| Message ID | 1457185628-23304-1-git-send-email-richard.weiyang@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Is this (quite old) patch still relevant? Thanks, /mjt 05.03.2016 16:47, Wei Yang wrote: > According to linux kernel commit <89c1e79eb30> ("linux/bitmap.h: improve > BITMAP_{LAST,FIRST}_WORD_MASK"), these two macro could be improved. > > This patch takes this change and also move them all in header file. > > Signed-off-by: Wei Yang <richard.weiyang@gmail.com> > --- > include/qemu/bitmap.h | 7 ++----- > util/bitmap.c | 2 -- > 2 files changed, 2 insertions(+), 7 deletions(-) > > diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h > index 0e33fa5..864982d 100644 > --- a/include/qemu/bitmap.h > +++ b/include/qemu/bitmap.h > @@ -58,11 +58,8 @@ > * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit > */ > > -#define BITMAP_LAST_WORD_MASK(nbits) \ > - ( \ > - ((nbits) % BITS_PER_LONG) ? \ > - (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \ > - ) > +#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) > +#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) > > #define DECLARE_BITMAP(name,bits) \ > unsigned long name[BITS_TO_LONGS(bits)] > diff --git a/util/bitmap.c b/util/bitmap.c > index 40aadfb..43ed011 100644 > --- a/util/bitmap.c > +++ b/util/bitmap.c > @@ -157,8 +157,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, > return result != 0; > } > > -#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) > - > void bitmap_set(unsigned long *map, long start, long nr) > { > unsigned long *p = map + BIT_WORD(start); >
On 14/09/2016 09:33, Michael Tokarev wrote: > Is this (quite old) patch still relevant? Yes, I think it's a nice cleanup. The interesting bit is that it expands nbits exactly once. Paolo > Thanks, > > /mjt > > 05.03.2016 16:47, Wei Yang wrote: >> According to linux kernel commit <89c1e79eb30> ("linux/bitmap.h: improve >> BITMAP_{LAST,FIRST}_WORD_MASK"), these two macro could be improved. >> >> This patch takes this change and also move them all in header file. >> >> Signed-off-by: Wei Yang <richard.weiyang@gmail.com> >> --- >> include/qemu/bitmap.h | 7 ++----- >> util/bitmap.c | 2 -- >> 2 files changed, 2 insertions(+), 7 deletions(-) >> >> diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h >> index 0e33fa5..864982d 100644 >> --- a/include/qemu/bitmap.h >> +++ b/include/qemu/bitmap.h >> @@ -58,11 +58,8 @@ >> * find_next_bit(addr, nbits, bit) Position next set bit in *addr >> >= bit >> */ >> >> -#define >> BITMAP_LAST_WORD_MASK(nbits) \ >> - >> ( \ >> - ((nbits) % BITS_PER_LONG) >> ? \ >> - (1UL<<((nbits) % BITS_PER_LONG))-1 : >> ~0UL \ >> - ) >> +#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & >> (BITS_PER_LONG - 1))) >> +#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & >> (BITS_PER_LONG - 1))) >> >> #define DECLARE_BITMAP(name,bits) \ >> unsigned long name[BITS_TO_LONGS(bits)] >> diff --git a/util/bitmap.c b/util/bitmap.c >> index 40aadfb..43ed011 100644 >> --- a/util/bitmap.c >> +++ b/util/bitmap.c >> @@ -157,8 +157,6 @@ int slow_bitmap_andnot(unsigned long *dst, const >> unsigned long *bitmap1, >> return result != 0; >> } >> >> -#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % >> BITS_PER_LONG)) >> - >> void bitmap_set(unsigned long *map, long start, long nr) >> { >> unsigned long *p = map + BIT_WORD(start); >> > > >
05.03.2016 16:47, Wei Yang wrote: > According to linux kernel commit <89c1e79eb30> ("linux/bitmap.h: improve > BITMAP_{LAST,FIRST}_WORD_MASK"), these two macro could be improved. > > This patch takes this change and also move them all in header file. Applied to -trivial, thank you! /mjt
On Thu, Sep 29, 2016 at 07:11:39PM +0300, Michael Tokarev wrote: >05.03.2016 16:47, Wei Yang wrote: >>According to linux kernel commit <89c1e79eb30> ("linux/bitmap.h: improve >>BITMAP_{LAST,FIRST}_WORD_MASK"), these two macro could be improved. >> >>This patch takes this change and also move them all in header file. > >Applied to -trivial, thank you! > Thanks :-) Have a good day~ >/mjt
diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h index 0e33fa5..864982d 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -58,11 +58,8 @@ * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit */ -#define BITMAP_LAST_WORD_MASK(nbits) \ - ( \ - ((nbits) % BITS_PER_LONG) ? \ - (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \ - ) +#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) +#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) #define DECLARE_BITMAP(name,bits) \ unsigned long name[BITS_TO_LONGS(bits)] diff --git a/util/bitmap.c b/util/bitmap.c index 40aadfb..43ed011 100644 --- a/util/bitmap.c +++ b/util/bitmap.c @@ -157,8 +157,6 @@ int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, return result != 0; } -#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) - void bitmap_set(unsigned long *map, long start, long nr) { unsigned long *p = map + BIT_WORD(start);
According to linux kernel commit <89c1e79eb30> ("linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK"), these two macro could be improved. This patch takes this change and also move them all in header file. Signed-off-by: Wei Yang <richard.weiyang@gmail.com> --- include/qemu/bitmap.h | 7 ++----- util/bitmap.c | 2 -- 2 files changed, 2 insertions(+), 7 deletions(-)