OpenBLAS/kernel/power/sgemv_n.c

/***************************************************************************
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#if !defined(__VEC__) || !defined(__ALTIVEC__)
#include "../arm/gemv_n.c"

#else

#include <altivec.h>

#include "common.h"
#define NBMAX 4096

static void sgemv_kernel_4x8(BLASLONG n, FLOAT **ap, FLOAT *xo, FLOAT *y,
                             BLASLONG lda4, FLOAT *alpha) {
    BLASLONG i;
    FLOAT *a0, *a1, *a2, *a3, *b0, *b1, *b2, *b3;
    FLOAT x0, x1, x2, x3, x4, x5, x6, x7;
    a0 = ap[0];
    a1 = ap[1];
    a2 = ap[2];
    a3 = ap[3];
    b0 = a0 + lda4;
    b1 = a1 + lda4;
    b2 = a2 + lda4;
    b3 = a3 + lda4;
    x0 = xo[0] * (*alpha);
    x1 = xo[1] * (*alpha);
    x2 = xo[2] * (*alpha);
    x3 = xo[3] * (*alpha);
    x4 = xo[4] * (*alpha);
    x5 = xo[5] * (*alpha);
    x6 = xo[6] * (*alpha);
    x7 = xo[7] * (*alpha);

    __vector float v_x0 = {x0, x0, x0, x0};
    __vector float v_x1 = {x1, x1, x1, x1};
    __vector float v_x2 = {x2, x2, x2, x2};
    __vector float v_x3 = {x3, x3, x3, x3};
    __vector float v_x4 = {x4, x4, x4, x4};
    __vector float v_x5 = {x5, x5, x5, x5};
    __vector float v_x6 = {x6, x6, x6, x6};
    __vector float v_x7 = {x7, x7, x7, x7};

    for (i = 0; i < n; i += 4) {
        __vector float vy = vec_vsx_ld(0, &y[i]);
        __vector float va0 = vec_vsx_ld(0, &a0[i]);
        __vector float va1 = vec_vsx_ld(0, &a1[i]);
        __vector float va2 = vec_vsx_ld(0, &a2[i]);
        __vector float va3 = vec_vsx_ld(0, &a3[i]);
        __vector float vb0 = vec_vsx_ld(0, &b0[i]);
        __vector float vb1 = vec_vsx_ld(0, &b1[i]);
        __vector float vb2 = vec_vsx_ld(0, &b2[i]);
        __vector float vb3 = vec_vsx_ld(0, &b3[i]);
        vy += v_x0 * va0 + v_x1 * va1 + v_x2 * va2 + v_x3 * va3;
        vy += v_x4 * vb0 + v_x5 * vb1 + v_x6 * vb2 + v_x7 * vb3;
        vec_vsx_st(vy, 0, &y[i]);
    }
}

static void sgemv_kernel_4x4(BLASLONG n, FLOAT **ap, FLOAT *xo, FLOAT *y,
                             FLOAT *alpha) {
    BLASLONG i;
    FLOAT x0, x1, x2, x3;
    FLOAT *a0, *a1, *a2, *a3;
    a0 = ap[0];
    a1 = ap[1];
    a2 = ap[2];
    a3 = ap[3];
    x0 = xo[0] * (*alpha);
    x1 = xo[1] * (*alpha);
    x2 = xo[2] * (*alpha);
    x3 = xo[3] * (*alpha);
    __vector float v_x0 = {x0, x0, x0, x0};
    __vector float v_x1 = {x1, x1, x1, x1};
    __vector float v_x2 = {x2, x2, x2, x2};
    __vector float v_x3 = {x3, x3, x3, x3};

    for (i = 0; i < n; i += 4) {
        __vector float vy = vec_vsx_ld(0, &y[i]);
        __vector float va0 = vec_vsx_ld(0, &a0[i]);
        __vector float va1 = vec_vsx_ld(0, &a1[i]);
        __vector float va2 = vec_vsx_ld(0, &a2[i]);
        __vector float va3 = vec_vsx_ld(0, &a3[i]);
        vy += v_x0 * va0 + v_x1 * va1 + v_x2 * va2 + v_x3 * va3;
        vec_vsx_st(vy, 0, &y[i]);
    }
}

static void sgemv_kernel_4x2(BLASLONG n, FLOAT **ap, FLOAT *x, FLOAT *y,
                             FLOAT *alpha) {
    BLASLONG i;
    FLOAT x0, x1;
    FLOAT *a0, *a1;
    a0 = ap[0];
    a1 = ap[1];
    x0 = x[0] * (*alpha);
    x1 = x[1] * (*alpha);
    __vector float v_x0 = {x0, x0, x0, x0};
    __vector float v_x1 = {x1, x1, x1, x1};

    for (i = 0; i < n; i += 4) {
        __vector float vy = vec_vsx_ld(0, &y[i]);
        __vector float va0 = vec_vsx_ld(0, &a0[i]);
        __vector float va1 = vec_vsx_ld(0, &a1[i]);
        vy += v_x0 * va0 + v_x1 * va1;
        vec_vsx_st(vy, 0, &y[i]);
    }
}

static void sgemv_kernel_4x1(BLASLONG n, FLOAT *ap, FLOAT *x, FLOAT *y,
                             FLOAT *alpha) {
    BLASLONG i;
    FLOAT x0 = x[0] * (*alpha);
    __vector float v_x0 = {x0, x0, x0, x0};

    for (i = 0; i < n; i += 4) {
        __vector float vy = vec_vsx_ld(0, &y[i]);
        __vector float va0 = vec_vsx_ld(0, &ap[i]);
        vy += v_x0 * va0;
        vec_vsx_st(vy, 0, &y[i]);
    }
}

static void add_y(BLASLONG n, FLOAT *src, FLOAT *dest, BLASLONG inc_dest) {
    BLASLONG i;

    for (i = 0; i < n; i++) {
        *dest += *src;
        src++;
        dest += inc_dest;
    }
    return;
}

int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT alpha, FLOAT *a,
          BLASLONG lda, FLOAT *x, BLASLONG inc_x, FLOAT *y, BLASLONG inc_y,
          FLOAT *buffer) {
    BLASLONG i, n1, m1, m2, m3, n2, lda4, lda8;
    FLOAT *a_ptr, *x_ptr, *y_ptr, *ap[4];

    lda4 = lda << 2;
    lda8 = lda << 3;
    FLOAT xbuffer[8] __attribute__((aligned(16)));
    FLOAT *ybuffer = buffer;

    if (m < 1) return (0);
    if (n < 1) return (0);

    if (inc_x == 1) {
        n1 = n >> 3;
        n2 = n & 7;
    } else {
        n1 = n >> 2;
        n2 = n & 3;
    }

    m3 = m & 3;
    m1 = m & -4;
    m2 = (m & (NBMAX - 1)) - m3;
    y_ptr = y;
    BLASLONG NB = NBMAX;

    while (NB == NBMAX) {
        m1 -= NB;
        if (m1 < 0) {
            if (m2 == 0) break;
            NB = m2;
        }

        a_ptr = a;
        x_ptr = x;

        ap[0] = a_ptr;
        ap[1] = a_ptr + lda;
        ap[2] = ap[1] + lda;
        ap[3] = ap[2] + lda;

        if (inc_y != 1)
            memset(ybuffer, 0, NB * 4);
        else
            ybuffer = y_ptr;

        if (inc_x == 1) {
            for (i = 0; i < n1; i++) {
                sgemv_kernel_4x8(NB, ap, x_ptr, ybuffer, lda4, &alpha);
                ap[0] += lda8;
                ap[1] += lda8;
                ap[2] += lda8;
                ap[3] += lda8;
                a_ptr += lda8;
                x_ptr += 8;
            }
            if (n2 & 4) {
                sgemv_kernel_4x4(NB, ap, x_ptr, ybuffer, &alpha);
                ap[0] += lda4;
                ap[1] += lda4;
                ap[2] += lda4;
                ap[3] += lda4;
                a_ptr += lda4;
                x_ptr += 4;
            }

            if (n2 & 2) {
                sgemv_kernel_4x2(NB, ap, x_ptr, ybuffer, &alpha);
                a_ptr += lda * 2;
                x_ptr += 2;
            }

            if (n2 & 1) {
                sgemv_kernel_4x1(NB, a_ptr, x_ptr, ybuffer, &alpha);
                a_ptr += lda;
                x_ptr += 1;
            }

        } else {
            for (i = 0; i < n1; i++) {
                xbuffer[0] = x_ptr[0];
                x_ptr += inc_x;
                xbuffer[1] = x_ptr[0];
                x_ptr += inc_x;
                xbuffer[2] = x_ptr[0];
                x_ptr += inc_x;
                xbuffer[3] = x_ptr[0];
                x_ptr += inc_x;
                sgemv_kernel_4x4(NB, ap, xbuffer, ybuffer, &alpha);
                ap[0] += lda4;
                ap[1] += lda4;
                ap[2] += lda4;
                ap[3] += lda4;
                a_ptr += lda4;
            }

            for (i = 0; i < n2; i++) {
                xbuffer[0] = x_ptr[0];
                x_ptr += inc_x;
                sgemv_kernel_4x1(NB, a_ptr, xbuffer, ybuffer, &alpha);
                a_ptr += lda;
            }
        }

        a += NB;
        if (inc_y != 1) {
            add_y(NB, ybuffer, y_ptr, inc_y);
            y_ptr += NB * inc_y;
        } else
            y_ptr += NB;
    }

    if (m3 == 0) return (0);

    if (m3 == 3) {
        a_ptr = a;
        x_ptr = x;
        FLOAT temp0 = 0.0;
        FLOAT temp1 = 0.0;
        FLOAT temp2 = 0.0;
        if (lda == 3 && inc_x == 1) {
            for (i = 0; i < (n & -4); i += 4) {
                temp0 += a_ptr[0] * x_ptr[0] + a_ptr[3] * x_ptr[1];
                temp1 += a_ptr[1] * x_ptr[0] + a_ptr[4] * x_ptr[1];
                temp2 += a_ptr[2] * x_ptr[0] + a_ptr[5] * x_ptr[1];

                temp0 += a_ptr[6] * x_ptr[2] + a_ptr[9] * x_ptr[3];
                temp1 += a_ptr[7] * x_ptr[2] + a_ptr[10] * x_ptr[3];
                temp2 += a_ptr[8] * x_ptr[2] + a_ptr[11] * x_ptr[3];

                a_ptr += 12;
                x_ptr += 4;
            }

            for (; i < n; i++) {
                temp0 += a_ptr[0] * x_ptr[0];
                temp1 += a_ptr[1] * x_ptr[0];
                temp2 += a_ptr[2] * x_ptr[0];
                a_ptr += 3;
                x_ptr++;
            }

        } else {
            for (i = 0; i < n; i++) {
                temp0 += a_ptr[0] * x_ptr[0];
                temp1 += a_ptr[1] * x_ptr[0];
                temp2 += a_ptr[2] * x_ptr[0];
                a_ptr += lda;
                x_ptr += inc_x;
            }
        }
        y_ptr[0] += alpha * temp0;
        y_ptr += inc_y;
        y_ptr[0] += alpha * temp1;
        y_ptr += inc_y;
        y_ptr[0] += alpha * temp2;
        return (0);
    }

    if (m3 == 2) {
        a_ptr = a;
        x_ptr = x;
        FLOAT temp0 = 0.0;
        FLOAT temp1 = 0.0;
        if (lda == 2 && inc_x == 1) {
            for (i = 0; i < (n & -4); i += 4) {
                temp0 += a_ptr[0] * x_ptr[0] + a_ptr[2] * x_ptr[1];
                temp1 += a_ptr[1] * x_ptr[0] + a_ptr[3] * x_ptr[1];
                temp0 += a_ptr[4] * x_ptr[2] + a_ptr[6] * x_ptr[3];
                temp1 += a_ptr[5] * x_ptr[2] + a_ptr[7] * x_ptr[3];
                a_ptr += 8;
                x_ptr += 4;
            }

            for (; i < n; i++) {
                temp0 += a_ptr[0] * x_ptr[0];
                temp1 += a_ptr[1] * x_ptr[0];
                a_ptr += 2;
                x_ptr++;
            }

        } else {
            for (i = 0; i < n; i++) {
                temp0 += a_ptr[0] * x_ptr[0];
                temp1 += a_ptr[1] * x_ptr[0];
                a_ptr += lda;
                x_ptr += inc_x;
            }
        }
        y_ptr[0] += alpha * temp0;
        y_ptr += inc_y;
        y_ptr[0] += alpha * temp1;
        return (0);
    }

    if (m3 == 1) {
        a_ptr = a;
        x_ptr = x;
        FLOAT temp = 0.0;
        if (lda == 1 && inc_x == 1) {
            for (i = 0; i < (n & -4); i += 4) {
                temp += a_ptr[i] * x_ptr[i] + a_ptr[i + 1] * x_ptr[i + 1] +
                        a_ptr[i + 2] * x_ptr[i + 2] +
                        a_ptr[i + 3] * x_ptr[i + 3];
            }

            for (; i < n; i++) {
                temp += a_ptr[i] * x_ptr[i];
            }

        } else {
            for (i = 0; i < n; i++) {
                temp += a_ptr[0] * x_ptr[0];
                a_ptr += lda;
                x_ptr += inc_x;
            }
        }
        y_ptr[0] += alpha * temp;
        return (0);
    }

    return (0);
}

#endif