Bloated Struct Problem

[. .]

On Fri, Jun 5, 2009 at 5:30 PM, Ian Lance Taylor<iant@google.com> wrote:
> ". ." <pkejjy@gmail.com> writes:
>
>> (In other words, I think the default for x86(-64) should be packed,
>> but I'll leave it to others to have that flame war.)
>
> The ABI can not change.  Changing that now would prevent linking object
> files compiler by different compilers together safely, as they would use
> different offsets for accessing struct fields.

Yuck -- I see your point.  But, there could still be a commandline
switch to pack all structs (like -Os, but for data).  No, I don't
expect anyone to actually create this anytime soon, but it would be a
handy tool for manycore optimization endeavors.

>
> In any case, different programs have different tradeoffs here.  Some
> programs prefer the faster access of aligned fields, some programs
> prefer the reduced memory usage of packed fiels.  No single default can
> be satisfactory for everybody, but nevertheless there must be a default.

Yes, clearly.

>
> Ian
>