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
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
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE OPENBLAS PROJECT OR CONTRIBUTORS BE
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*****************************************************************************/


#include "common.h"


#if defined(NEHALEM)
#include "dgemv_n_microk_nehalem-4.c"
#elif defined(HASWELL) || defined(ZEN) || defined(STEAMROLLER) || defined(EXCAVATOR)
#include "dgemv_n_microk_haswell-4.c"
#elif  defined (SKYLAKEX) || defined (COOPERLAKE) || defined (SAPPHIRERAPIDS)
#include "dgemv_n_microk_skylakex-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;
	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);
}