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¬e=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 uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
