[Bug tree-optimization/71083] [5/6/7 Regression] Unaligned bit-field address when predictive commoning

["bernd.edlinger at hotmail dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71083

Bernd Edlinger <bernd.edlinger at hotmail dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bernd.edlinger at hotmail dot de

--- Comment #6 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
just wanted to add that the patch in comment#2
does not fix this similar test case:

struct lock_chain {
  char x;
  unsigned short base;
} __attribute((packed));

struct lock_chain * foo (struct lock_chain *chain)
{
  int i;
  for (i = 0; i < 100; i++)
    {
      chain[i+1].base = chain[i].base;
    }
  return chain;
}

foo:
        @ Function supports interworking.
        @ args = 0, pretend = 0, frame = 0
        @ frame_needed = 0, uses_anonymous_args = 0
        @ link register save eliminated.
        ldrh    r2, [r0, #1] <- unaligned
        add     r1, r0, #300
        and     ip, r2, #255
        add     r1, r1, #3
        lsr     r2, r2, #8
        add     r3, r0, #3
.L2:
        strb    ip, [r3, #1]
        strb    r2, [r3, #2]
        add     r3, r3, #3
        cmp     r3, r1
        bne     .L2
        bx      lr