[Bug c/111779] New: Fail to vectorize the struct include struct

["juzhe.zhong at rivai dot ai" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111779

            Bug ID: 111779
           Summary: Fail to vectorize the struct include struct
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: juzhe.zhong at rivai dot ai
  Target Milestone: ---

#include <stdbool.h>
#include <assert.h>
struct C
{
    int c;
    int d;
    bool f :1;
    float e;
};

struct A
{
  unsigned int a;
  unsigned char c1, c2;
  bool b1 : 1;
  bool b2 : 1;
  bool b3 : 1;
  struct C b4;
};

void
foo (const struct A * __restrict x, int y)
{
  int s = 0, i = 0;
  for (i = 0; i < y; ++i)
    {
      const struct A a = x[i];
      s += a.b4.f ? 1 : 0;
    }
  assert (s == 0);
    //__builtin_abort ();
}

int
main ()
{
  struct A x[100];
  int i;
  __builtin_memset (x, -1, sizeof (x));
  for (i = 0; i < 100; i++)
    {
      x[i].b1 = false;
      x[i].b2 = false;
      x[i].b3 = false;
      x[i].b4.f = false;
    }
  foo (x, 100);
  return 0;
}

https://godbolt.org/z/KWb7c1n5h

Both SVE GCC and RVV GCC failed to vectorize it.
But Clang succeed on vectorization.