treewide: Add and use ADD_MOD macro
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From: Randy Dunlap on 29 Mar 2010 15:50 On Sun, 28 Mar 2010 14:57:27 -0700 Joe Perches wrote: > Add a macro for the somewhat common use of > > (something + value) % value > > drivers/net/sundance.c includes a change from > a for(;test;add) loop to while (test) {... add}; > because the test uses ADD_MOD > > Compile tested only > > Signed-off-by: Joe Perches <joe(a)perches.com> > --- > include/linux/kernel.h | 1 + > drivers/ata/libata-eh.c | 2 +- > drivers/media/video/ov511.c | 2 +- > drivers/media/video/usbvideo/usbvideo.c | 2 +- > drivers/net/dl2k.c | 8 ++++---- > drivers/net/sundance.c | 4 ++-- > drivers/pci/dmar.c | 6 +++--- > drivers/scsi/3w-9xxx.c | 2 +- > drivers/staging/wavelan/wavelan_cs.c | 10 +++++----- > drivers/usb/misc/sisusbvga/sisusb_con.c | 4 ++-- > drivers/video/console/vgacon.c | 4 ++-- > sound/oss/vwsnd.c | 6 +++--- > 12 files changed, 26 insertions(+), 25 deletions(-) > > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index 7f07074..c96b1ac 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -63,6 +63,7 @@ extern const char linux_proc_banner[]; > (((x) + ((__divisor) / 2)) / (__divisor)); \ > } \ > ) > +#define ADD_MOD(x, y) (((x) + (y)) % (y)) > > #define _RET_IP_ (unsigned long)__builtin_return_address(0) > #define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; }) It would be better not to evaluate y more than one time. Also it's not safe for 64-bit 'y' on i386, right? Looks like it would cause missing reference to __imoddi3 or whatever it is called. so it can easily be misused IMO. --- ~Randy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Joe Perches on 29 Mar 2010 16:10
On Mon, 2010-03-29 at 12:47 -0700, Randy Dunlap wrote: > On Sun, 28 Mar 2010 14:57:27 -0700 Joe Perches wrote: > > Add a macro for the somewhat common use of > > (something + value) % value > > because the test uses ADD_MOD > > --- a/include/linux/kernel.h > > +++ b/include/linux/kernel.h > > +#define ADD_MOD(x, y) (((x) + (y)) % (y)) > It would be better not to evaluate y more than one time. That could be said for nearly all the convenience macros in kernel.h > Also it's not safe for 64-bit 'y' on i386, right? > Looks like it would cause missing reference to __imoddi3 > or whatever it is called. Which is also true for nearly all the convenience macros in kernel.h > so it can easily be misused IMO. etc. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |