gcsort.c

#include <stdio.h>
#include <stdlib.h>

// An radix 2 sort with nice properties.
void sort(unsigned *a, int len)
{
  unsigned *s = a, *d = malloc(len * sizeof *d), *t, bit, is, id0, id1;

  for (bit = 1; bit; bit <<= 1, t = s, s = d, d = t)
    for (is = id0 = 0, id1 = len; is < len; ++is)
      d[((s[is] >> 1) ^ s[is]) & bit ? --id1 : id0++] = s[is];
  free(d);
}