OpenBLAS/kernel/x86_64/dgemv_n_4.c

/***************************************************************************
Copyright (c) 2014, The OpenBLAS Project
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its contributors may be used to endorse or promote products
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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*****************************************************************************/


#include "common.h"


#if defined(NEHALEM)
#include "dgemv_n_microk_nehalem-4.c"
#elif defined(HASWELL) || defined(STEAMROLLER) || defined(EXCAVATOR)
#include "dgemv_n_microk_haswell-4.c"
#endif


#define NBMAX 2048
#ifndef HAVE_KERNEL_4x4

static void dgemv_kernel_4x4(BLASLONG n, FLOAT **ap, FLOAT *xo, FLOAT *y, FLOAT *alpha)
{
	BLASLONG i;
	FLOAT *a0,*a1,*a2,*a3;
	FLOAT x[4];
	a0 = ap[0];
	a1 = ap[1];
	a2 = ap[2];
	a3 = ap[3];

	for ( i=0; i<4; i++)
		x[i] = xo[i] * *alpha;

	for ( i=0; i< n; i+=4 )
	{
		y[i] += a0[i]*x[0] + a1[i]*x[1] + a2[i]*x[2] + a3[i]*x[3];		
		y[i+1] += a0[i+1]*x[0] + a1[i+1]*x[1] + a2[i+1]*x[2] + a3[i+1]*x[3];		
		y[i+2] += a0[i+2]*x[0] + a1[i+2]*x[1] + a2[i+2]*x[2] + a3[i+2]*x[3];		
		y[i+3] += a0[i+3]*x[0] + a1[i+3]*x[1] + a2[i+3]*x[2] + a3[i+3]*x[3];		
	}
}
	
#endif

#ifndef HAVE_KERNEL_4x2

static void dgemv_kernel_4x2( BLASLONG n, FLOAT **ap, FLOAT *x, FLOAT *y, FLOAT *alpha) __attribute__ ((noinline));

static void dgemv_kernel_4x2( BLASLONG n, FLOAT **ap, FLOAT *x, FLOAT *y, FLOAT *alpha)
{

	BLASLONG register i = 0;

	__asm__  __volatile__
	(
	"movsd    (%2)  , %%xmm12	 \n\t"	// x0 
	"movsd    (%6)  , %%xmm4 	 \n\t"	// alpha 
	"movsd   8(%2)  , %%xmm13	 \n\t"	// x1 
        "mulsd  %%xmm4  , %%xmm12        \n\t"  // alpha 
        "mulsd  %%xmm4  , %%xmm13        \n\t"  // alpha 
	"shufpd $0,  %%xmm12, %%xmm12    \n\t"	
	"shufpd $0,  %%xmm13, %%xmm13    \n\t"	

	//	".align 16				       \n\t"
	"1:				       \n\t"
	"movups	       (%3,%0,8), %%xmm4	       \n\t"	// 2 * y
	"movups	     16(%3,%0,8), %%xmm5	       \n\t"	// 2 * y

	"movups             (%4,%0,8), %%xmm8          \n\t" 
	"movups             (%5,%0,8), %%xmm9          \n\t" 
	"mulpd		%%xmm12, %%xmm8		       \n\t"
	"mulpd		%%xmm13, %%xmm9		       \n\t"
	"addpd		%%xmm8 , %%xmm4		       \n\t"
	"addpd		%%xmm9 , %%xmm4		       \n\t"

	"movups           16(%4,%0,8), %%xmm8          \n\t" 
	"movups           16(%5,%0,8), %%xmm9          \n\t" 
	"mulpd		%%xmm12, %%xmm8		       \n\t"
	"mulpd		%%xmm13, %%xmm9		       \n\t"
	"addpd		%%xmm8 , %%xmm5		       \n\t"
	"addpd		%%xmm9 , %%xmm5		       \n\t"

	"movups  %%xmm4 ,   (%3,%0,8)		       \n\t"	// 2 * y
	"movups  %%xmm5 , 16(%3,%0,8)		       \n\t"	// 2 * y

        "addq		$4 , %0	  	 	       \n\t"
	"subq	        $4 , %1			       \n\t"		
	"jnz		1b		       \n\t"

	:
        : 
          "r" (i),	// 0	
	  "r" (n),  	// 1
          "r" (x),      // 2
          "r" (y),      // 3
          "r" (ap[0]),  // 4
          "r" (ap[1]),  // 5
          "r" (alpha)   // 6
	: "cc", 
	  "%xmm4", "%xmm5", 
	  "%xmm6", "%xmm7", 
	  "%xmm8", "%xmm9", "%xmm10", "%xmm11",
	  "%xmm12", "%xmm13", "%xmm14", "%xmm15",
	  "memory"
	);

} 

#endif

#ifndef HAVE_KERNEL_4x1

static void dgemv_kernel_4x1(BLASLONG n, FLOAT *ap, FLOAT *x, FLOAT *y, FLOAT *alpha) __attribute__ ((noinline));

static void dgemv_kernel_4x1(BLASLONG n, FLOAT *ap, FLOAT *x, FLOAT *y, FLOAT *alpha)
{

        BLASLONG register i = 0;

        __asm__  __volatile__
        (
        "movsd          (%2), %%xmm12            \n\t"  // x0 
        "mulsd          (%5), %%xmm12            \n\t"  // alpha 
        "shufpd $0,  %%xmm12, %%xmm12            \n\t"

	//        ".align 16                               \n\t"
        "1:                             \n\t"
        "movups       (%4,%0,8), %%xmm8          \n\t"  // 2 * a
        "movups     16(%4,%0,8), %%xmm9          \n\t"  // 2 * a
        "movups       (%3,%0,8), %%xmm4          \n\t"  // 2 * y
        "movups     16(%3,%0,8), %%xmm5          \n\t"  // 2 * y
	"mulpd          %%xmm12, %%xmm8          \n\t"
	"mulpd          %%xmm12, %%xmm9          \n\t"
        "addpd          %%xmm8 , %%xmm4          \n\t"
        "addpd          %%xmm9 , %%xmm5          \n\t"

	"movups  %%xmm4 ,    (%3,%0,8)           \n\t"    // 2 * y
	"movups  %%xmm5 ,  16(%3,%0,8)           \n\t"    // 2 * y

        "addq           $4 , %0                  \n\t"
        "subq           $4 , %1                  \n\t"

        "jnz            1b               \n\t"

        :
        :
          "r" (i),      // 0    
          "r" (n),      // 1
          "r" (x),      // 2
          "r" (y),      // 3
          "r" (ap),     // 4
          "r" (alpha)   // 5
        : "cc",
          "%xmm4", "%xmm5",
          "%xmm6", "%xmm7",
          "%xmm8", "%xmm9", "%xmm10", "%xmm11",
          "%xmm12", "%xmm13", "%xmm14", "%xmm15",
          "memory"
        );

}

#endif

static void add_y(BLASLONG n, FLOAT *src, FLOAT *dest, BLASLONG inc_dest) __attribute__ ((noinline));

static void add_y(BLASLONG n, FLOAT *src, FLOAT *dest, BLASLONG inc_dest)
{
	BLASLONG i;
	if ( inc_dest != 1 )
	{
		for ( i=0; i<n; i++ )
		{
			*dest += *src;
			src++;
			dest += inc_dest;
		}
		return;
	}

}

int CNAME(BLASLONG m, BLASLONG n, BLASLONG dummy1, FLOAT alpha, FLOAT *a, BLASLONG lda, FLOAT *x, BLASLONG inc_x, FLOAT *y, BLASLONG inc_y, FLOAT *buffer)
{
	BLASLONG i;
	BLASLONG j;
	FLOAT *a_ptr;
	FLOAT *x_ptr;
	FLOAT *y_ptr;
	FLOAT *ap[4];
	BLASLONG n1;
	BLASLONG m1;
	BLASLONG m2;
	BLASLONG m3;
	BLASLONG n2;
	BLASLONG lda4 =  lda << 2;
	FLOAT xbuffer[8],*ybuffer;

        if ( m < 1 ) return(0);
        if ( n < 1 ) return(0);

	ybuffer = buffer;
	
	n1 = n >> 2 ;
	n2 = n &  3 ;

        m3 = m & 3  ;
        m1 = m & -4 ;
        m2 = (m & (NBMAX-1)) - m3 ;

	y_ptr = y;

	BLASLONG NB = NBMAX;

	while ( NB == NBMAX )
	{
		
		m1 -= NB;
		if ( m1 < 0)
		{
			if ( m2 == 0 ) break;	
			NB = m2;
		}
		
		a_ptr = a;
		x_ptr = x;
		
		ap[0] = a_ptr;
		ap[1] = a_ptr + lda;
		ap[2] = ap[1] + lda;
		ap[3] = ap[2] + lda;

		if ( inc_y != 1 )
			memset(ybuffer,0,NB*8);
		else
			ybuffer = y_ptr;

		if ( inc_x == 1 )
		{


			for( i = 0; i < n1 ; i++)
			{
				dgemv_kernel_4x4(NB,ap,x_ptr,ybuffer,&alpha);
				ap[0] += lda4; 
				ap[1] += lda4; 
				ap[2] += lda4; 
				ap[3] += lda4; 
				a_ptr += lda4;
				x_ptr += 4;	
			}

			if ( n2 & 2 )
			{
				dgemv_kernel_4x2(NB,ap,x_ptr,ybuffer,&alpha);
				a_ptr += lda*2;
				x_ptr += 2;	
			}


			if ( n2 & 1 )
			{
				dgemv_kernel_4x1(NB,a_ptr,x_ptr,ybuffer,&alpha);
				a_ptr += lda;
				x_ptr += 1;	

			}


		}
		else
		{

			for( i = 0; i < n1 ; i++)
			{
				xbuffer[0] = x_ptr[0];
				x_ptr += inc_x;	
				xbuffer[1] =  x_ptr[0];
				x_ptr += inc_x;	
				xbuffer[2] =  x_ptr[0];
				x_ptr += inc_x;	
				xbuffer[3] = x_ptr[0];
				x_ptr += inc_x;	
				dgemv_kernel_4x4(NB,ap,xbuffer,ybuffer,&alpha);
				ap[0] += lda4; 
				ap[1] += lda4; 
				ap[2] += lda4; 
				ap[3] += lda4; 
				a_ptr += lda4;
			}

			for( i = 0; i < n2 ; i++)
			{
				xbuffer[0] = x_ptr[0];
				x_ptr += inc_x;	
				dgemv_kernel_4x1(NB,a_ptr,xbuffer,ybuffer,&alpha);
				a_ptr += lda;

			}

		}

		a     += NB;
		if ( inc_y != 1 )
		{
			add_y(NB,ybuffer,y_ptr,inc_y);
			y_ptr += NB * inc_y;
		}
		else
			y_ptr += NB ;

	}

	if ( m3 == 0 ) return(0);

	if ( m3 == 3 )
	{
		a_ptr = a;
		x_ptr = x;
		FLOAT temp0 = 0.0;
		FLOAT temp1 = 0.0;
		FLOAT temp2 = 0.0;
		if ( lda == 3 && inc_x ==1 )
		{

			for( i = 0; i < ( n & -4 ); i+=4 )
			{

				temp0 += a_ptr[0] * x_ptr[0] + a_ptr[3] * x_ptr[1];
				temp1 += a_ptr[1] * x_ptr[0] + a_ptr[4] * x_ptr[1];
				temp2 += a_ptr[2] * x_ptr[0] + a_ptr[5] * x_ptr[1];

				temp0 += a_ptr[6] * x_ptr[2] + a_ptr[9]  * x_ptr[3];
				temp1 += a_ptr[7] * x_ptr[2] + a_ptr[10] * x_ptr[3];
				temp2 += a_ptr[8] * x_ptr[2] + a_ptr[11] * x_ptr[3];

				a_ptr += 12;
				x_ptr += 4;
			}

			for( ; i < n; i++ )
			{
				temp0 += a_ptr[0] * x_ptr[0];
				temp1 += a_ptr[1] * x_ptr[0];
				temp2 += a_ptr[2] * x_ptr[0];
				a_ptr += 3;
				x_ptr ++;
			}

		}
		else
		{

			for( i = 0; i < n; i++ )
			{
				temp0 += a_ptr[0] * x_ptr[0];
				temp1 += a_ptr[1] * x_ptr[0];
				temp2 += a_ptr[2] * x_ptr[0];
				a_ptr += lda;
				x_ptr += inc_x;


			}

		}
		y_ptr[0] += alpha * temp0;
		y_ptr += inc_y;
		y_ptr[0] += alpha * temp1;
		y_ptr += inc_y;
		y_ptr[0] += alpha * temp2;
		return(0);
	}


	if ( m3 == 2 )
	{
		a_ptr = a;
		x_ptr = x;
		FLOAT temp0 = 0.0;
		FLOAT temp1 = 0.0;
		if ( lda == 2 && inc_x ==1 )
		{

			for( i = 0; i < (n & -4) ; i+=4 )
			{
				temp0 += a_ptr[0] * x_ptr[0] + a_ptr[2] * x_ptr[1];
				temp1 += a_ptr[1] * x_ptr[0] + a_ptr[3] * x_ptr[1];
				temp0 += a_ptr[4] * x_ptr[2] + a_ptr[6] * x_ptr[3];
				temp1 += a_ptr[5] * x_ptr[2] + a_ptr[7] * x_ptr[3];
				a_ptr += 8;
				x_ptr += 4;

			}


			for( ; i < n; i++ )
			{
				temp0 += a_ptr[0]   * x_ptr[0];
				temp1 += a_ptr[1]   * x_ptr[0];
				a_ptr += 2;
				x_ptr ++;
			}

		}
		else
		{

			for( i = 0; i < n; i++ )
			{
				temp0 += a_ptr[0] * x_ptr[0];
				temp1 += a_ptr[1] * x_ptr[0];
				a_ptr += lda;
				x_ptr += inc_x;


			}

		}
		y_ptr[0] += alpha * temp0;
		y_ptr += inc_y;
		y_ptr[0] += alpha * temp1;
		return(0);
	}

	if ( m3 == 1 )
	{
		a_ptr = a;
		x_ptr = x;
		FLOAT temp = 0.0;
		if ( lda == 1 && inc_x ==1 )
		{

			for( i = 0; i < (n & -4); i+=4 )
			{
				temp += a_ptr[i] * x_ptr[i] + a_ptr[i+1] * x_ptr[i+1] + a_ptr[i+2] * x_ptr[i+2] + a_ptr[i+3] * x_ptr[i+3];
	
			}

			for( ; i < n; i++ )
			{
				temp += a_ptr[i] * x_ptr[i];
			}

		}
		else
		{

			for( i = 0; i < n; i++ )
			{
				temp += a_ptr[0] * x_ptr[0];
				a_ptr += lda;
				x_ptr += inc_x;
			}

		}
		y_ptr[0] += alpha * temp;
		return(0);
	}


	return(0);
}