OpenBLAS/kernel/arm64/ddot_thunderx.c

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#include "common.h"

#include <arm_neon.h>

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

FLOAT CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x, FLOAT *y, BLASLONG inc_y)
{
	BLASLONG i=0;
	BLASLONG ix=0,iy=0;

	FLOAT  dot = 0.0 ;

	if ( n < 0 )  return(dot);

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

                float64x2_t vdot0 = {0.0, 0.0};
                float64x2_t vdot1 = {0.0, 0.0};
                float64x2_t vdot2 = {0.0, 0.0};
                float64x2_t vdot3 = {0.0, 0.0};
                float64x2_t *vx = (float64x2_t*)x;
                float64x2_t *vy = (float64x2_t*)y;
#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));

		int n1 = n&-8;

		while(i < n1)
		{
#if 0
			vdot0 = vfmaq_f64 (vdot0,
					   vy[0],
					   vx[0]);
			vdot1 = vfmaq_f64 (vdot1,
					   vy[1],
					   vx[1]);
			vdot2 = vfmaq_f64 (vdot2,
					   vy[2],
					   vx[2]);
			vdot3 = vfmaq_f64 (vdot3,
					   vy[3],
					   vx[3]);
#else
			vdot0 = vy[0] * vx[0] + vdot0;
			vdot1 = vy[1] * vx[1] + vdot1;
			vdot2 = vy[2] * vx[2] + vdot2;
			vdot3 = vy[3] * vx[3] + vdot3;
#endif
			vy += 4;
			vx += 4;
			i += 8;
			prefetch(vx + 3*128/sizeof(*x));
			prefetch(vy + 3*128/sizeof(*y));

		}
		dot = vaddvq_f64 (vdot0 + vdot1);
		dot += vaddvq_f64 (vdot2 + vdot3);
		i = n1;

		while(i < n)
		{
			dot += y[i] * x[i] ;
			i++ ;

		}
		return(dot);


	}

	while(i < n)
	{
		dot += y[iy] * x[ix] ;
		ix  += inc_x ;
		iy  += inc_y ;
		i++ ;

	}
	return(dot);

}