gcc/testsuite/gcc.target/i386/movbe-1.c

/* { dg-do compile } */
/* { dg-options "-O2 -mmovbe" } */

extern int x;

void
foo (int i)
{
  x = __builtin_bswap32 (i);
}

int
bar ()
{
  return __builtin_bswap32 (x);
}

/* { dg-final { scan-assembler-times "movbe\[ \t\]" 2 } } */