[Bug c/114080] Inconsistent handling of unaligned 128bit ints between GCC versions

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114080

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Note, most not too old compilers handle small constant size memcpy as an
efficient way to load/store unaligned values and it is also portable.  So,
instead of
  *dstp = *srcp ^ *bufp;
if all those can be unaligned use
  __uint128_t t1, t2;
  memcpy (&t1, srcp, sizeof (t1));
  memcpy (&t2, bufp, sizeof (t2));
  t1 = t1 ^ t2;
  memcpy (dstp, &t1, sizeof (t1));
should result in decent code (unless -O0 of course).