/***************************************************************************
Copyright (c) 2014, The OpenBLAS Project
All rights reserved.
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modification, are permitted provided that the following conditions are
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2. Redistributions in binary form must reproduce the above copyright
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its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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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) || defined (COOPERLAKE) || defined (SAPPHIRERAPIDS)
#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,
				    (int (*)(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;
}
