DOT.java

/*
MIT License

Copyright (c) 2019 Gleethos

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of this software and associated documentation files (the "Software"), to deal
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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*/
package neureka.backend.main.operations.linear.internal.blas;

/**
 * The ?dot routines perform a vector-vector reduction operation defined as Equation where xi and yi are
 * elements of vectors x and y.
 *
 */
public final class DOT
{
    public static double invoke(final double[] array1, final int offset1, final double[] array2, final int offset2, final int first, final int limit) {
        return DOT.unrolled04(array1, offset1, array2, offset2, first, limit);
    }

    public static float invoke(final float[] array1, final int offset1, final float[] array2, final int offset2, final int first, final int limit) {
        return DOT.unrolled04(array1, offset1, array2, offset2, first, limit);
    }

    public static long invoke(final long[] array1, final int offset1, final long[] array2, final int offset2, final int first, final int limit) {
        return DOT.unrolled04(array1, offset1, array2, offset2, first, limit);
    }

    public static int invoke(final int[] array1, final int offset1, final int[] array2, final int offset2, final int first, final int limit) {
        return DOT.unrolled04(array1, offset1, array2, offset2, first, limit);
    }

    static long unrolled04(final long[] array1, final int offset1, final long[] array2, final int offset2, final int first, final int limit) {

        int remainder = (limit - first) % 4;

        long sum0 = 0L;
        long sum1 = 0L;
        long sum2 = 0L;
        long sum3 = 0L;

        int shift10 = offset1 + 0;
        int shift11 = offset1 + 1;
        int shift12 = offset1 + 2;
        int shift13 = offset1 + 3;

        int shift20 = offset2 + 0;
        int shift21 = offset2 + 1;
        int shift22 = offset2 + 2;
        int shift23 = offset2 + 3;

        int i = first;
        for (int lim = limit - remainder; i < lim; i += 4) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
            sum1 += array1[shift11 + i] * array2[shift21 + i];
            sum2 += array1[shift12 + i] * array2[shift22 + i];
            sum3 += array1[shift13 + i] * array2[shift23 + i];
        }
        for (; i < limit; i++) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
        }

        return sum0 + sum1 + sum2 + sum3;
    }

    static int unrolled04(final int[] array1, final int offset1, final int[] array2, final int offset2, final int first, final int limit) {

        int remainder = (limit - first) % 4;

        int sum0 = 0;
        int sum1 = 0;
        int sum2 = 0;
        int sum3 = 0;

        int shift10 = offset1 + 0;
        int shift11 = offset1 + 1;
        int shift12 = offset1 + 2;
        int shift13 = offset1 + 3;

        int shift20 = offset2 + 0;
        int shift21 = offset2 + 1;
        int shift22 = offset2 + 2;
        int shift23 = offset2 + 3;

        int i = first;
        for (int lim = limit - remainder; i < lim; i += 4) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
            sum1 += array1[shift11 + i] * array2[shift21 + i];
            sum2 += array1[shift12 + i] * array2[shift22 + i];
            sum3 += array1[shift13 + i] * array2[shift23 + i];
        }
        for (; i < limit; i++) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
        }

        return sum0 + sum1 + sum2 + sum3;
    }

    static double unrolled04(final double[] array1, final int offset1, final double[] array2, final int offset2, final int first, final int limit) {

        int remainder = (limit - first) % 4;

        double sum0 = 0F;
        double sum1 = 0F;
        double sum2 = 0F;
        double sum3 = 0F;

        int shift10 = offset1 + 0;
        int shift11 = offset1 + 1;
        int shift12 = offset1 + 2;
        int shift13 = offset1 + 3;

        int shift20 = offset2 + 0;
        int shift21 = offset2 + 1;
        int shift22 = offset2 + 2;
        int shift23 = offset2 + 3;

        int i = first;
        for (int lim = limit - remainder; i < lim; i += 4) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
            sum1 += array1[shift11 + i] * array2[shift21 + i];
            sum2 += array1[shift12 + i] * array2[shift22 + i];
            sum3 += array1[shift13 + i] * array2[shift23 + i];
        }
        for (; i < limit; i++) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
        }

        return sum0 + sum1 + sum2 + sum3;
    }

    static float unrolled04(final float[] array1, final int offset1, final float[] array2, final int offset2, final int first, final int limit) {

        int remainder = (limit - first) % 4;

        float sum0 = 0F;
        float sum1 = 0F;
        float sum2 = 0F;
        float sum3 = 0F;

        int shift10 = offset1 + 0;
        int shift11 = offset1 + 1;
        int shift12 = offset1 + 2;
        int shift13 = offset1 + 3;

        int shift20 = offset2 + 0;
        int shift21 = offset2 + 1;
        int shift22 = offset2 + 2;
        int shift23 = offset2 + 3;

        int i = first;
        for (int lim = limit - remainder; i < lim; i += 4) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
            sum1 += array1[shift11 + i] * array2[shift21 + i];
            sum2 += array1[shift12 + i] * array2[shift22 + i];
            sum3 += array1[shift13 + i] * array2[shift23 + i];
        }
        for (; i < limit; i++) {
            sum0 += array1[shift10 + i] * array2[shift20 + i];
        }

        return sum0 + sum1 + sum2 + sum3;
    }

}