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/*
 * @test
 * @bug 8330819
 * @summary Case where VPointer finds an "adr" CastX2P, which contains a CastLL,
 *          that has a ctrl after the pre-loop. This value cannot be used in the
 *          pre-loop limit for main-loop adjustment.
 * @modules java.base/jdk.internal.misc
 * @modules java.base/jdk.internal.util
 * @run main/othervm -Xbatch compiler.loopopts.superword.TestMemorySegmentMainLoopAlignment
 */

package compiler.loopopts.superword;

import java.lang.foreign.*;
import jdk.internal.misc.Unsafe;
import jdk.internal.util.Preconditions;

public class TestMemorySegmentMainLoopAlignment {
    static final ValueLayout.OfInt ELEMENT_LAYOUT = ValueLayout.JAVA_INT.withByteAlignment(1);
    static final Unsafe UNSAFE = Unsafe.getUnsafe();
    static long RANGE = 6400;

    // Type definition for the lambda
    interface MSOp {
        int apply(MemorySegment memory, long offset, int i);
    }

    // Type definition for the lambda
    interface MemoryUnsafeOp {
        int apply(long base, long offset, int i);
    }

    public static void main(String[] args) {
        // Allocate some raw memory:
        MemorySegment ms = Arena.ofAuto().allocate(6400, Integer.SIZE);
        for (int i = 0; i < 10_000; i++) {
            test1(ms, 0, TestMemorySegmentMainLoopAlignment::memorySegmentGet);
        }
        // Allocate some raw memory:
        long base = UNSAFE.allocateMemory(6400);
        for (int i = 0; i < 10_000; i++) {
            test2(base, 0, TestMemorySegmentMainLoopAlignment::memoryUnsafeGet);
        }
    }

    // Somehow, it is necessary to pass this as a lambda
    // the checkIndex inside the "get" method produces the CastLL, which eventually pins the index
    // between the pre and main loop.
    static int memorySegmentGet(MemorySegment ms, long o, int i) {
        return ms.get(ELEMENT_LAYOUT, o + i * 4L);
    }

    static int test1(MemorySegment a, long offset, MSOp f) {
        // Constant size array size allows a known range for the array access/loop iv i.
        int size = 16;
        int[] res = new int[size];
        int sum = 0;
        for (int i = 0; i < size; i++) {
            // With inlining, this eventually becomes:
            // sum += LoadI(MemorySegment / unsafe) + LoadI(array)
            // and we attempt vectorization.
            sum += f.apply(a, offset, i) + res[i];
        }
        return sum;
    }

    // Somehow, it is necessary to pass this as a lambda
    static int memoryUnsafeGet(long base, long o, int i) {
        long index = o + i * 4L;
        // checkIndex -> CastLL: index >= 0.
        // Together with the info about i (known range for phi), this CastLL floats up to
        // the offset. Then we get adr = CastX2P(base + CastLL(offset)), where the CastLL
        // is pinned between the pre and main loop.
        Preconditions.checkIndex(index, RANGE, null);
        return UNSAFE.getInt(base + index);
    }

    static int test2(long base, long offset, MemoryUnsafeOp f) {
        // Constant size array size allows a known range for the array access/loop iv i.
        int size = 16;
        int[] res = new int[size];
        int sum = 0;
        for (int i = 0; i < size; i++) {
            // With inlining, this eventually becomes:
            // sum += LoadI(unsafe) + LoadI(array)
            // and we attempt vectorization.
            sum += f.apply(base, offset, i) + res[i];
        }
        return sum;
    }
}