OpenBLAS/kernel/x86_64/ddot.c

/***************************************************************************
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#include "common.h"


#if defined(BULLDOZER)
#include "ddot_microk_bulldozer-2.c"
#elif defined(STEAMROLLER)  || defined(EXCAVATOR)
#include "ddot_microk_steamroller-2.c"
#elif defined(PILEDRIVER)
#include "ddot_microk_piledriver-2.c"
#elif defined(NEHALEM)
#include "ddot_microk_nehalem-2.c"
#elif defined(HASWELL) || defined(ZEN)
#include "ddot_microk_haswell-2.c"
#elif defined (SKYLAKEX)
#include "ddot_microk_skylakex-2.c"
#elif defined(SANDYBRIDGE)
#include "ddot_microk_sandy-2.c"
#endif

#if !defined(DSDOT)
#define RETURN_TYPE     FLOAT
#else
#define RETURN_TYPE     double
#endif


#ifndef HAVE_KERNEL_8

static void ddot_kernel_8(BLASLONG n, FLOAT *x, FLOAT *y, FLOAT *d)
{
	BLASLONG register i = 0;
	FLOAT dot = 0.0;

	while(i < n)
        {
              dot += y[i]  * x[i]
                  + y[i+1] * x[i+1]
                  + y[i+2] * x[i+2]
                  + y[i+3] * x[i+3]
                  + y[i+4] * x[i+4]
                  + y[i+5] * x[i+5]
                  + y[i+6] * x[i+6]
                  + y[i+7] * x[i+7] ;

              i+=8 ;

       }
       *d += dot;

}

#endif

static FLOAT dot_compute(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) )
	{

		BLASLONG n1 = n & -16;

		if ( n1 )
			ddot_kernel_8(n1, x, y , &dot );

		i = n1;
		while(i < n)
		{

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

		}
		return(dot);


	}

	FLOAT temp1 = 0.0;
	FLOAT temp2 = 0.0;

        BLASLONG n1 = n & -4;

	while(i < n1)
	{

		FLOAT m1 = y[iy]       * x[ix] ;
		FLOAT m2 = y[iy+inc_y] * x[ix+inc_x] ;

		FLOAT m3 = y[iy+2*inc_y] * x[ix+2*inc_x] ;
		FLOAT m4 = y[iy+3*inc_y] * x[ix+3*inc_x] ;

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

		temp1 += m1+m3;
		temp2 += m2+m4;

		i+=4 ;

	}

	while(i < n)
	{

		temp1 += y[iy] * x[ix] ;
		ix  += inc_x ;
		iy  += inc_y ;
		i++ ;

	}
	dot = temp1 + temp2;
	return(dot);

}

#if defined(SMP)
static int dot_thread_function(BLASLONG n, BLASLONG dummy0,
        BLASLONG dummy1, FLOAT dummy2, FLOAT *x, BLASLONG inc_x, FLOAT *y,
        BLASLONG inc_y, RETURN_TYPE *result, BLASLONG dummy3)
{
        *(RETURN_TYPE *)result = dot_compute(n, x, inc_x, y, inc_y);

        return 0;
}

extern int blas_level1_thread_with_return_value(int mode, BLASLONG m, BLASLONG n,
        BLASLONG k, void *alpha, void *a, BLASLONG lda, void *b, BLASLONG ldb,
        void *c, BLASLONG ldc, int (*function)(), int nthreads);
#endif

FLOAT CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x, FLOAT *y, BLASLONG inc_y)
{
#if defined(SMP)
	int nthreads;
	FLOAT dummy_alpha;
#endif
	FLOAT dot = 0.0;

#if defined(SMP)
	if (inc_x == 0 || inc_y == 0 || n <= 10000)
		nthreads = 1;
	else
		nthreads = num_cpu_avail(1);

	if (nthreads == 1) {
		dot = dot_compute(n, x, inc_x, y, inc_y);
	} else {
		int mode, i;
		char result[MAX_CPU_NUMBER * sizeof(double) * 2];
		RETURN_TYPE *ptr;

#if !defined(DOUBLE)
		mode = BLAS_SINGLE  | BLAS_REAL;
#else
		mode = BLAS_DOUBLE  | BLAS_REAL;
#endif
		blas_level1_thread_with_return_value(mode, n, 0, 0, &dummy_alpha,
				   x, inc_x, y, inc_y, result, 0,
				   ( void *)dot_thread_function, nthreads);

		ptr = (RETURN_TYPE *)result;
		for (i = 0; i < nthreads; i++) {
			dot = dot + (*ptr);
			ptr = (RETURN_TYPE *)(((char *)ptr) + sizeof(double) * 2);
		}
	}
#else
	dot = dot_compute(n, x, inc_x, y, inc_y);
#endif

	return dot;
}