On Wed, 2015-09-09 at 12:37 -0400, Tom Rini wrote: > On Wed, Sep 09, 2015 at 11:22:25AM -0500, Scott Wood wrote: > > On Tue, 2015-09-08 at 21:01 +0300, ivan.khoronzhuk wrote: > > > Hi, Andreas > > > > > > On 07.09.15 14:43, Andreas Bießmann wrote: > > > > From: Heiko Schocher <h...@denx.de> > > > > > > > > introduce BIT() definition, used in at91_udc gadget > > > > driver. > > > > > > > > Signed-off-by: Heiko Schocher <h...@denx.de> > > > > [remove all other occurrences of BIT(x) definition] > > > > Signed-off-by: Andreas Bießmann <andreas.de...@googlemail.com> > > > > --- > > > > Full buildman is running > > > > > > > > > > .... > > > > > > > > > > > +#define BIT(nr) (1UL << (nr)) > > > > > > Why UL? Why not simply 1 << (nr)? > > > > That would give the wrong result for nr == 31 if used as a 64-bit number, > > and > > would produce undefined behavior for nr >= 32 (though even with 1UL that > > would be undefined on 32-bit builds). > > > > > What if I need set ULL bit on 32-bit system? > > > Thanks for explanation. > > > > Yes, ULL would be better. > > That would be BIT_ULL(nr) ? I want to assume that there was some care > given upstream here. It was about 2 years ago now the kernel added a > specific BIT_ULL and family in addition to BIT(nr) from back in 2007.
A quick search didn't turn up much justification for keeping them separate (and it seems like using BIT where BIT_ULL is needed could be a source of difficult bugs), but sure, we don't want to encourage writing driver code that will break on Linux. -Scott _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
