On Tue, 1 Jul 2008 23:41:01 -0700 David Brownell <[email protected]> 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 <[email protected]>
> Acked-by: Adrian Bunk <[email protected]>
> ---
> 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);
On Wed, Jul 02, 2008 at 01:45:02AM -0700, Andrew Morton wrote:
> On Tue, 1 Jul 2008 23:41:01 -0700 David Brownell <[email protected]> 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 <[email protected]>
> > Acked-by: Adrian Bunk <[email protected]>
> > ---
> > 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.
>...
Unless David is faster I plan to do this after the patch went into
Linus' tree.
E.g. rtc-ramtron-fm3130-rtc-support.patch in 2.6.26-rc5-mm3 adds a new
user, and it should create less hassle if the actual removal of the
#define's happens around 2.6.27-rc1 when everything is merged into
Linus' tree.
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed