Re: 68K GNU Compiler

On Wed, Aug 08, 2012 at 05:13:53PM +0200, Michael Schnell wrote:
> I remember that the 68332 documentation does provide cycle count.
> the calculation is complicated, as it depends on the count of cycles
> necessary to access the different memory areas that are accessed.
> 
> In fact I found that the compiler does create decent code for
> non-volatile variables but when specifying volatile the code gets a
> lot worse, even though  the normal code already fulfills all specs
> necessary for volatile variables.

There does seem to be some interesting bugs related to volatile:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33068

Also a claim that newer gcc's generate worse and worse code for m68k:

http://www.natami.net/knowledge.php?b=3&note=8

It sounds like gcc 4.3, 4.4 and 4.5 have been improving again with
each release.  Apparently 4.2 was the worst one to use.

-- 
Len Sorensen
_______________________________________________
uClinux-dev mailing list
[email protected]
http://mailman.uclinux.org/mailman/listinfo/uclinux-dev
This message was resent by [email protected]
To unsubscribe see:
http://mailman.uclinux.org/mailman/options/uclinux-dev