OpenBLAS/kernel/arm64/daxpy-thunderx.c

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#include "common.h"
#include <arm_neon.h>

#define prefetch(a) __asm__("prfm PLDL1STRM, [%0]"::"r"(a):"memory");
//#define prefetch(a)

static void daxpy_kernel_8(BLASLONG n, FLOAT *x, FLOAT *y, FLOAT *alpha)
{
	BLASLONG register i = 0;
	double a = *alpha;

#if 0
        prefetch(x + 128/sizeof(*x));
        prefetch(y + 128/sizeof(*y));
#endif
        prefetch(x + 2*128/sizeof(*x));
        prefetch(y + 2*128/sizeof(*y));
        prefetch(x + 3*128/sizeof(*x));
        prefetch(y + 3*128/sizeof(*y));
        prefetch(x + 4*128/sizeof(*x));
        prefetch(y + 4*128/sizeof(*y));

	while(i < n)
        {
	      double y0, y1, y2, y3;
	      double y4, y5, y6, y7;
	      double *xx;
	      double *yy;
              y0 = a * x[0] + y[0];
              y1 = a * x[1] + y[1];
              y2 = a * x[2] + y[2];
              y3 = a * x[3] + y[3];
              y4 = a * x[4] + y[4];
              y5 = a * x[5] + y[5];
              y6 = a * x[6] + y[6];
              y7 = a * x[7] + y[7];
	      asm("":"+w"(y0),"+w"(y1),"+w"(y2),"+w"(y3),"+w"(y4),"+w"(y5),"+w"(y6),"+w"(y7));
	      y[0] = y0;
	      y[1] = y1;
	      y[2] = y2;
	      y[3] = y3;
	      y[4] = y4;
	      y[5] = y5;
	      y[6] = y6;
	      y[7] = y7;

              xx = (x + 4*128/sizeof(*x));
              yy = (y + 4*128/sizeof(*y));
	      asm("":"+r"(yy)::"memory");
	      prefetch(xx);
	      prefetch(yy);

	      y += 8;
	      x += 8;
              i += 8 ;
	}

}


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;
	BLASLONG ix=0,iy=0;

	if ( n <= 0 )  return(0);

	if ( (inc_x == 1) && (inc_y == 1) )
	{

		BLASLONG n1 = n & -32;

		if ( n1 )
			daxpy_kernel_8(n1, x, y , &da );

		i = n1;
		while(i < n)
		{

			y[i] += da * x[i] ;
			i++ ;

		}
		return(0);


	}

	BLASLONG n1 = n & -4;

	while(i < n1)
	{

		FLOAT m1      = da * x[ix] ;
		FLOAT m2      = da * x[ix+inc_x] ;
		FLOAT m3      = da * x[ix+2*inc_x] ;
		FLOAT m4      = da * x[ix+3*inc_x] ;

		y[iy]         += m1 ;
		y[iy+inc_y]   += m2 ;
		y[iy+2*inc_y] += m3 ;
		y[iy+3*inc_y] += m4 ;

		ix  += inc_x*4 ;
		iy  += inc_y*4 ;
		i+=4 ;

	}

	while(i < n)
	{

		y[iy] += da * x[ix] ;
		ix  += inc_x ;
		iy  += inc_y ;
		i++ ;

	}
	return(0);

}