUENT_PROBABILITY, src == dest) && probability(NOT_FREQUENT_PROBABILITY, srcPos < destPos)) {
104 // bad aliased case
105 srcOffset += byteLength;
106 destOffset += byteLength;
107
108 // Post-loop
109 for (long i = 0; i < postLoopBytes; i += elementSize) {
110 srcOffset -= elementSize;
111 destOffset -= elementSize;
112 UnsafeCopyNode.copy(src, arrayBaseOffset + srcOffset, dest, arrayBaseOffset + destOffset, baseKind, locationIdentity);
113 }
114 // Main-loop
115 for (long i = 0; i < mainLoopBytes; i += VECTOR_SIZE) {
116 srcOffset -= VECTOR_SIZE;
117 destOffset -= VECTOR_SIZE;
118 UnsafeCopyNode.copy(src, arrayBaseOffset + srcOffset, dest, arrayBaseOffset + destOffset, VECTOR_KIND, locationIdentity);
119 }
120 // Pre-loop
121 for (long i = 0; i < preLoopBytes; i += elementSize) {
122 srcOffset -= elementSize;
123 destOffset -= elementSize;
124 UnsafeCopyNode.copy(src, arrayBaseOffset + srcOffset, dest, arrayBaseOffset + destOffset, baseKind, locationIdentity);
125 }
126 } else {
127 // Pre-loop
128 for (long i = 0; i < preLoopBytes; i += elementSize) {
129 UnsafeCopyNode.copy(src, arrayBaseOffset + srcOffset, dest, arrayBaseOffset + destOffset, baseKind, locationIdentity);
130 srcOffset += elementSize;
131 destOffset += elementSize;
132 }
133 // Main-loop
134 for (long i = 0; i < mainLoopBytes; i += VECTOR_SIZE) {
135 UnsafeCopyNode.copy(src, arrayBaseOffset + srcOffset, dest, arrayBaseOffset + destOffset, VECTOR_KIND, locationIdentity);
136 srcOffset += VECTOR_SIZE;
137 destOffset += VECTOR_SIZE;
138 }
139 // Post-loop
140 for (long i = 0; i < postLoopBytes; i += elementSize) {
141 UnsafeCopyNode.copy(src, arrayBaseOffset + srcOffset, dest, arrayBaseOffset + destOffset, baseKind, locationIdentity);
142 srcOffset += elementSize;
143 destOffset += elementSize;
144 }
145 }
146 }
147
148 @Fold
149 static LocationIdentity getArrayLocation(JavaKind kind) {
150 return NamedLocationIdentity.getArrayLocation(kind);
151 }
152
153 @Snippet
154 public static void arraycopyByte(byte[] src, int srcPos, byte[] dest, int destPos, int length) {
155 JavaKind kind = JavaKind.Byte;
156 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
157 }
158
159 @Snippet
160 public static void arraycopyBoolean(boolean[] src, int srcPos, boolean[] dest, int destPos, int length) {
161 JavaKind kind = JavaKind.Boolean;
162 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
163 }
164
165 @Snippet
166 public static void arraycopyChar(char[] src, int srcPos, char[] dest, int destPos, int length) {
167 JavaKind kind = JavaKind.Char;
168 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
169 }
170
171 @Snippet
172 public static void arraycopyShort(short[] src, int srcPos, short[] dest, int destPos, int length) {
173 JavaKind kind = JavaKind.Short;
174 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
175 }
176
177 @Snippet
178 public static void arraycopyInt(int[] src, int srcPos, int[] dest, int destPos, int length) {
179 JavaKind kind = JavaKind.Int;
180 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
181 }
182
183 @Snippet
184 public static void arraycopyFloat(float[] src, int srcPos, float[] dest, int destPos, int length) {
185 JavaKind kind = JavaKind.Float;
186 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
187 }
188
189 @Snippet
190 public static void arraycopyLong(long[] src, int srcPos, long[] dest, int destPos, int length) {
191 JavaKind kind = JavaKind.Long;
192 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
193 }
194
195 @Snippet
196 public static void arraycopyDouble(double[] src, int srcPos, double[] dest, int destPos, int length) {
197 JavaKind kind = JavaKind.Double;
198 /*
199 * TODO atomicity problem on 32-bit architectures: The JVM spec requires double values to be
200 * copied atomically, but not long values. For example, on Intel 32-bit this code is not
201 * atomic as long as the vector kind remains Kind.Long.
202 */
203 vectorizedCopy(src, srcPos, dest, destPos, length, kind, getArrayLocation(kind));
204 }
205
206 /**
207 * For this kind, Object, we want to avoid write barriers between writes, but instead have them
208 * at the end of the snippet. This is done by using {@link DirectObjectStoreNode}, and rely on
209 * {@link WriteBarrierAdditionPhase} to put write barriers after the {@link UnsafeArrayCopyNode}
210 * with kind Object.
211 */
212 @Snippet
213 public static void arraycopyObject(Object[] src, int srcPos, Object[] dest, int destPos, int length) {
214 JavaKind kind = JavaKind.Object;
215 final int scale = arrayIndexScale(kind);
216 int arrayBaseOffset = arrayBaseOffset(kind);
217 LocationIdentity arrayLocation = getArrayLocation(kind);
218 if (src == dest && srcPos < destPos) { // bad aliased case
219 long start = (long) (length - 1) * scale;
220 for (long i = start; i >= 0; i -= scale) {
221 Object a = UnsafeLoadNode.load(src, arrayBaseOffset + i + (long) srcPos * scale, kind, arrayLocation);
222 DirectObjectStoreNode.storeObject(dest, arrayBaseOffset, i + (long) destPos * scale, a, getArrayLocation(kind), kind);
223 }
224 } else {
225 long end = (long) length * scale;
226 for (long i = 0; i < end; i += scale) {
227 Object a = UnsafeLoadNode.load(src, arrayBaseOffset + i + (long) srcPos * scale, kind, arrayLocation);
228 DirectObjectStoreNode.storeObject(dest, arrayBaseOffset, i + (long) destPos * scale, a, getArrayLocation(kind), kind);
229 }
230 }
231 }
232
233 @Snippet
234 public static void arraycopyPrimitive(Object src, int srcPos, Object dest, int destPos, int length, int layoutHelper) {
235 int log2ElementSize = (layoutHelper >> layoutHelperLog2ElementSizeShift(INJECTED_VMCONFIG)) & layoutHelperLog2ElementSizeMask(INJECTED_VMCONFIG);
236 int headerSize = (layoutHelper >> layoutHelperHeaderSizeShift(INJECTED_VMCONFIG)) & layoutHelperHeaderSizeMask(INJECTED_VMCONFIG);
237
238 Unsigned vectorSize = Word.unsigned(VECTOR_SIZE);
239 Unsigned srcOffset = Word.unsigned(srcPos).shiftLeft(log2ElementSize).add(headerSize);
240 Unsigned destOffset = Word.unsigned(destPos).shiftLeft(log2ElementSize).add(headerSize);
241 Unsigned destStart = destOffset;
242 Unsigned destEnd = destOffset.add(Word.unsigned(length).shiftLeft(log2ElementSize));
243
244 Unsigned destVectorEnd = null;
245 Unsigned nonVectorBytes = null;
246 Unsigned sizeInBytes = Word.unsigned(length).shiftLeft(log2ElementSize);
247 if (supportsUnalignedMemoryAccess) {
248 nonVectorBytes = sizeInBytes.unsignedRemainder(vectorSize);
249 destVectorEnd = destEnd;
250 } else {
251 boolean inPhase = srcOffset.and((int) VECTOR_SIZE - 1).equal(destOffset.and((int) VECTOR_SIZE - 1));
252 boolean hasAtLeastOneVector = sizeInBytes.aboveOrEqual(vectorSize);
253 // We must have at least one full vector, otherwise we must copy each byte separately
254 if (hasAtLeastOneVector && inPhase) { // If in phase, we can vectorize
255 nonVectorBytes = vectorSize.subtract(destStart.unsignedRemainder(vectorSize));
256 } else { // fallback is byte-wise
257 nonVectorBytes = sizeInBytes;
258 }
259 destVectorEnd = destEnd.subtract(destEnd.unsignedRemainder(vectorSize));
260 }
261
262 Unsigned destNonVectorEnd = destStart.add(nonVectorBytes);
263 while (destOffset.belowThan(destNonVectorEnd)) {
264 ObjectAccess.writeByte(dest, destOffset, ObjectAccess.readByte(src, srcOffset, any()), any());
265 destOffset = destOffset.add(1);
266 srcOffset = srcOffset.add(1);
267 }
268 // Unsigned destVectorEnd = destEnd.subtract(destEnd.unsignedRemainder(8));
269 while (destOffset.belowThan(destVectorEnd)) {
270 ObjectAccess.writeWord(dest, destOffset, ObjectAccess.readWord(src, srcOffset, any()), any());
271 destOffset = destOffset.add(wordSize());
272 srcOffset = srcOffset.add(wordSize());
273 }
274 // Do the last bytes each when it is required to have absolute alignment.
275 while (!supportsUnalignedMemoryAccess && destOffset.belowThan(destEnd)) {
276 ObjectAccess.writeByte(dest, destOffset, ObjectAccess.readByte(src, srcOffset, any()), any());
277 destOffset = destOffset.add(1);
278 srcOffset = srcOffset.add(1);
279 }
280 }
281
282 public static class Templates extends AbstractTemplates {
283
284 private final SnippetInfo[] arraycopySnippets;
285 private final SnippetInfo genericPrimitiveSnippet;
286
287 public Templates(HotSpotProviders providers, TargetDescription target) {
288 super(providers, providers.getSnippetReflection(), target);
289
290 arraycopySnippets = new SnippetInfo[JavaKind.values().length];
291 arraycopySnippets[JavaKind.Boolean.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyBoolean");
292 arraycopySnippets[JavaKind.Byte.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyByte");
293 arraycopySnippets[JavaKind.Short.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyShort");
294 arraycopySnippets[JavaKind.Char.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyChar");
295 arraycopySnippets[JavaKind.Int.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyInt");
296 arraycopySnippets[JavaKind.Long.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyLong");
297 arraycopySnippets[JavaKind.Float.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyFloat");
298 arraycopySnippets[JavaKind.Double.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyDouble");
299 arraycopySnippets[JavaKind.Object.ordinal()] = snippet(UnsafeArrayCopySnippets.class, "arraycopyObject");
300
301 genericPrimitiveSnippet = snippet(UnsafeArrayCopySnippets.class, "arraycopyPrimitive");
302 }
303
304 public void lower(UnsafeArrayCopyNode node, LoweringTool tool) {
305 JavaKind elementKind = node.getElementKind();
306 SnippetInfo snippet;
307 if (elementKind == null) {
308 // primitive array of unknown kind
309 snippet = genericPrimitiveSnippet;
310 } else {
311 snippet = arraycopySnippets[elementKind.ordinal()];
312 assert snippet != null : "arraycopy snippet for " + elementKind.name() + " not found";
313 }
314
315 Arguments args = new Arguments(snippet, node.graph().getGuardsStage(), tool.getLoweringStage());
316 node.addSnippetArguments(args);
317
318 SnippetTemplate template = template(args);
319 template.instantiate(providers.getMetaAccess(), node, DEFAULT_REPLACER, args);
320 }
321 }
322 }