--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/util/UnsafeArrayTypeReader.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,232 @@
+/*
+ * Copyright (c) 2015, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.graalvm.compiler.core.common.util;
+
+import static org.graalvm.compiler.core.common.util.UnsafeAccess.UNSAFE;
+import sun.misc.Unsafe;
+
+/**
+ * Provides low-level read access from a byte[] array for signed and unsigned values of size 1, 2,
+ * 4, and 8 bytes.
+ *
+ * The class can either be instantiated for sequential access to the byte[] array; or static methods
+ * can be used to read values without the overhead of creating an instance.
+ *
+ * The flag {@code supportsUnalignedMemoryAccess} must be set according to the capabilities of the
+ * hardware architecture: the value {@code true} allows more efficient memory access on
+ * architectures that support unaligned memory accesses; the value {@code false} is the safe
+ * fallback that works on every hardware.
+ */
+public abstract class UnsafeArrayTypeReader implements TypeReader {
+
+ public static int getS1(byte[] data, long byteIndex) {
+ return UNSAFE.getByte(data, readOffset(data, byteIndex, Byte.BYTES));
+ }
+
+ public static int getU1(byte[] data, long byteIndex) {
+ return UNSAFE.getByte(data, readOffset(data, byteIndex, Byte.BYTES)) & 0xFF;
+ }
+
+ public static int getS2(byte[] data, long byteIndex, boolean supportsUnalignedMemoryAccess) {
+ if (supportsUnalignedMemoryAccess) {
+ return UnalignedUnsafeArrayTypeReader.getS2(data, byteIndex);
+ } else {
+ return AlignedUnsafeArrayTypeReader.getS2(data, byteIndex);
+ }
+ }
+
+ public static int getU2(byte[] data, long byteIndex, boolean supportsUnalignedMemoryAccess) {
+ return getS2(data, byteIndex, supportsUnalignedMemoryAccess) & 0xFFFF;
+ }
+
+ public static int getS4(byte[] data, long byteIndex, boolean supportsUnalignedMemoryAccess) {
+ if (supportsUnalignedMemoryAccess) {
+ return UnalignedUnsafeArrayTypeReader.getS4(data, byteIndex);
+ } else {
+ return AlignedUnsafeArrayTypeReader.getS4(data, byteIndex);
+ }
+ }
+
+ public static long getU4(byte[] data, long byteIndex, boolean supportsUnalignedMemoryAccess) {
+ return getS4(data, byteIndex, supportsUnalignedMemoryAccess) & 0xFFFFFFFFL;
+ }
+
+ public static long getS8(byte[] data, long byteIndex, boolean supportsUnalignedMemoryAccess) {
+ if (supportsUnalignedMemoryAccess) {
+ return UnalignedUnsafeArrayTypeReader.getS8(data, byteIndex);
+ } else {
+ return AlignedUnsafeArrayTypeReader.getS8(data, byteIndex);
+ }
+ }
+
+ protected static long readOffset(byte[] data, long byteIndex, int numBytes) {
+ assert byteIndex >= 0;
+ assert numBytes > 0;
+ assert byteIndex + numBytes <= data.length;
+ assert Unsafe.ARRAY_BYTE_INDEX_SCALE == 1;
+
+ return byteIndex + Unsafe.ARRAY_BYTE_BASE_OFFSET;
+ }
+
+ public static UnsafeArrayTypeReader create(byte[] data, long byteIndex, boolean supportsUnalignedMemoryAccess) {
+ if (supportsUnalignedMemoryAccess) {
+ return new UnalignedUnsafeArrayTypeReader(data, byteIndex);
+ } else {
+ return new AlignedUnsafeArrayTypeReader(data, byteIndex);
+ }
+ }
+
+ protected final byte[] data;
+ protected long byteIndex;
+
+ protected UnsafeArrayTypeReader(byte[] data, long byteIndex) {
+ this.data = data;
+ this.byteIndex = byteIndex;
+ }
+
+ @Override
+ public long getByteIndex() {
+ return byteIndex;
+ }
+
+ @Override
+ public void setByteIndex(long byteIndex) {
+ this.byteIndex = byteIndex;
+ }
+
+ @Override
+ public final int getS1() {
+ int result = getS1(data, byteIndex);
+ byteIndex += Byte.BYTES;
+ return result;
+ }
+
+ @Override
+ public final int getU1() {
+ int result = getU1(data, byteIndex);
+ byteIndex += Byte.BYTES;
+ return result;
+ }
+
+ @Override
+ public final int getU2() {
+ return getS2() & 0xFFFF;
+ }
+
+ @Override
+ public final long getU4() {
+ return getS4() & 0xFFFFFFFFL;
+ }
+}
+
+final class UnalignedUnsafeArrayTypeReader extends UnsafeArrayTypeReader {
+ protected static int getS2(byte[] data, long byteIndex) {
+ return UNSAFE.getShort(data, readOffset(data, byteIndex, Short.BYTES));
+ }
+
+ protected static int getS4(byte[] data, long byteIndex) {
+ return UNSAFE.getInt(data, readOffset(data, byteIndex, Integer.BYTES));
+ }
+
+ protected static long getS8(byte[] data, long byteIndex) {
+ return UNSAFE.getLong(data, readOffset(data, byteIndex, Long.BYTES));
+ }
+
+ protected UnalignedUnsafeArrayTypeReader(byte[] data, long byteIndex) {
+ super(data, byteIndex);
+ }
+
+ @Override
+ public int getS2() {
+ int result = getS2(data, byteIndex);
+ byteIndex += Short.BYTES;
+ return result;
+ }
+
+ @Override
+ public int getS4() {
+ int result = getS4(data, byteIndex);
+ byteIndex += Integer.BYTES;
+ return result;
+ }
+
+ @Override
+ public long getS8() {
+ long result = getS8(data, byteIndex);
+ byteIndex += Long.BYTES;
+ return result;
+ }
+}
+
+class AlignedUnsafeArrayTypeReader extends UnsafeArrayTypeReader {
+ protected static int getS2(byte[] data, long byteIndex) {
+ long offset = readOffset(data, byteIndex, Short.BYTES);
+ return ((UNSAFE.getByte(data, offset + 0) & 0xFF) << 0) | //
+ (UNSAFE.getByte(data, offset + 1) << 8);
+ }
+
+ protected static int getS4(byte[] data, long byteIndex) {
+ long offset = readOffset(data, byteIndex, Integer.BYTES);
+ return ((UNSAFE.getByte(data, offset + 0) & 0xFF) << 0) | //
+ ((UNSAFE.getByte(data, offset + 1) & 0xFF) << 8) | //
+ ((UNSAFE.getByte(data, offset + 2) & 0xFF) << 16) | //
+ (UNSAFE.getByte(data, offset + 3) << 24);
+ }
+
+ protected static long getS8(byte[] data, long byteIndex) {
+ long offset = readOffset(data, byteIndex, Long.BYTES);
+ return ((long) ((UNSAFE.getByte(data, offset + 0) & 0xFF)) << 0) | //
+ ((long) ((UNSAFE.getByte(data, offset + 1) & 0xFF)) << 8) | //
+ ((long) ((UNSAFE.getByte(data, offset + 2) & 0xFF)) << 16) | //
+ ((long) ((UNSAFE.getByte(data, offset + 3) & 0xFF)) << 24) | //
+ ((long) ((UNSAFE.getByte(data, offset + 4) & 0xFF)) << 32) | //
+ ((long) ((UNSAFE.getByte(data, offset + 5) & 0xFF)) << 40) | //
+ ((long) ((UNSAFE.getByte(data, offset + 6) & 0xFF)) << 48) | //
+ ((long) (UNSAFE.getByte(data, offset + 7)) << 56);
+ }
+
+ protected AlignedUnsafeArrayTypeReader(byte[] data, long byteIndex) {
+ super(data, byteIndex);
+ }
+
+ @Override
+ public int getS2() {
+ int result = getS2(data, byteIndex);
+ byteIndex += Short.BYTES;
+ return result;
+ }
+
+ @Override
+ public int getS4() {
+ int result = getS4(data, byteIndex);
+ byteIndex += Integer.BYTES;
+ return result;
+ }
+
+ @Override
+ public long getS8() {
+ long result = getS8(data, byteIndex);
+ byteIndex += Long.BYTES;
+ return result;
+ }
+}