[coldfire-gnu-discuss] Coldfire Toolchain packed structure bug version 4.1.30 and newer

[Carlos O'Donell]

On Wed, Apr 18, 2007 at 05:30:56PM -0400, Malnar, Tom wrote:
> Thank Carlos, I really appreciate the quick follow up.  
> 
> I just wanted to mention (may help your investigation) that there may be
> two issues.  
> 
> The assembly actually produced when the alignment was 1 is very bad.  
> I assume when alignment was 1 that my 'short' variable was treated as
> two bytes.  To move two bytes, something like:
> 
>   moveal %fp@(-4),%a0
>   clrl %d0
>   moveb %d0,%a0@
>   mov3ql #2,%d0
>   moveb %d0,%a0@(1)
> 
> would do the job.  The code it produced was:
> 
>   12:   206e fffc       moveal %fp@(-4),%a0
>   16:   1010            moveb %a0@,%d0
>   18:   4281            clrl %d1
>   1a:   c081            andl %d1,%d0
>   1c:   1000            moveb %d0,%d0
>   1e:   1080            moveb %d0,%a0@
>   20:   1028 0001       moveb %a0@(1),%d0
>   24:   4281            clrl %d1
>   26:   c081            andl %d1,%d0
>   28:   1000            moveb %d0,%d0
>   2a:   a541            mov3ql #2,%d1
>   2c:   8081            orl %d1,%d0
>   2e:   1000            moveb %d0,%d0
>   30:   1140 0001       moveb %d0,%a0@(1)
>   
> Not sure if the issues are related or not, but it should probably be
> investigated.  

You need to turn on the compiler optimizations with "-O1" or higher if
you want optimized code.

If at "-O1" or higher you continue to see cases where the compiler is
doing a poor job please report them to the list and we will look at
them.

Cheers,
Carlos.
-- 
Carlos O'Donell
CodeSourcery
carlos at codesourcery.com
(650) 331-3385 x716