[Bug middle-end/68360] GCC bitfield processing code is very inefficient

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68360

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
For AARCH64 GCC does a much better job:
foo:
        stp     x29, x30, [sp, -32]!
        add     x29, sp, 0
        ldrb    w1, [x29,28]
        lsr     w2, w0, 2
        bfi     w1, w2, 2, 2
        lsr     w0, w0, 6
        bfi     w1, w0, 6, 1
        add     x0, x29, 24
        strb    w1, [x29,28]
        bl      bar

But there is still some things missing but it is still a much better job than
what happens on x86.