gcc/gcc/testsuite/gcc.dg/memset-2.c

/* PR target/63937 */
/* { dg-do compile { target lp64 } } */
/* { dg-options "-O2" } */

void
foo (char *p)
{
  p = __builtin_assume_aligned (p, 64);
  __builtin_memset (p, 0, 0x100000001ULL);
}