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The fastest sorting algorithm for millions of graphic pixels UINT64 RGBZ

I sort 10+ millions uint64_twith RGB data from .RAW files and 79% of my C program time is spent on qsort. I am looking for a faster view for this particular data type.

Being RAW graphic data, the numbers are very random and ~ 80% unique. No partial sorting or run of sorted data is expected. 4 uint16_tinside uint64_tare equal to R, G, B and zero (possibly a small number <= ~ 20).

I have the simplest comparison function that I can come up with unsigned long long(you CANNOT just subtract them):

qsort(hpidx, num_pix, sizeof(uint64_t), comp_uint64); 
...
int comp_uint64(const void *a, const void *b)  {
    if(*((uint64_t *)a) > *((uint64_t *)b))  return(+1);
    if(*((uint64_t *)a) < *((uint64_t *)b))  return(-1);
    return(0);
}  // End Comp_uint64().

StackExchange came up with a very interesting "Puzzle Programming and Code Golf", but they used floats. Then there are QSort, RecQuick, heap, stooge, tree, radix ...

Swenson / sort looked interesting, but did not have (obviously) Support for my type of data uint64_t. And the time of "quick sort" was the best. Some sources say the system qsortcan be anything, not necessarily “Quick Sort”.

The C ++ variety bypasses the general void pointer listing and implements major performance improvements over C. There must be an optimized method for hacking U8 through a 64-bit processor with a strain rate.

System / Compiler Information:

I am currently using GCC with Strawberry Perl

gcc version 4.9.2 (x86_64-posix-sjlj, built by strawberryperl.com
Intel 2700K Sandy Bridge CPU, 32GB DDR3
windows 7/64 pro

gcc -D__USE_MINGW_ANSI_STDIO -O4 -ffast-math -m64 -Ofast -march=corei7-avx -mtune=corei7 -Ic:/bin/xxHash-master -Lc:/bin/xxHash-master c:/bin/stddev.c -o c:/bin/stddev.g6.exe

The first attempt to improve qsort, QSORT()!

inline qsort.

"READY-TO-USE"? qsort.h

-----------------------------
* Several ready-to-use examples:
 *
 * Sorting array of integers:
 * void int_qsort(int *arr, unsigned n) {
 * #define int_lt(a,b) ((*a)<(*b))
 *   QSORT(int, arr, n, int_lt);
--------------------------------

Change from type "int" to "uint64_t"
compile error on TYPE???

    c:/bin/bpbfct.c:586:8: error: expected expression before 'uint64_t'
      QSORT(uint64_t, hpidx, num_pix, islt);

, , , " "

#define QSORT_TYPE uint64_t 
#define islt(a,b) ((*a)<(*b))

uint64_t *QSORT_BASE; 
int QSORT_NELT;

hpidx=(uint64_t *) calloc(num_pix+2, sizeof(uint64_t));  // Hash . PIDX
QSORT_BASE = hpidx;
QSORT_NELT = num_pix;  // QSORT_LT is function QSORT_LT()
QSORT(uint64_t, hpidx, num_pix, islt);  
//QSORT(uint64_t *, hpidx, num_pix, QSORT_LT);  // QSORT_LT mal-defined?
//qsort(hpidx, num_pix, sizeof(uint64_t), comp_uint64); // << WORKS

" " int, char * struct elt. uint64_t ? long long

QSORT(long long, hpidx, num_pix, islt); 
c:/bin/bpbfct.c:586:8: error: expected expression before 'long'
 QSORT(long long, hpidx, num_pix, islt);

: RADIXSORT:

: RADIX_SORT !

  I:\br3\pf.249465>grep "Event" bb12.log | grep -i Sort       
 << 1.40 sec average
4) Time=1.411 sec    = 49.61%, Event RADIX_SORT        , hits=1
4) Time=1.396 sec    = 49.13%, Event RADIX_SORT        , hits=1
4) Time=1.392 sec    = 49.15%, Event RADIX_SORT        , hits=1
16) Time=1.414 sec    = 49.12%, Event RADIX_SORT        , hits=1

I:\br3\pf.249465>grep "Event" bb11.log | grep -i Sort 
 << 5.525 sec average  = 3.95 time slower
4) Time=5.538 sec    = 86.34%, Event QSort             , hits=1
4) Time=5.519 sec    = 79.41%, Event QSort             , hits=1
4) Time=5.519 sec    = 79.02%, Event QSort             , hits=1
4) Time=5.563 sec    = 79.49%, Event QSort             , hits=1
4) Time=5.684 sec    = 79.83%, Event QSort             , hits=1
4) Time=5.509 sec    = 79.30%, Event QSort             , hits=1

3,94 , qsort !

, , , 80% , - , , , , 20%.

! !

+4
4

Radix Sort 8- . 64- 9 ( 8 64 /8 ). 9 * N 2 * N ( ).

radix.

typedef union {
    struct {
        uint32_t c8[256];
        uint32_t c7[256];
        uint32_t c6[256];
        uint32_t c5[256];
        uint32_t c4[256];
        uint32_t c3[256];
        uint32_t c2[256];
        uint32_t c1[256];
    };
    uint32_t counts[256 * 8];
} rscounts_t;

uint64_t * radixSort(uint64_t * array, uint32_t size) {
    rscounts_t counts;
    memset(&counts, 0, 256 * 8 * sizeof(uint32_t));
    uint64_t * cpy = (uint64_t *)malloc(size * sizeof(uint64_t));
    uint32_t o8=0, o7=0, o6=0, o5=0, o4=0, o3=0, o2=0, o1=0;
    uint32_t t8, t7, t6, t5, t4, t3, t2, t1;
    uint32_t x;
    // calculate counts
    for(x = 0; x < size; x++) {
        t8 = array[x] & 0xff;
        t7 = (array[x] >> 8) & 0xff;
        t6 = (array[x] >> 16) & 0xff;
        t5 = (array[x] >> 24) & 0xff;
        t4 = (array[x] >> 32) & 0xff;
        t3 = (array[x] >> 40) & 0xff;
        t2 = (array[x] >> 48) & 0xff;
        t1 = (array[x] >> 56) & 0xff;
        counts.c8[t8]++;
        counts.c7[t7]++;
        counts.c6[t6]++;
        counts.c5[t5]++;
        counts.c4[t4]++;
        counts.c3[t3]++;
        counts.c2[t2]++;
        counts.c1[t1]++;
    }
    // convert counts to offsets
    for(x = 0; x < 256; x++) {
        t8 = o8 + counts.c8[x];
        t7 = o7 + counts.c7[x];
        t6 = o6 + counts.c6[x];
        t5 = o5 + counts.c5[x];
        t4 = o4 + counts.c4[x];
        t3 = o3 + counts.c3[x];
        t2 = o2 + counts.c2[x];
        t1 = o1 + counts.c1[x];
        counts.c8[x] = o8;
        counts.c7[x] = o7;
        counts.c6[x] = o6;
        counts.c5[x] = o5;
        counts.c4[x] = o4;
        counts.c3[x] = o3;
        counts.c2[x] = o2;
        counts.c1[x] = o1;
        o8 = t8; 
        o7 = t7; 
        o6 = t6; 
        o5 = t5; 
        o4 = t4; 
        o3 = t3; 
        o2 = t2; 
        o1 = t1;
    }
    // radix
    for(x = 0; x < size; x++) {
        t8 = array[x] & 0xff;
        cpy[counts.c8[t8]] = array[x];
        counts.c8[t8]++;
    }
    for(x = 0; x < size; x++) {
        t7 = (cpy[x] >> 8) & 0xff;
        array[counts.c7[t7]] = cpy[x];
        counts.c7[t7]++;
    }
    for(x = 0; x < size; x++) {
        t6 = (array[x] >> 16) & 0xff;
        cpy[counts.c6[t6]] = array[x];
        counts.c6[t6]++;
    }
    for(x = 0; x < size; x++) {
        t5 = (cpy[x] >> 24) & 0xff;
        array[counts.c5[t5]] = cpy[x];
        counts.c5[t5]++;
    }
    for(x = 0; x < size; x++) {
        t4 = (array[x] >> 32) & 0xff;
        cpy[counts.c4[t4]] = array[x];
        counts.c4[t4]++;
    }
    for(x = 0; x < size; x++) {
        t3 = (cpy[x] >> 40) & 0xff;
        array[counts.c3[t3]] = cpy[x];
        counts.c3[t3]++;
    }
    for(x = 0; x < size; x++) {
        t2 = (array[x] >> 48) & 0xff;
        cpy[counts.c2[t2]] = array[x];
        counts.c2[t2]++;
    }
    for(x = 0; x < size; x++) {
        t1 = (cpy[x] >> 56) & 0xff;
        array[counts.c1[t1]] = cpy[x];
        counts.c1[t1]++;
    }
    free(cpy);
    return array;
}

EDIT JavaScript 32- JavaScript?

IDEONE C http://ideone.com/JHI0d9

+8

, .

, . , , .

+4

With some compilers / platforms, the following is branchless and faster, although not much different from the original OP.

int comp_uint64_b(const void *a, const void *b)  {
    return 
     (*((uint64_t *)a) > *((uint64_t *)b)) - 
     (*((uint64_t *)a) < *((uint64_t *)b));
}
+2
source

Maybe some ?: instead of ifs, they will do things a little faster.

-3
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