Skip to content

Commit

Permalink
lib: bitmap: make the start index of bitmap_set unsigned
Browse files Browse the repository at this point in the history
The compiler can generate slightly smaller and simpler code when it
knows that "start" is non-negative.

Also, use the names "start" and "len" for the two parameters in both
header file and implementation, instead of the previous mix.

Signed-off-by: Rasmus Villemoes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
Villemoes authored and torvalds committed Aug 7, 2014
1 parent 877d9f3 commit fb5ac54
Show file tree
Hide file tree
Showing 2 changed files with 6 additions and 6 deletions.
2 changes: 1 addition & 1 deletion include/linux/bitmap.h
Original file line number Diff line number Diff line change
Expand Up @@ -112,7 +112,7 @@ extern int __bitmap_subset(const unsigned long *bitmap1,
const unsigned long *bitmap2, unsigned int nbits);
extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);

extern void bitmap_set(unsigned long *map, int i, int len);
extern void bitmap_set(unsigned long *map, unsigned int start, int len);
extern void bitmap_clear(unsigned long *map, int start, int nr);
extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
unsigned long size,
Expand Down
10 changes: 5 additions & 5 deletions lib/bitmap.c
Original file line number Diff line number Diff line change
Expand Up @@ -274,21 +274,21 @@ int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
}
EXPORT_SYMBOL(__bitmap_weight);

void bitmap_set(unsigned long *map, int start, int nr)
void bitmap_set(unsigned long *map, unsigned int start, int len)
{
unsigned long *p = map + BIT_WORD(start);
const int size = start + nr;
const unsigned int size = start + len;
int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);

while (nr - bits_to_set >= 0) {
while (len - bits_to_set >= 0) {
*p |= mask_to_set;
nr -= bits_to_set;
len -= bits_to_set;
bits_to_set = BITS_PER_LONG;
mask_to_set = ~0UL;
p++;
}
if (nr) {
if (len) {
mask_to_set &= BITMAP_LAST_WORD_MASK(size);
*p |= mask_to_set;
}
Expand Down

0 comments on commit fb5ac54

Please sign in to comment.