/*

 * Copyright (c) 2017, 2019, 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.replacements.amd64;

import jdk.vm.ci.meta.DeoptimizationAction;

import jdk.vm.ci.meta.DeoptimizationReason;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.MetaAccessProvider;

import org.graalvm.compiler.api.replacements.ClassSubstitution;

import org.graalvm.compiler.api.replacements.Fold;

import org.graalvm.compiler.api.replacements.Fold.InjectedParameter;

import org.graalvm.compiler.api.replacements.MethodSubstitution;

import org.graalvm.compiler.nodes.DeoptimizeNode;

import org.graalvm.compiler.replacements.ReplacementsUtil;

import org.graalvm.compiler.replacements.StringUTF16Substitutions;

import org.graalvm.compiler.replacements.nodes.ArrayCompareToNode;

import org.graalvm.compiler.replacements.nodes.ArrayRegionEqualsNode;

import org.graalvm.compiler.word.Word;

import jdk.internal.vm.compiler.word.Pointer;

// JaCoCo Exclude

/**

 * Substitutions for {@code java.lang.StringUTF16} methods.

 * <p>

 * Since JDK 9.

 */

@ClassSubstitution(className = "java.lang.StringUTF16", optional = true)

public class AMD64StringUTF16Substitutions {

    @Fold

    static int byteArrayBaseOffset(@InjectedParameter MetaAccessProvider metaAccess) {

        return metaAccess.getArrayBaseOffset(JavaKind.Byte);

    }

    @Fold

    static int byteArrayIndexScale(@InjectedParameter MetaAccessProvider metaAccess) {

        return metaAccess.getArrayIndexScale(JavaKind.Byte);

    }

    @Fold

    static int charArrayBaseOffset(@InjectedParameter MetaAccessProvider metaAccess) {

        return metaAccess.getArrayBaseOffset(JavaKind.Char);

    }

    @Fold

    static int charArrayIndexScale(@InjectedParameter MetaAccessProvider metaAccess) {

        return metaAccess.getArrayIndexScale(JavaKind.Char);

    }

    /**

     * Marker value for the {@link InjectedParameter} injected parameter.

     */

    static final MetaAccessProvider INJECTED = null;

    public static int length(byte[] value) {

        return value.length >> 1;

    }

    /**

     * @param value is char[]

     * @param other is char[]

     */

    @MethodSubstitution

    public static int compareTo(byte[] value, byte[] other) {

        return ArrayCompareToNode.compareTo(value, other, value.length, other.length, JavaKind.Char, JavaKind.Char);

    }

    /**

     * @param value is char[]

     * @param other is byte[]

     */

    @MethodSubstitution

    public static int compareToLatin1(byte[] value, byte[] other) {

        /*

         * Swapping array arguments because intrinsic expects order to be byte[]/char[] but kind

         * arguments stay in original order.

         */

        return ArrayCompareToNode.compareTo(other, value, other.length, value.length, JavaKind.Char, JavaKind.Byte);

    }

    @MethodSubstitution

    public static int indexOfCharUnsafe(byte[] value, int ch, int fromIndex, int max) {

        return AMD64ArrayIndexOf.indexOf1Char(value, max, fromIndex, (char) ch);

    }

    private static Word pointer(byte[] target) {

        return Word.objectToTrackedPointer(target).add(byteArrayBaseOffset(INJECTED));

    }

    private static Word charOffsetPointer(byte[] value, int offset) {

        return pointer(value).add(offset * charArrayIndexScale(INJECTED));

    }

    @MethodSubstitution

    public static int indexOfUnsafe(byte[] source, int sourceCount, byte[] target, int targetCount, int fromIndex) {

        ReplacementsUtil.runtimeAssert(fromIndex >= 0, "StringUTF16.indexOfUnsafe invalid args: fromIndex negative");

        ReplacementsUtil.runtimeAssert(targetCount > 0, "StringUTF16.indexOfUnsafe invalid args: targetCount <= 0");

        ReplacementsUtil.runtimeAssert(targetCount <= length(target), "StringUTF16.indexOfUnsafe invalid args: targetCount > length(target)");

        ReplacementsUtil.runtimeAssert(sourceCount >= targetCount, "StringUTF16.indexOfUnsafe invalid args: sourceCount < targetCount");

        if (targetCount == 1) {

            return AMD64ArrayIndexOf.indexOf1Char(source, sourceCount, fromIndex, StringUTF16Substitutions.getChar(target, 0));

        } else {

            int haystackLength = sourceCount - (targetCount - 2);

            int offset = fromIndex;

            while (offset < haystackLength) {

                int indexOfResult = AMD64ArrayIndexOf.indexOfTwoConsecutiveChars(source, haystackLength, offset, StringUTF16Substitutions.getChar(target, 0),

                                StringUTF16Substitutions.getChar(target, 1));

                if (indexOfResult < 0) {

                    return -1;

                }

                offset = indexOfResult;

                Pointer cmpSourcePointer = charOffsetPointer(source, offset);

                Pointer targetPointer = pointer(target);

                if (targetCount == 2 || ArrayRegionEqualsNode.regionEquals(cmpSourcePointer, targetPointer, targetCount, JavaKind.Char)) {

                    return offset;

                }

                offset++;

            }

            return -1;

        }

    }

    @MethodSubstitution

    public static int indexOfLatin1Unsafe(byte[] source, int sourceCount, byte[] target, int targetCount, int fromIndex) {

        ReplacementsUtil.runtimeAssert(fromIndex >= 0, "StringUTF16.indexOfLatin1Unsafe invalid args: fromIndex negative");

        ReplacementsUtil.runtimeAssert(targetCount > 0, "StringUTF16.indexOfLatin1Unsafe invalid args: targetCount <= 0");

        ReplacementsUtil.runtimeAssert(targetCount <= target.length, "StringUTF16.indexOfLatin1Unsafe invalid args: targetCount > length(target)");

        ReplacementsUtil.runtimeAssert(sourceCount >= targetCount, "StringUTF16.indexOfLatin1Unsafe invalid args: sourceCount < targetCount");

        if (targetCount == 1) {

            return AMD64ArrayIndexOf.indexOf1Char(source, sourceCount, fromIndex, (char) Byte.toUnsignedInt(target[0]));

        } else {

            int haystackLength = sourceCount - (targetCount - 2);

            int offset = fromIndex;

            while (offset < haystackLength) {

                int indexOfResult = AMD64ArrayIndexOf.indexOfTwoConsecutiveChars(source, haystackLength, offset, (char) Byte.toUnsignedInt(target[0]), (char) Byte.toUnsignedInt(target[1]));

                if (indexOfResult < 0) {

                    return -1;

                }

                offset = indexOfResult;

                Pointer cmpSourcePointer = charOffsetPointer(source, offset);

                Pointer targetPointer = pointer(target);

                if (targetCount == 2 || ArrayRegionEqualsNode.regionEquals(cmpSourcePointer, targetPointer, targetCount, JavaKind.Char, JavaKind.Byte)) {

                    return offset;

                }

                offset++;

            }

            return -1;

        }

    }

    /**

     * Intrinsic for {@code java.lang.StringUTF16.compress([CI[BII)I}.

     *

     * <pre>

     * @HotSpotIntrinsicCandidate

     * public static int compress(char[] src, int src_indx, byte[] dst, int dst_indx, int len)

     * </pre>

     */

    @MethodSubstitution

    public static int compress(char[] src, int srcIndex, byte[] dest, int destIndex, int len) {

        checkLimits(src.length, srcIndex, dest.length, destIndex, len);

        Pointer srcPointer = Word.objectToTrackedPointer(src).add(charArrayBaseOffset(INJECTED)).add(srcIndex * charArrayIndexScale(INJECTED));

        Pointer destPointer = Word.objectToTrackedPointer(dest).add(byteArrayBaseOffset(INJECTED)).add(destIndex * byteArrayIndexScale(INJECTED));

        return AMD64StringUTF16CompressNode.compress(srcPointer, destPointer, len, JavaKind.Char);

    }

    /**

     * Intrinsic for {@code }java.lang.StringUTF16.compress([BI[BII)I}.

     *

     * <pre>

     * @HotSpotIntrinsicCandidate

     * public static int compress(byte[] src, int src_indx, byte[] dst, int dst_indx, int len)

     * </pre>

     * <p>

     * In this variant {@code dest} refers to a byte array containing 2 byte per char so

     * {@code srcIndex} and {@code len} are in terms of char elements and have to be scaled by 2

     * when referring to {@code src}.

     */

    @MethodSubstitution

    public static int compress(byte[] src, int srcIndex, byte[] dest, int destIndex, int len) {

        checkLimits(src.length >> 1, srcIndex, dest.length, destIndex, len);

        Pointer srcPointer = Word.objectToTrackedPointer(src).add(byteArrayBaseOffset(INJECTED)).add(srcIndex * 2 * byteArrayIndexScale(INJECTED));

        Pointer destPointer = Word.objectToTrackedPointer(dest).add(byteArrayBaseOffset(INJECTED)).add(destIndex * byteArrayIndexScale(INJECTED));

        return AMD64StringUTF16CompressNode.compress(srcPointer, destPointer, len, JavaKind.Byte);

    }

    private static void checkLimits(int srcLen, int srcIndex, int destLen, int destIndex, int len) {

        if (len < 0 || srcIndex < 0 || (srcIndex + len > srcLen) || destIndex < 0 || (destIndex + len > destLen)) {

            DeoptimizeNode.deopt(DeoptimizationAction.None, DeoptimizationReason.BoundsCheckException);

        }

    }

}