[Bug middle-end/57748] [4.7/4.8/4.9 Regression] ICE when expanding assignment to unaligned zero-sized array

[bernd.edlinger at hotmail dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57748

--- Comment #35 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
Well, this bug seems to have a symmetical twin on the read side.

In the above example, if I add this:

  if (x->xx[0].b != 3.14F || x->xx[1].a != 0x123456789ABCDEF)
    abort ();

this gets compiled:

        movdqu  (%rdi), %xmm0
        ucomiss .LC0(%rip), %xmm0
        jp      .L2
        jne     .L2
        movdqu  (%rdi), %xmm0
        movabsq $81985529216486895, %rdx
        movhlps %xmm0, %xmm1
        movq    %xmm1, %rax
        cmpq    %rdx, %rax
        jne     .L2

regardless if x is volatile or even with -fstrict-volatile-bitfields (!)