Messages in this thread | | | Date | Wed, 2 Jul 2008 01:45:02 -0700 | From | Andrew Morton <> | Subject | Re: [patch 2.6.26-mmotm] rtc: BCD codeshrink |
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On Tue, 1 Jul 2008 23:41:01 -0700 David Brownell <david-b@pacbell.net> wrote:
> This updates <linux/bcd.h> to define the key routines as constant > functions, which the macros will then call. Newer code can now > call bcd2bin() instead of SCREAMING BCD2BIN() TO THE FOUR WINDS. > > This lets each driver shrink their codespace by using N function > calls to a single (global) copy of those routines, instead of N > inlined copies of these functions per driver. > > These routines aren't used in speed-critical code. Almost all > callers are in the RTC framework. Typical per-driver savings is > near 300 bytes. > > Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> > Acked-by: Adrian Bunk <bunk@kernel.org> > --- > include/linux/bcd.h | 9 +++++++-- > lib/Makefile | 2 +- > lib/bcd.c | 14 ++++++++++++++ > 3 files changed, 22 insertions(+), 3 deletions(-) > > --- a/include/linux/bcd.h 2008-06-30 16:44:26.000000000 -0700 > +++ b/include/linux/bcd.h 2008-06-30 21:38:24.000000000 -0700 > @@ -10,8 +10,13 @@ > #ifndef _BCD_H > #define _BCD_H > > -#define BCD2BIN(val) (((val) & 0x0f) + ((val)>>4)*10) > -#define BIN2BCD(val) ((((val)/10)<<4) + (val)%10) > +#include <linux/compiler.h> > + > +unsigned bcd2bin(unsigned char val) __attribute_const__; > +unsigned char bin2bcd(unsigned val) __attribute_const__; > + > +#define BCD2BIN(val) bcd2bin(val) > +#define BIN2BCD(val) bin2bcd(val)
It'd be good to nuke these things now.
Unfortunately you didn't cc the list where nukers lurk. Please do cc linux-kernel on kernel-wide patches.
> /* backwards compat */ > #define BCD_TO_BIN(val) ((val)=BCD2BIN(val)) > --- a/lib/Makefile 2008-06-30 16:44:26.000000000 -0700 > +++ b/lib/Makefile 2008-06-30 21:38:24.000000000 -0700 > @@ -13,7 +13,7 @@ lib-$(CONFIG_SMP) += cpumask.o > > lib-y += kobject.o kref.o klist.o > > -obj-y += div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ > +obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ > bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o > > ifeq ($(CONFIG_DEBUG_KOBJECT),y) > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > +++ b/lib/bcd.c 2008-06-30 21:38:24.000000000 -0700 > @@ -0,0 +1,14 @@ > +#include <linux/bcd.h> > +#include <linux/module.h> > + > +unsigned bcd2bin(unsigned char val) > +{ > + return (val & 0x0f) + (val >> 4) * 10; > +} > +EXPORT_SYMBOL(bcd2bin); > + > +unsigned char bin2bcd(unsigned val) > +{ > + return ((val / 10) << 4) + val % 10; > +} > +EXPORT_SYMBOL(bin2bcd);
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