128test.c

#include <stdio.h>
#include <stdint.h>
#include <emmintrin.h>

void print128_num(__m128i var) 
{
    int64_t *v64val = (int64_t*) &var;
    printf("%.16lld %.16lld\n", v64val[1], v64val[0]);
}

int main() {
  __m128i var;
  var = _mm_set_epi64x(-1588454185101182573, 437384867522774919);
  print128_num(var);
}