On Sun, Sep 24, 2006 at 10:06:51PM +0200, Daniel Smolik wrote: > Hi, > when I compile eeprom.c with gcc-3.3 works without fix. May be this isn't > problem in eeprom.c but in gcc or gcc usage. What do you mean ?
Hi Daniel, The fix works because once you declare something as int, compiler *has* to align it at a 4-byte boundary, if it would not do that, that would be a bug. For a char array there is probably no alignment requirement, so it's perfectly ok for it to be unaligned. The fact that you do not see the same behaviour with gcc-3.3 is not surprising either: depending on the implemented optimizations different compilers may use different layouts of variables in memory, so in some cases buf2 may be aligned. Note that compiling eeprom.c with gcc-4.1 and -O0 instead of -O2 also does not trigger the bug. You can force alignment of variables in gcc using the alignment attribute, for example writing something like char foo __attribute__ ((aligned(4))); should cause foo to be aligned on a 4-byte boundary. Hm, it's confusing, because I think I tried this before on buf2 and it did not work (got a gcc warning about ignored attribute, maybe I did not spell it correctly?). Now it appears to work though :-/. I guess I need to rework my solution to use this instead. Best regards, -- Jurij Smakov [EMAIL PROTECTED] Key: http://www.wooyd.org/pgpkey/ KeyID: C99E03CC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
