Try Add with Carry

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

int main(void) {

int64_t a    = 9223372036854775807;
int64_t b    = 1;
int64_t res  = 0;
int64_t res2 = 0;
int64_t c = 0;

  asm("addc. %0, %1, %2 \n"
      : "=r"(res)
      : "a"(a), "b"(b));

  asm("lis %0, 256 \n"
      "ori %0, %0, 7552 \n"
      "rldicr %0, %0,16,47 \n"
      "ori %0,%0,7596 \n"
      "nop \n"
      "bc 0xC,3,there\n"
      "here:  addi %1, %1, 10\n"
      "there: addi %1, %1, 42 \n"
      : "=r"(res2),"=r"(c)
      : "a"(c));

  printf("%" PRId64 "\n", res);
  printf("%" PRId64 "\n", res2);
  printf("%" PRId64 "\n", c);
  return 0;
}