OSchip
/
OpenBLAS

/***************************************************************************
Copyright (c) 2013-2018, The OpenBLAS Project
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 *****************************************************************************/
#include "common.h"
#include <math.h>

#if defined(DOUBLE)

#define ABS fabs

#else

#define ABS fabsf

#endif

/**
 * Find  minimum index 
 * Warning: requirements n>0  and n % 32 == 0
 * @param n     
 * @param x     pointer to the vector
 * @param minf  (out) minimum absolute value .( only for output )
 * @return minimum index 
 */
static BLASLONG diamin_kernel_32(BLASLONG n, FLOAT *x, FLOAT *minf) {
    BLASLONG index;
    register __vector long long start = {1,0};
    register __vector long long temp_add_index = {2, 2}; 
    __asm__(
 

            "lxvd2x  44,      0,%[ptr_tmp] \n\t"
            "lxvd2x  45, %[i16],%[ptr_tmp] \n\t"
            "lxvd2x  46, %[i32],%[ptr_tmp] \n\t"
            "lxvd2x  47, %[i48],%[ptr_tmp] \n\t" 
            "lxvd2x  48, %[i64],%[ptr_tmp] \n\t"
            "lxvd2x  49, %[i80],%[ptr_tmp] \n\t"
            "lxvd2x  6, %[i96],%[ptr_tmp] \n\t"
            "lxvd2x  7,%[i112],%[ptr_tmp] \n\t"

            "xxlor  40,%x[start],%x[start]  \n\t" //{ 1,0} vs40 | v8 
            "vaddudm  9,8, %[adder]   \n\t" //{3,2} vs41 
            "xxlxor  37,37 ,37        \n\t" //v5 v37 index_count
            "vaddudm  10,9,%[adder]   \n\t" //{5,4} vs42
            "xxlxor  38 ,38 ,38       \n\t"  // v6 | vs38 vec_min_index
            "vaddudm  11,10,%[adder]  \n\t" //{7,6} vs43
            "lxvdsx  39,0,%[ptr_minf] \n\t" //   vs39 vec_min_value
            "vaddudm  4,11, %[adder]  \n\t" // {9,8} -{8;8} vs36 | v4
            XXSPLTD_S(36,36,0)
            "xvabsdp  39, 39 \n\t"             
    
            "xvabsdp  44, 44 \n\t"
            "xvabsdp  45, 45 \n\t"
            "xvabsdp  46, 46 \n\t"
            "xvabsdp  47, 47 \n\t"                         
            "xvabsdp  48, 48 \n\t"
            "xvabsdp  49, 49 \n\t"
            "xvabsdp  6, 6 \n\t"
            "xvabsdp  7, 7 \n\t"
  
            //jump first half forward 
            "b two%=  \n\t"

//===================================================================

            ".align   5            \n\t"

            "one%=: \n\t"
            "xvcmpgtdp  2,44,45  \n\t "
            "xvcmpgtdp  3,46,47  \n\t "
            "xvcmpgtdp  4,48,49  \n\t "
            "xvcmpgtdp  5,6,7  \n\t"

            "xxsel    32,40,41,2 \n\t"
            "xxsel     0,44,45,2 \n\t" 
            "xxsel    33,42,43,3 \n\t"
            "xxsel     1,46,47,3 \n\t" 
            "xxsel    34,40,41,4 \n\t"
            "xxsel    45,48,49,4 \n\t"
            "xxsel    35,42,43,5 \n\t"
            "xxsel    47,6,7,5 \n\t"

            "xvcmpgtdp 2,0, 1     \n\t"
            "xvcmpgtdp 3, 45,47   \n\t"

            "addi     %[ptr_tmp] ,%[ptr_tmp] , 128 \n\t" 
    
            "xxsel     32,32,33,2 \n\t"
            "xxsel       0 ,0,1,2 \n\t"
            "xxsel     34,34,35,3 \n\t"
            "xxsel     5,45,47,3 \n\t"
 
          
            //load next 64
            "lxvd2x  44,      0,%[ptr_tmp] \n\t"
            "lxvd2x  45, %[i16],%[ptr_tmp] \n\t"
    
            // for {second 8 elements } we have to add 8 to each so that it became {from 8 to 16}
            "vaddudm     2,2,4  \n\t" // vs34=vs34 + vs36{8,8} 
    
            "lxvd2x  46, %[i32],%[ptr_tmp] \n\t"
            "lxvd2x  47, %[i48],%[ptr_tmp] \n\t" 

            //choose smaller from first and second part
            "xvcmpgtdp 4, 0,5     \n\t" 
            "xxsel     3, 0,5,4  \n\t"
            "xxsel     33,32,34,4  \n\t"

            //load next 64
            "lxvd2x  48, %[i64],%[ptr_tmp] \n\t"
            "lxvd2x  49, %[i80],%[ptr_tmp] \n\t"

            "vaddudm  1,1,5  \n\t"  //  get real index for first smaller  

            "lxvd2x  6, %[i96],%[ptr_tmp] \n\t"
            "lxvd2x  7,%[i112],%[ptr_tmp] \n\t"

            //compare with previous to get vec_min_index(v6 | vs38 ) and vec_min_value (vs39)   
            "xvcmpgtdp 2,39, 3    \n\t"
            "xxsel     39,39,3,2  \n\t"
            "xxsel     38,38,33,2  \n\t"
    
            //update index += 8 
            "vaddudm   5,5,4       \n\t"  

            "xvabsdp  44, 44 \n\t"
            "xvabsdp  45, 45 \n\t"
            "xvabsdp  46, 46 \n\t"
            "xvabsdp  47, 47 \n\t"   

            //update index += 8 
            "vaddudm   5,5,4       \n\t"  

            "xvabsdp  48, 48 \n\t"
            "xvabsdp  49, 49 \n\t"
            "xvabsdp  6, 6 \n\t"
            "xvabsdp  7, 7 \n\t"

//<-----------jump here from first load
             "two%=:                  \n\t"
    
            "xvcmpgtdp  2,44,45  \n\t "
            "xvcmpgtdp  3,46,47  \n\t "
            "xvcmpgtdp  4,48,49  \n\t "
            "xvcmpgtdp  5,6,7  \n\t"

            "xxsel    32,40,41,2 \n\t"
            "xxsel     0,44,45,2 \n\t" 
            "xxsel    33,42,43,3 \n\t"
            "xxsel     1,46,47,3 \n\t" 
            "xxsel    34,40,41,4 \n\t"
            "xxsel    45,48,49,4 \n\t"
            "xxsel    35,42,43,5 \n\t"
            "xxsel    47,6,7,5 \n\t"

            "xvcmpgtdp 2,0, 1     \n\t"
            "xvcmpgtdp 3, 45,47   \n\t"
            "xxsel     32,32,33,2 \n\t"
            "xxsel       0 ,0,1,2 \n\t"
            "xxsel     34,34,35,3 \n\t"
            "xxsel     5,45,47,3 \n\t"

            "addi     %[ptr_tmp] ,%[ptr_tmp] , 128 \n\t" 
            // for {second 8 elements } we have to add 8 to each so that it became {from 8 to 16}
            "vaddudm     2,2,4  \n\t" // vs34=vs34 + vs36{8,8} 
          
            //load next 64
            "lxvd2x  44,      0,%[ptr_tmp] \n\t"
            "lxvd2x  45, %[i16],%[ptr_tmp] \n\t"
            "lxvd2x  46, %[i32],%[ptr_tmp] \n\t"
            "lxvd2x  47, %[i48],%[ptr_tmp] \n\t" 

            //choose smaller from first and second part
            "xvcmpgtdp 4, 0,5     \n\t" 
            "xxsel     3, 0,5,4  \n\t"
            "xxsel     33,32,34,4  \n\t"

            //load next 64
            "lxvd2x  48, %[i64],%[ptr_tmp] \n\t"
            "lxvd2x  49, %[i80],%[ptr_tmp] \n\t"

            "vaddudm  1,1,5  \n\t"  //  get real index for first smaller  

            "lxvd2x  6, %[i96],%[ptr_tmp] \n\t"
            "lxvd2x  7,%[i112],%[ptr_tmp] \n\t"

 
            //compare with previous to get vec_min_index(v6 | vs38 ) and vec_min_value (vs39)   
            "xvcmpgtdp 2,39, 3    \n\t"
            "xxsel     39,39,3,2  \n\t"
            "xxsel     38,38,33,2  \n\t"
    
            //update index += 8 
            "vaddudm   5,5,4       \n\t"  

            "xvabsdp  44, 44 \n\t"
            "xvabsdp  45, 45 \n\t"
            "xvabsdp  46, 46 \n\t"
            "xvabsdp  47, 47 \n\t"   

            //update index += 8 
            "vaddudm   5,5,4       \n\t"  

            "xvabsdp  48, 48 \n\t"
            "xvabsdp  49, 49 \n\t"
            "xvabsdp  6, 6 \n\t"
            "xvabsdp  7, 7 \n\t"

            //decrement n
            "addic.    %[n], %[n], -32 \n\t"
           
            //Loop back if >0
            "bgt+ one%=  \n\t"

//==============================================================================

            "xvcmpgtdp  2,44,45  \n\t "
            "xvcmpgtdp  3,46,47  \n\t "
            "xvcmpgtdp  4,48,49  \n\t "
            "xvcmpgtdp  5,6,7  \n\t"

            "xxsel    32,40,41,2 \n\t"
            "xxsel     0,44,45,2 \n\t" 
            "xxsel    33,42,43,3 \n\t"
            "xxsel     1,46,47,3 \n\t" 
            "xxsel    34,40,41,4 \n\t"
            "xxsel    45,48,49,4 \n\t"
            "xxsel    35,42,43,5 \n\t"
            "xxsel    47,6,7,5 \n\t"

            "xvcmpgtdp 2,0, 1     \n\t"
            "xvcmpgtdp 3, 45,47   \n\t"
  
    
            "xxsel     32,32,33,2 \n\t"
            "xxsel       0 ,0,1,2 \n\t"
            "xxsel     34,34,35,3 \n\t"
            "xxsel     5,45,47,3 \n\t" 
    
            // for {second 8 elements } we have to add 8 to each so that it became {from 8 to 16}
            "vaddudm     2,2,4  \n\t" // vs34=vs34 + vs36{8,8}  
            //choose smaller from first and second part
            "xvcmpgtdp 4, 0,5     \n\t" 
            "xxsel     3, 0,5,4   \n\t"
            "xxsel     33,32,34,4 \n\t" 

            "vaddudm  1,1,5  \n\t"  //  get real index for first smaller   

            //compare with previous to get vec_min_index(v6 | vs38 ) and vec_min_value (vs39)   
            "xvcmpgtdp 2,39, 3    \n\t"
            "xxsel     39,39,3,2  \n\t"
            "xxsel     38,38,33,2  \n\t"

            ///////extract min value and min index from vector

            XXSPLTD_S(32,38,1)
            XXSPLTD_S(40,39,1)
            "xvcmpeqdp.  2, 40,39  \n\t"
    
            //cr6 0 bit set if all true, cr6=4*6+bit_ind=24,0011at CR(BI)==1, at=10 hint that it occurs rarely
             //0b001110=14
            "bc 14,24, three%=  \n\t" 
            "xvcmpgtdp  4,39, 40  \n\t"
            "xxsel    0,39,40,4           \n\t"
            "xxsel    1,38,32,4  \n\t"
            "stxsdx    0,0,%[ptr_minf]     \n\t" 
            "b four%=    \n\t"

            "three%=:      \n\t" 
                //if elements value are equal then choose minimum index
            XXSPLTD_S(0,40,0)
            "vminud   0,0,6    \n\t"  //vs32 vs38
            "xxlor 1,32,32     \n\t"
            "stxsdx   0,0,%[ptr_minf]  \n\t"
          

            "four%=:      \n\t"
            "mfvsrd   %[index],1 \n\t"

            : [minf] "=m"(*minf),[ptr_tmp] "+&b"(x),[index] "=r"(index), [n] "+&r"(n)
            : [mem] "m"(*(const double (*)[n])x), [ptr_x] "b"(x), [ptr_minf] "b"(minf) ,
            [i16] "b"(16), [i32] "b"(32), [i48] "b"(48),
            [i64] "b"(64), [i80] "b"(80), [i96] "b"(96), [i112] "b"(112),
            [start] "v"(start),  [adder] "v"(temp_add_index)
            : "cc", "vs0", "vs1","vs2","vs3", "vs4","vs5","vs32", "vs33", "vs34", "vs35", "vs36",
            "vs37", "vs38", "vs39", "vs40", "vs41", "vs42", "vs43", "vs44", "vs45", "vs46", "vs47", "vs48", "vs49", "vs6", "vs7"
            );
 
    return index;

}


BLASLONG CNAME(BLASLONG n, FLOAT *x, BLASLONG inc_x) {
    BLASLONG i = 0;
    BLASLONG j = 0; 
    BLASLONG min = 0;
    FLOAT minf = 0.0;
    
    if (n <= 0 || inc_x <= 0) return (min);
    minf = ABS(x[0]); //index's not incremented
    if (inc_x == 1) {

        BLASLONG n1 = n & -32;
        if (n1 > 0) {

            min = diamin_kernel_32(n1, x, &minf);
            i = n1;
        }

        while (i < n) {
            if (ABS(x[i]) < minf) {
                min = i;
                minf = ABS(x[i]);
            }
            i++;
        }
        return (min + 1);

    } else {

        BLASLONG n1 = n & -4;
        while (j < n1) {

            if (ABS(x[i]) < minf) {
                min = j;
                minf = ABS(x[i]);
            }
            if (ABS(x[i + inc_x]) < minf) {
                min = j + 1;
                minf = ABS(x[i + inc_x]);
            }
            if (ABS(x[i + 2 * inc_x]) < minf) {
                min = j + 2;
                minf = ABS(x[i + 2 * inc_x]);
            }
            if (ABS(x[i + 3 * inc_x]) < minf) {
                min = j + 3;
                minf = ABS(x[i + 3 * inc_x]);
            }

            i += inc_x * 4;

            j += 4;

        }


        while (j < n) {
            if (ABS(x[i]) < minf) {
                min = j;
                minf = ABS(x[i]);
            }
            i += inc_x;
            j++;
        }
        return (min + 1);
    }
}