OSchip
/
OpenBLAS

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#include "common.h"
#include <math.h>
#include <altivec.h>
#if defined(DOUBLE)

#define ABS fabs

#else

#define ABS fabsf

#endif

/**
 * Find  maximum index 
 * Warning: requirements n>0  and n % 32 == 0
 * @param n     
 * @param x     pointer to the vector
 * @param maxf  (out) maximum absolute value .( only for output )
 * @return  index 
 */
static BLASLONG diamax_kernel_32(BLASLONG n, FLOAT *x, FLOAT *maxf) {
    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_max_index
            "vaddudm  11,10,%[adder] \n\t" //{7,6} vs43
            "xxlxor  39,39,39        \n\t" //   vs39 vec_max_value
            "vaddudm 4,11,  %[adder] \n\t" // {9,8} -{8;8} vs36 | v4
            XXSPLTD_S(36,36,0)
    
            "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  2,45,44  \n\t "
            "xvcmpgtdp  3,47,46  \n\t "
            "xvcmpgtdp  4,49,48  \n\t "
            "xvcmpgtdp  5,7,6  \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, 1,0     \n\t"
            "xvcmpgtdp 3,47, 45   \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 bigger from first and second part
            "xvcmpgtdp 4,5 , 0    \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 bigger  

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

            //compare with previous to get vec_max_index(v6 | vs38 ) and vec_max_value (vs39)   
            "xvcmpgtdp 2, 3,39    \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  2,45,44  \n\t "
            "xvcmpgtdp  3,47,46  \n\t "
            "xvcmpgtdp  4,49,48  \n\t "
            "xvcmpgtdp  5,7,6  \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, 1,0     \n\t"
            "xvcmpgtdp 3,47, 45   \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 bigger from first and second part
            "xvcmpgtdp 4,5 , 0    \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 bigger  

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

 
            //compare with previous to get vec_max_index(v6 | vs38 ) and vec_max_value (vs39)   
            "xvcmpgtdp 2, 3,39    \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  2,45,44  \n\t "
            "xvcmpgtdp  3,47,46  \n\t "
            "xvcmpgtdp  4,49,48  \n\t "
            "xvcmpgtdp  5,7,6  \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, 1,0     \n\t"
            "xvcmpgtdp 3,47, 45   \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 bigger from first and second part
            "xvcmpgtdp 4,5 , 0    \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 bigger   

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

            ///////extract max value and max 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, 40,39  \n\t"
            "xxsel    0,39,40,4           \n\t"
            "xxsel    1,38,32,4  \n\t"
            "stxsdx    0,0,%[ptr_maxf]     \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_maxf]  \n\t"
          

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

            : [maxf] "=m"(*maxf),[ptr_tmp] "+&b"(x),[index] "=r"(index), [n] "+&r"(n)
            : [mem] "m"(*(const double (*)[n])x), [ptr_x] "b"(x), [ptr_maxf] "b"(maxf) ,
            [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;
    FLOAT maxf = 0.0;
    BLASLONG max = 0;

    if (n <= 0 || inc_x <= 0) return (max);

    if (inc_x == 1) {

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

            max = diamax_kernel_32(n1, x, &maxf);

            i = n1;
        }

        while (i < n) {
            if (ABS(x[i]) > maxf) {
                max = i;
                maxf = ABS(x[i]);
            }
            i++;
        }
        return (max + 1);

    } else {

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

            if (ABS(x[i]) > maxf) {
                max = j;
                maxf = ABS(x[i]);
            }
            if (ABS(x[i + inc_x]) > maxf) {
                max = j + 1;
                maxf = ABS(x[i + inc_x]);
            }
            if (ABS(x[i + 2 * inc_x]) > maxf) {
                max = j + 2;
                maxf = ABS(x[i + 2 * inc_x]);
            }
            if (ABS(x[i + 3 * inc_x]) > maxf) {
                max = j + 3;
                maxf = ABS(x[i + 3 * inc_x]);
            }

            i += inc_x * 4;

            j += 4;

        }


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