I understand that avr-libc is compiled by avr-gcc and that a defective avr-gcc could possibly lead to a flawed copy of the library binary -- at least the stuff written in C like random(). But here's the thing. When I install my Arduino package for Windows, I get a precompiled copy of avr-libc, so it (presumably) doesn't matter that the package also contains the bad compiler -- and in fact it does include the "bad" 4.3.0 version -- I'm still getting the "good" library. This is just speculation here, but I'm guessing that that means the Windows avr-libc must have been compiled with a different compiler (4.3.2?) than the one distributed alongside it (4.3.0) in the Arduino package.
In Linux-land, the paradigm is different. Unlike Windows, the Arduino Linux package doesn't supply either avr-gcc or avr-libc. Instead, it requires the user to procure these from "elsewhere", and this leads to the problem we have been discussing. Perhaps we need to change this to match Windows for consistency's sake if nothing else. Many thanks again for your replies and clear explanation. Mikal -----Original Message----- From: Weddington, Eric [mailto:ewedding...@cso.atmel.com] Sent: Sunday, January 04, 2009 10:01 PM To: Mikal Hart; Joerg Wunsch; AVR-libc-dev@nongnu.org Subject: RE: [avr-libc-dev] bug in rand()/random()/do_rand()/do_random( ) > -----Original Message----- > From: Mikal Hart [mailto:mh...@sundial.com] > Sent: Sunday, January 04, 2009 8:38 PM > To: Weddington, Eric; 'Joerg Wunsch'; AVR-libc-dev@nongnu.org > Subject: RE: [avr-libc-dev] bug in > rand()/random()/do_rand()/do_random( ) > > > So far the evidence that you present points somehow to a > problem with > 4.3.0, since this user said it works with 4.3.2. There are > known problems > with 4.3.0 (for the AVR target) so I'm not totally surprised > that 4.3.2 > would fix it. > > The only thing that makes me uneasy is that I don't see > exactly where the > defective compiler comes into play. Avr-libc is compiled with avr-gcc. The random functions in avr-libc are written in C, hence the generated code is dependent on the avr-gcc compiler. Avr-gcc 4.3.0 has code generation problems that are known. Avr-gcc 4.3.2 fixes those code generation problems. So it is a matter of what version of avr-gcc was used to compile avr-libc. Is that any clearer? _______________________________________________ AVR-libc-dev mailing list AVR-libc-dev@nongnu.org http://lists.nongnu.org/mailman/listinfo/avr-libc-dev
