gcc/testsuite/gcc.target/i386/pieces-memset-2.c

/* { dg-do compile } */
/* { dg-options "-O2 -mno-avx2 -mavx -mtune-ctrl=avx256_store_by_pieces" } */

extern char *dst;

void
foo (int x)
{
  __builtin_memset (dst, x, 64);
}

/* { dg-final { scan-assembler-times "vmovdqu\[ \\t\]+\[^\n\]*%ymm" 2 } } */