On, Wed, 23 Oct 2013 17:36:41Richard Biener wrote:
>
> if bitregion_start/end are used after the adjust_address call then they have
> to be adjusted (or bitpos left in place). In fact why we apply byte-parts of
> bitpos here only if offset != 0 is weird. OTOH this code is _very_ old...
> what happens if you remove the whole case?
>
> Richard.
>

If I remove that code completely...

Than changes nothing ARM at -O2.
and on x86 at -O2 this changes:

        .cfi_startproc
        movl    k, %eax
        leal    (%eax,%eax,2), %eax
-       leal    ss+8(,%eax,4), %eax
-       movl    $1, 16(%eax)
+       leal    ss+16(,%eax,4), %eax
+       movl    $1, 8(%eax)
        movl    k, %eax
        leal    (%eax,%eax,2), %eax
-       leal    ss+8(,%eax,4), %eax
-       movl    16(%eax), %eax
+       leal    ss+16(,%eax,4), %eax
+       movl    8(%eax), %eax
        cmpl    $1, %eax
        jne     .L5
        xorl    %eax, %eax


that does not really make any difference.

So removing that code looks like a nice alternative.

What do you think?

Bernd.