OpenBLAS/kernel/x86_64/sscal.c

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#include "common.h"

#if defined(HASWELL) || defined(ZEN)
#include "sscal_microk_haswell-2.c"
#elif  defined (SKYLAKEX) || defined (COOPERLAKE) || defined (SAPPHIRERAPIDS)
#include "sscal_microk_skylakex-2.c"
#endif


#if !defined(HAVE_KERNEL_16)

static void sscal_kernel_16( BLASLONG n, FLOAT *da , FLOAT *x )
{

    BLASLONG i;
    FLOAT alpha = *da;

    for( i=0; i<n; i+=8 )
    {
        x[0] *= alpha;
        x[1] *= alpha;
        x[2] *= alpha;
        x[3] *= alpha;
        x[4] *= alpha;
        x[5] *= alpha;
        x[6] *= alpha;
        x[7] *= alpha;
        x+=8;
    }

}


static void sscal_kernel_16_zero( BLASLONG n, FLOAT *alpha , FLOAT *x )
{

    BLASLONG i;
    for( i=0; i<n; i+=8 )
    {
        x[0] = 0.0;
        x[1] = 0.0;
        x[2] = 0.0;
        x[3] = 0.0;
        x[4] = 0.0;
        x[5] = 0.0;
        x[6] = 0.0;
        x[7] = 0.0;
        x+=8;
    }

}

#endif


static void sscal_kernel_inc_8(BLASLONG n, FLOAT *alpha, FLOAT *x, BLASLONG inc_x)  __attribute__ ((noinline));

static void sscal_kernel_inc_8(BLASLONG n, FLOAT *alpha, FLOAT *x, BLASLONG inc_x)
{

    BLASLONG i;
    BLASLONG inc_x2 = 2 * inc_x;
    BLASLONG inc_x3 = inc_x2 + inc_x;
    FLOAT t0,t1,t2,t3;
    FLOAT da = alpha[0];

    for ( i=0; i<n; i+=4 )
    {
        t0 = da * x[0];
        t1 = da * x[inc_x];
        t2 = da * x[inc_x2];
        t3 = da * x[inc_x3];

        x[0]        = t0;
        x[inc_x]    = t1;
        x[inc_x2]   = t2;
        x[inc_x3]   = t3;

        x+=4*inc_x;

    }


}

int CNAME(BLASLONG n, BLASLONG dummy0, BLASLONG dummy1, FLOAT da, FLOAT *x, BLASLONG inc_x, FLOAT *y, BLASLONG inc_y, FLOAT *dummy, BLASLONG dummy2)
{
    BLASLONG i = 0, j = 0;

    // Resolved issue 4728 when the caller is sscal
    if (dummy2 == 1 && da == 0.0)
    {
        if ( inc_x != 1 )
        {
            BLASLONG n1 = n & -8;
            if ( n1 > 0 )
            {
                sscal_kernel_inc_8(n1, &da, x, inc_x);
                i = n1 * inc_x;
                j = n1;
            }
            while(j < n)
            {
                x[i] *= da;
                i += inc_x ;
                j++;
            }
        }
        else
        {
            BLASLONG n1 = n & -16;
            if ( n1 > 0)
                sscal_kernel_16(n1 , &da , x);
            for ( i = n1 ; i < n; i++ )
                x[i] *= da;
        }
    }
    else
    {
        if ( inc_x != 1 )
        {
            if( da == 0.0)
            {
                BLASLONG n1 = n & -2;
                while(j < n1)
                {
                    x[i] = 0.0;
                    x[i+inc_x] = 0.0;
                    i += 2 * inc_x ;
                    j += 2;
                }
                while(j < n)
                {
                    x[i] = 0.0;
                    i += inc_x ;
                    j++;
                }
            }
            else
            {
                BLASLONG n1 = n & -8;
                if ( n1 > 0 )
                {
                    sscal_kernel_inc_8(n1, &da, x, inc_x);
                    i = n1 * inc_x;
                    j = n1;
                }
                while(j < n)
                {
                    x[i] *= da;
                    i += inc_x ;
                    j++;
                }
            }
        }
        else
        {
            if ( da == 0.0 )
            {
                BLASLONG n1 = n & -16;
                if ( n1 > 0)
                   sscal_kernel_16_zero(n1, &da, x);
                for ( i = n1 ; i < n; i++ )
                    x[i] = 0.0;
            }
            else
            {
                BLASLONG n1 = n & -16;
                if ( n1 > 0)
                    sscal_kernel_16(n1 , &da , x);
                for ( i = n1 ; i < n; i++ )
                    x[i] *= da;
            }
        }
    }
}