Re: [head tinderbox] failure on arm/arm

In message: <20061112192810.GC1173_at_rambler-co.ru>
             Ruslan Ermilov <ru_at_freebsd.org> writes:
: On the other hand, having GCC align "struct foo { char x[11]; }"
: on a four-byte boundary (other than for backward compatibility)
: doesn't make too much sense to me.

It makes a lot of sense, actually, even on i386, which is
why the standard allows the compiler a lot of leeway to
pad and align such structure.  For example, consider this
structure assignment:

    struct foo a,b;
    a = b;

The structure copy here is a LOT faster if the structures
are always suitably aligned and padded.  If the compiler
pads your sample struct to 12 bytes and 4-aligns, the
structure copy here can be done with 3 aligned 32-bit moves.
Even on i386, aligned operations are a lot faster than
unaligned ones.

The code mentioned in the original post is simply broken;
it does not comply with the ISO C Standard.

Tim Kientzle