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 * 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

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 */

/**

 * @test

 * @bug 8078497

 * @summary Tests correct alignment of vectors with loop invariant offset.

 * @modules java.base/jdk.internal.misc

 * @library /test/lib

 * @run main compiler.loopopts.superword.TestVectorizationWithInvariant

 */

package compiler.loopopts.superword;

import jdk.internal.misc.Unsafe;

public class TestVectorizationWithInvariant {

    private static Unsafe unsafe;

    private static final long BYTE_ARRAY_OFFSET;

    private static final long CHAR_ARRAY_OFFSET;

    static {

        BYTE_ARRAY_OFFSET = unsafe.arrayBaseOffset(byte[].class);

        CHAR_ARRAY_OFFSET = unsafe.arrayBaseOffset(char[].class);

    }

    public static void main(String[] args) throws Exception {

        byte[] byte_array1 = new byte[1000];

        byte[] byte_array2 = new byte[1000];

        char[] char_array = new char[1000];

        for (int i = 0; i < 20_000; ++i) {

            copyByteToChar(byte_array1, byte_array2, char_array, 1);

            copyCharToByte(char_array, byte_array1, 1);

            copyCharToByteAligned(char_array, byte_array1);

            copyCharToByteUnaligned(char_array, byte_array1);

        }

    }

    /*

     * Copy multiple consecutive chars from a byte array to a given offset in a char array

     * to trigger C2's superword optimization. The offset in the byte array is independent

     * of the loop induction variable and can be set to an arbitrary value. It may then not

     * be possible to both align the LoadUS and the StoreC operations. Therefore, vectorization

     * should only be done in this case if unaligned memory accesses are allowed.

     */

    public static void copyByteToChar(byte[] src1, byte[] src2, char[] dst, int off) {

        off = (int) BYTE_ARRAY_OFFSET + (off << 1);

        byte[] src = src1;

        for (int i = (int) CHAR_ARRAY_OFFSET; i < 100; i = i + 8) {

            // Copy 8 chars from src to dst

            unsafe.putChar(dst, i + 0, unsafe.getChar(src, off + 0));

            unsafe.putChar(dst, i + 2, unsafe.getChar(src, off + 2));

            unsafe.putChar(dst, i + 4, unsafe.getChar(src, off + 4));

            unsafe.putChar(dst, i + 6, unsafe.getChar(src, off + 6));

            unsafe.putChar(dst, i + 8, unsafe.getChar(src, off + 8));

            unsafe.putChar(dst, i + 10, unsafe.getChar(src, off + 10));

            unsafe.putChar(dst, i + 12, unsafe.getChar(src, off + 12));

            unsafe.putChar(dst, i + 14, unsafe.getChar(src, off + 14));

            // Prevent loop invariant code motion of char read.

            src = (src == src1) ? src2 : src1;

        }

    }

    /*

     * Copy multiple consecutive chars from a char array to a given offset in a byte array

     * to trigger C2's superword optimization. Checks for similar problems as 'copyByteToChar'.

     */

    public static void copyCharToByte(char[] src, byte[] dst, int off) {

        off = (int) BYTE_ARRAY_OFFSET + (off << 1);

        for (int i = 0; i < 100; i = i + 8) {

            // Copy 8 chars from src to dst

            unsafe.putChar(dst, off + 0, src[i + 0]);

            unsafe.putChar(dst, off + 2, src[i + 1]);

            unsafe.putChar(dst, off + 4, src[i + 2]);

            unsafe.putChar(dst, off + 6, src[i + 3]);

            unsafe.putChar(dst, off + 8, src[i + 4]);

            unsafe.putChar(dst, off + 10, src[i + 5]);

            unsafe.putChar(dst, off + 12, src[i + 6]);

            unsafe.putChar(dst, off + 14, src[i + 7]);

        }

    }

    /*

     * Variant of copyCharToByte with a constant destination array offset.

     * The loop should always be vectorized because both the LoadUS and StoreC

     * operations can be aligned.

     */

    public static void copyCharToByteAligned(char[] src, byte[] dst) {

        final int off = (int) BYTE_ARRAY_OFFSET;

        for (int i = 8; i < 100; i = i + 8) {

            // Copy 8 chars from src to dst

            unsafe.putChar(dst, off + 0, src[i + 0]);

            unsafe.putChar(dst, off + 2, src[i + 1]);

            unsafe.putChar(dst, off + 4, src[i + 2]);

            unsafe.putChar(dst, off + 6, src[i + 3]);

            unsafe.putChar(dst, off + 8, src[i + 4]);

            unsafe.putChar(dst, off + 10, src[i + 5]);

            unsafe.putChar(dst, off + 12, src[i + 6]);

            unsafe.putChar(dst, off + 14, src[i + 7]);

        }

    }

    /*

     * Variant of copyCharToByte with a constant destination array offset. The

     * loop should only be vectorized if unaligned memory operations are allowed

     * because not both the LoadUS and the StoreC can be aligned.

     */

    public static void copyCharToByteUnaligned(char[] src, byte[] dst) {

        final int off = (int) BYTE_ARRAY_OFFSET + 2;

        for (int i = 0; i < 100; i = i + 8) {

            // Copy 8 chars from src to dst

            unsafe.putChar(dst, off + 0, src[i + 0]);

            unsafe.putChar(dst, off + 2, src[i + 1]);

            unsafe.putChar(dst, off + 4, src[i + 2]);

            unsafe.putChar(dst, off + 6, src[i + 3]);

            unsafe.putChar(dst, off + 8, src[i + 4]);

            unsafe.putChar(dst, off + 10, src[i + 5]);

            unsafe.putChar(dst, off + 12, src[i + 6]);

            unsafe.putChar(dst, off + 14, src[i + 7]);

        }

    }

}